FIVE FROGS WOODWORKING

This is a continuation of my last blog post. This project is taking longer than expected. I have cut seven of the different wood samples. I will post my findings of these seven, as I am not sure how long it will take me to get to the rest of them.

I decided to make these test puzzles as close to the same as possible. So, I cut them all using the same saw, the same brand, size, and style of sawblades, and the same puzzle piece style. These are all 8″ x 8″ blanks (except for one I will discuss when I get to it). I cut the puzzles using my DeWalt scroll saw with Pegas 2/0R MGT blades. I cut them in what I call the dragon tail piece style. They all seven have roughly 40 pieces (except for the smaller one).

The samples I have managed to cut at this point are the five varieties from the Boulter sample pack, a piece of cherry Appleply, and the piece of MDF core with maple face veneer. I also cut additional puzzles from the extra sapele, okoume, and meranti blanks. These three additional puzzles are not the dragon tails style of puzzle piece.

I share below my experiences with these woods. As always, these are my personal experiences. Others may disagree with me, which is fine. Some of the pictures you will see are greatly magnified to better show what I have learned. I took these magnified pictures with a Carson xOrb Digital Viewer which magnifies 68X on a 27″ monitor. They do not look as drastic in real life as some of these photos might indicate!

Meranti

I started with the meranti. It intrigued me due to its rather neutral look. It is not bland like Baltic birch but has a very consistent looking grain structure. It was lighter than some of the other woods. The piece on top in the below picture has Danish oil on it to bring out the grain.

I did discover that the surface was what a wood worker would call an “open grain”, which means it was rather porous. Open grain woods do not typically take stains very evenly. Even uncut and sanded, this surface was rough looking. This photo taken with my cell phone while I was sitting at the saw shows the open cell structure of the meranti wood.

I found this wood to splinter rather easily. I could see pieces flaking off along the grain as I was cutting it. This was on the top surface as I cut, which is where the teeth of the blade are pressing down into the wood. You often have splintering on the bottom side, but this was happening on the top side. The below photo was taken with my cell phone camera while cutting. This was the worst of all the woods tested for this.

The backside was much worse, with entire pieces being torn out. The picture below shows the worst incidence of this with a .5 mm mechanical pencil for comparison. Photo taken with zOrb.

Of the seven varieties discussed here, I feel this was the second weakest as far as structural strength. The first thing cut with these puzzles is the edge all around the puzzle. I tested all of the edge debris, and this was the second easiest to break. This was obviously not scientific with gauges and meters and such, but I did this to all seven plywood varieties using several pieces of debris from each puzzle.

This puzzle I opted to finish with acrylic spray paint. You can see how the grain structure did not allow for a very smooth surface. I do not think this hurts the puzzle but gives it maybe a rustic appearance.

Here is a closeup of the paint.

Also, the weakness of the wood was proven when removing the pieces from the sacrificial cardboard used while painting. One of the pieces broke! You can see it in the below picture as well as the above picture. I have glued it back together. It is probably stronger than it was but will always be a little weak. I will be listing this puzzle for sale on Etsy but will point out the broken and mended piece. It will be shipped with the adjacent piece inserted for support.

I was disappointed with the other puzzle I cut from this as well. The below picture is a little out of focus, but you can see all of the tear out from the bottom.

Here is a closeup some of the tear out.

I find this to be unacceptable. I have not made up my mind on what I will do with this puzzle. I have done nothing to finish it yet. It may just go in the kindling pile.

I personally will not buy any more meranti plywood for making puzzles.

Okoume

Next was the okoume. At 7mm, this was the thickest of the Boulter samples. The piece on top in the below picture has Danish oil on it to bring out the grain.

This wood was subject to a lot less splintering than the meranti was.

Here is a close up of the worst spot I could find on the top, with a .5mm pencil lead for comparison.

The bottom side was fuzzy, like most wood is after being cut with a saw.

Below is a picture of the edge cut done at the beginning of any my dragon tails puzzles. For this wood comparison test, I was breaking these in multiple locations to get a feel for the strength of the plywood. The okoume was as good as any of them.

I did find one location with a small void.

Here is the finished and painted puzzle. This puzzle will be listed on Etsy.

You can see the grain structure through the paint on the okoume as well, but it is much less severe than the meranti or the sapelle. Here is a close up.

I did a second puzzle with the okoume. It was cut in my usual piece style, but with a small frog border.

This puzzle I opted to finish with 5 different colors of Danish oil finish. This puzzle will be listed on Etsy.

I felt this was a decent plywood to work with for puzzle cutting. I have not found it locally, and I like the Appleply I have been using, so I probably will not be making many puzzles from it. If it was sourced locally, I would use it.

Sapelle

Next came the sapelle. The piece on top in the below picture has Danish oil finish applied to bring out the wood beauty.

This wood splintered on the top as it was cut, but nowhere nearly as bad as the meranti. The picture below shows one such location on the right by the .5mm pencil lead. It also shows a tip blow out on the left. Remember, this was taken with the zOrb device, and does not look bad to the naked eye.

The backside had some as well.

The finished puzzle is fine. You can see more grain structure than with the okoume, but less than the meranti.

Here is a close up.

The other panel, I cut differently and coated it with just a neutral Danish oil finish. I will probably list this on Etsy, but I am tempted to keep it for myself. I was unable to capture it with my photographic skills, but that piece shimmers in the light as you move it around. It is just flat out gorgeous in its iridescence.

I do notice with this wood that it is very difficult to pick this puzzle up to flip it over. There is almost no friction between the pieces and if you pick it up, it will fall apart. I have to use two pieces of cardboard to sandwich it to flip it over.

Like the okoume, I would not hesitate to use this in the future but would not go out of my way to obtain more.

Boulter provided cherry single ply core

This wood was extremely frustrating to me. I love cherry and had high hopes for this stuff. Like the previous wood selections, the top panel below has a coat of Danish oil finish on it.

This wood is very thin, and very light. It offers almost no resistance to the blade as you are cutting. It was almost like pushing through water or something. I found it to be uncontrollable. I could not spin the wood around the blade without over running my target. I ruined the first panel and tossed it in the fire. I started the second panel and gave up early. I could not even cut the edge of the puzzle off, much less attempt to cut the more challenging dragon tail pieces. I ended up cutting a chunk off to remove the evidence of my efforts.

I moved on to the Baltic birch. As I was cutting the Baltic birch, I decided to give this cherry another shot by using a dull blade. I cut in the Baltic birch until the blade was bending quite a bit from pushing hard enough to get it to cut. I then switched to the cherry and cut the entire puzzle (now smaller than desired) with one extremely dull blade.

I found that it did not have any splintering problems. Here is a representative picture of the top side taken with the zOrb showing the quality of the cut.

The backside was typically fuzzy.

I finished this puzzle using Danish oil.

The puzzle looks great. However, I find the wood to be very weak. The strength test I described above showed the wood to break with almost no effort at all. In fact, one of the pieces broke while I was just rubbing a little finish on it.

Yes, I can glue it, but I think it is symptomatic of problems the entire puzzle will have. I do not think I will list this for sale. I think it will be a loaner demo puzzle until it is nothing but splinters and toothpicks.

I found this wood to be unacceptable for my puzzle purposes.

Baltic Birch

I have used a lot of Baltic birch in the past and will use more in the future. It seems to be easy to find locally and is usually of fairly good quality.

One of the issues with Baltic birch is that sometimes it has a surface patch on it. The picture below is an example of such a patch. It is not shown in the above photo, but one of those panels does have a surface patch.

This sample of Baltic birch splintered quite a bit more than I expected it to. I have noticed this is becoming more common with the Baltic birch I have been using. A couple of other puzzle cutters have commented on this issue in a Facebook puzzle group I am a member of. This is one of the reasons I have been looking for a different wood to use. In the picture below, you can see the splintered wood laying on the surface, and to the left and slightly below that you can see the divot it came out of.

Here is the cut puzzle.

Since this is pretty boring wood, I opted to spray paint this one as well. You can see the grain lines show through the paint with this wood as well.

Here is a close up of the painted wood. Some of the grooves are natural to the wood, and a couple are from the missing splinters.

Here is the surface patch.

I have no problem using Baltic birch but was really looking for something better.

Cherry Appleply

This brings us to the cherry Appleply sample. This was top of my list going into this, and it has pretty much stayed there.

This stuff is a joy to cut. There is really no splintering top or bottom while cutting. This is the worst spot I could find on the top of the panel. Remember, this is magnified something like 60 times by the zOrb.

This is the worst spot I could find on the bottom of the panel. All of those whiskers go away with a little bit of sanding when done cutting. No divots or grooves left behind.

Here is the cut but unfinished puzzle.

I opted to finish this with 5 different shades of Danish oil. This picture does not do it justice.

Once the Danish oil finish has cured, this will be listed on Etsy. It is cool in my workspace right now, so it is taking longer to cure than I planned for.

MDF core maple panel

This was the big surprise for me. I tend to sneer at MDF for certain things, such as skinny puzzle pieces. This actually is a good product worth looking for more of. I apparently failed to get a standalone picture of the uncut panel, but here is the cut puzzle.

This stuff cut beautifully. It seems to be as strong as the majority of the plywood samples. It did produce much finer dust than the rest of them. Like the Appleply, splintering was basically non-existent. Here is a view of the top side.

And here is a view of the backside.

Light sanding after cutting removed all of the little whiskers.

Once again, I opted to finish this with five shades of Danish oil finish. This is a little bit different, as the previous examples finished with the Danish oil were on darker woods. This being maple, the same colors of finish produced wildly different results.

The difference is very subtle, but the light-colored pieces in the picture below are actually two different shades of finish.

This will also be listed on Etsy.

Summary

I still have more varieties of wood choices to cut. But from what I have done so far, the cherry Appleply is my wood of choice. Second to that would be the MDF core maple panel product. I think the Meranti and the single ply cherry core plywood are unacceptable for what I do.

As far as any hard analytical data, I kept records of the number of blades used and the amount of time spent on cutting each puzzle. They are listed in the table below. It is a pretty small sample size for real conclusions.

Note that the cutting time is not the vast majority of time spent on these overall. Applying finish, sanding, etc take up a considerable amount of time. Add in time for boxing, labeling, picture taking and editing for Etsy listings, creating the Etsy listing, etc, come close to doubling the time in some cases. The smaller the puzzle, the more relative “admin” time involved.

Some of these are already listed on my Etsy website at FiveFrogsWoodworking, and more will be as time moves on. I was hoping to get these listed earlier in the month to allow for more time before Christmas, but life sometimes interferes in manmade plans.

Happy Puzzling!

Bob

Boulter sample pack

The catalyst for this puzzle board comparison was the announced availability of sampler packs from Boulter Plywood with five 8″ x 8″ samples of different varieties of plywood. Dee Rogers on her Facebook group page explained that Chris Boulter had arranged for these sampler packs so puzzle cutters could try out five different types of plywood and see how they like them. BoulterPlywood.com

I thought “Why not?” In August, I finally got around to calling to order a sampler pack. It was pointed out that shipping costs might make it worthwhile to order more than one pack to reduce the impact per order. So, I ordered three packs. $24 of wood, and $17.20 in shipping charges from the east coast to the Spokane, Washington area. So that is 960 square inches of material for $41.20, or $6.18 per square foot. Just in comparison, two weeks later, I bought six 4′ x 4′ panels of Appleply from States Industries in Oregon. The total cost was $585.83 delivered (only $71 of that was shipping). That equates to $6.10 per square foot. The last Baltic birch I bought locally was $61.03 for a 5′ x 5′ panel, or $2.44 per square foot.

The price per square foot is probably not a fair comparison, as I suspect larger pieces from Boulter Plywood to here would be pretty expensive to ship. If you have a local lumber store or specialty store, that is probably your best source price wise. Many of them will also order wood they do not normally carry.

Here is a sampler pack. They are helpfully marked on one edge with a single letter corresponding to the species name.

Since I have three packs, I decided to put a coat of Danish Oil on one side of each variety to see what color is brought out. I also want to see if a finish of some sort reduces the amount of splintering on the back side of the puzzle while cutting, so the oiled samples will be cut with the oil side down (once the oil dries).

The Danish oil really brought out the grain and shows what the wood looks like. Well, except for the Baltic birch. Baltic Birch just looks… bland? The sapele sample is almost iridescent as you tilt it around in the light.

Okoume – Okoume comes from the central African country of Gabon. If you are interested, information about it is available on The Wood Database. I wanted to verify it is not listed on the bad list. It is shown as vulnerable but not on the CITES list. This particular sample is the thickest of them, advertised as 7mm. I measured all of the samples with a dial caliper, and this was actually 7mm. All layers are made of rotary cut okoume. This piece is marine grade plywood, meaning the adhesive meets a specific standard for being water and boil proof (WBP).

Sapelle – Sapelle is from tropical Africa. It is one of the very many woods often lumped together under the mahogany label, although it is not a true mahogany. The Wood Database has good information on it. Like the okoume, it is not listed on the CITES list, but is considered vulnerable. This is also a marine grade plywood. All layers are made of rotary cut sapelle.

Meranti – Meranti is one of many different species that is referred to as Philippine Mahogany, which is no relation to real mahogany from Honduras. It is found throughout Southeast Asia, and although some varieties are vulnerable, some Meranti comes from sustainable sources. Dark Red Meranti | The Wood Database. This is also a marine grade plywood. All layers are made of rotary cut meranti.

Boulter provided cherry – This is the first product examined that is made of two different materials. The outer face veneer is obviously cherry. It is plain sliced. The single inner veneer is poplar. Here are the Wood Database pages for both of those woods.

• Yellow poplar | The Wood Database,
• Poplar, Cottonwood, and Aspen: What’s What? | The Wood Database, and
• Black Cherry | The Wood Database (Hardwood) (wood-database.com).

Notice that most poplar wood used for furniture is not really poplar but comes from the tulip tree. Actual wood from a poplar tree is kind of a trash wood and is used for stuff like pallets, firewood, and making paper. Confusing, right?

This is the thinnest of the samples so far. In the edge view picture below, you can see how thin the face veneers are. Since there is only a single inner ply, I have included a view of both the end grain and the side grain of the inner ply.

Baltic birch – I have been able to easily find this just about everywhere I have lived (residences in 13 different locales in 40 years). Most of it is from nations in the Baltic area, such as Russia, Finland, etc. Baltic Birch | The Wood Database. Baltic birch is a great product even though it is visually boring. It is strong, stable, and flat. I have been using different thicknesses of it for years to make shop jigs, shop cabinets, shop tools, etc. I turned to the 1/4″ version to make puzzles when I decided to get serious about puzzles. All layers are made with rotary cut birch. You can see there are five fairly equally thick layers.

Appleply

Appleply is a product made in Oregon by States Industries. If you cannot find it locally, you can order it direct from ApplePly Hardwood Plywood. They are sometimes out of stock in the sheet size you want, but it may be available in other sizes. I buy the 4′ x 4′ sheets. If you do, I recommend you buy it in groups of four to get the most out of your shipping dollar. They ship them UPS in a big box with up to four sheets in one box. A nice protector sheet of packing material is between each plywood sheet, and edge protectors of thick hardened cardboard do a great job. I have ordered from them twice and have not been disappointed.

Appleply is made with inner layers of birch or alder. They have various options to choose from for the face veneer. I usually pick cherry, but I recently included a sheet of their white maple. There are a lot of maple species, but since they are located in the Pacific Northwest, I am going to assume they are using Bigleaf maple. I am also assuming the inner layers are rotary cut with the face layers plain cut. Some of the cherry I have has beautiful book matching grain. Here are the Wood Database pages for the new species introduced.

• Red Alder | The Wood Database
• Bigleaf maple | The Wood Database

You can see this wood has four inner veneers with two fairly thin face veneers.

Cabinet shop off-cuts

Cabinet grade plywood – There is a cabinet shop located nearby that makes and sells high quality cabinets to a nationwide market. They used to have an outlet store where you could obtain pallets full of scraps and quality reject wood pieces. By this I mean they would cut a drawer front, and if there was a small splinter it would be rejected. You might have a 6″ x 24″ of 3/4″ thick maple that was in good shape except for a little nick on one corner. I frequented this place quite often, as the wood projects I make are often of a smaller size. One time, I was able to pick up a pallet of sheet goods at a price that I still cannot believe. The 1/2″ thick panels are 2′ x 2′, and the 1/4″ panels are 16″ x 18″. The face veneers are maple, and I assume the inner layers are birch or alder. The 1/2″ sample has seven inner plies and two face veneers. The 1/4″ sample has three inner plies and two face veneers.

The stacks are considerably shorter than they were, but you can see there is quite a bit of plywood there. As an added bonus, they are finished on the good side with some sort of varnish or lacquer. I thought I was going to make unique puzzles from this, but the 1/2″ material is really too thick. I have sold a few, and exchanged some at a Puzzle Parley, but that is all. The 1/4″ plywood is quality wood but is not as good for puzzle making as Baltic birch and Appleply. I use scraps of it for practicing different or new puzzle piece styles. I will include one blank of each of this stuff in my little comparison project.

MDF core panels – included in the same pallet were some thinner panels that have an MDF core and face veneers of maple and alder. These are nominally about 3/16″. I have not used these for puzzles before but will include some in this test. If you look at the upper right-hand corner, you can see what happens if you sand this thin face veneer too long!

Miscellaneous scraps

Poking around through my scrap pile, I found some other pieces of material to use for this comparison test. I may not even cut these, depending on how done with the project I am by the time I get to them!

Construction grade plywood – This is a piece of 1/4″ construction grade plywood, like I made my first puzzles with. It has three layers of veneer made from some flavor of evergreen tree, like Douglas Fir or spruce or something.

Solid maple hardwood – This is actually a piece of a panel I made from 8/4 hardwood maple I resawed on my bandsaw. The maple was originally a scrap from making a poster bed for my daughter 30 years ago. This maple came from Steve Wall Lumber Co. in North Carolina. I bought it when we lived in Georgia and have been carrying the scraps around since then.

Masonite (hardboard) – I really searched for some solid hardboard to test as a puzzle. I did not find any. However, I did find a small piece of pegboard which is the same stuff with holes in it. Now, can I make a presentable puzzle from a piece of pegboard? I have no idea, but we might find out! The one drawback is that this is not 1/4″ hardboard, but rather 1/8″.

Cutting preparation

All of these samples (except the pegboard) were sanded on both sides (except any pre-finished sides were not sanded) up through 320 grit. The thickness of each sample was measured with a dial caliper both before sanding and after sanding. Each sanded panel was weighed. The results of the measurements can be seen in the below table. The red measurements are common measurements to use as reference to compare the various wood thicknesses to.

Please note that many woods are sold as a nominal measurement. In other words, a lot of material sold as 1/4″ is not actually 1/4″ thick. It is often 1/32″ thinner. So, if someone sells you a puzzle that is made of 1/4″ material, and you measure it and it is only 7/32″ thick, they were not lying to you. They told you the nominal thickness of the material. Another example of this would be if you go to the big box store and buy a 2 x 4 stud, you might think it will be 2″ thick and 4″ wide. No, that was the rough-cut measurement as it came out of the saws. Once it comes out of the saw, it is run through the planer to remove all the rough material and splinters. When it settles in the stack at the box store, it is nominally 1 1/2″ thick and 3 3/4″ wide. Note that is still a nominal measurement. Wood shrinks and swells, different sawing/planing machinery is set to different tolerances, etc.

So, that wraps this segment up. Now to take some time and go cut puzzles!

Happy Puzzling!

Bob

There are many possible materials to use for a good jigsaw puzzle. It is not always a form of wood, either. There are numerous examples of puzzles made from materials such as acrylic, thin metal, etc. Someone has recently made a Facebook post showing they cut a puzzle out of a sheet of embossed leather. I have even heard a rumor that cardboard puzzles exist! Gasp! Perish the thought!

In general, though, some form of wood is most commonly used as a base for a good puzzle with a positive tactile feeling. I am going to examine some of the options available, but certainly not all of them. As always with my posts, these are my results based on my personal experience, preferences, and prejudices. There is no one right answer. (And, my experiences are based on materials available in the U.S., other materials may be easier to find overseas.)

In the past, I have mainly used Baltic birch plywood when I make puzzles. I have not always been happy with the results with respect to how the wood performs. Baltic birch is good in that it is stable and strong. Recently, I have started using a product called Appleply with a cherry veneer on it. This is made by States Industries in Oregon. I like it better than Baltic birch. That is one of my prejudices I mentioned. I have been a woodworker since my age was in the single digits. My favorite wood is cherry, so I am always going to lean towards anything made of cherry.

But it may not be the best wood available for making puzzles. I have acquired a number of different samples of various sheet goods that I am going to use to make puzzles out of.

Before I start, maybe a little basic background.

Solid wood

This is exactly what it says. A piece of solid wood that is thin enough to make a puzzle with. A woodworker can take a slab of some wood, say maple, rip it to thin slices using a bandsaw, glue those sliced sections together at the edges, and make a wide and thin panel of solid wood. Solid wood presents some issues for the puzzle maker.

• may be subject to warping with moisture changes
• not strong enough across the grain – puzzle pieces might break easily
• may be expensive as compared to some other material
• time consuming to make panels big enough for a puzzle

Plywood

Plywood is an engineered material made from thin sheets of solid wood. The sheet thickness varies based on the intended use of the plywood. The thin sheets (called veneers or plies) are alternated by 90 degrees and stacked together with glue until the desired overall thickness is achieved. This eliminates the first two bullets above for solid wood. The inner layers of veneer are usually made from an inexpensive wood source. The outer layers (face veneers) are often made from a wood source valued for its appearance. Using thin veneers of expensive wood for the face veneers offsets the third bullet point above for solid wood.

Plywood can be broken down into so many different categories that it could fill a book to write about them all. The two most basic categories are construction grade and cabinet grade (or furniture grade). Construction grade plywood is made from softwood, often has thicker layers of veneer, and is full of knots and filled or unfilled voids. The 1/4″ thick stuff has 3 layers with no face veneer to it. It is ugly. Not what we want to use for a puzzle, but is actually what I started with when I first made puzzles for my grandmother.

Cabinet grade plywood is made from thinner layers of hardwood veneer. The inner layers are often made from rotary cut birch, poplar or aspen. The face veneer is often made from plain sliced hardwoods such as cherry, oak, walnut, etc.

This on-line article from Wood magazine explains the difference between rotary cut and plain sliced. What veneer patterns are available for plywood? | Wood (woodmagazine.com)

This is an interesting video on cutting rotary veneer in a modern plywood factory. Plywood Machinery | Veneer Rotary Line – YouTube

This one is from a more man-power intensive time. Manufacturing plywood boards

Cabinet grade plywood will have at least one very nice surface to it. The opposite surface may be of a lower appearance quality. The interior plies may have voids in them. Most lumber stores are going to have some inventory of cabinet grade plywood in stock. Here is an image of a piece of 1/4″ maple plywood showing a void. You can see it has three inner layers with two very thin layers of face veneer. The inner layers are probably birch, and the outer layers are maple. DO NOT sand too vigorously, or you will not have a face veneer left to look at.

That void is not something you want to discover while cutting a delicate puzzle piece. You can, of course, fill it with an appropriate filler material, but that is extra work you really do not want to need to do. That brings us to the good stuff!

Multi-ply

Multi-ply encompasses a short list of very high-quality plywood products: Baltic Birch, Finnish Birch, Russian Birch, Europly, and Appleply. There may be others. Baltic Birch is usually fairly easy to find locally, the others not so much. These products have much thinner veneer layers and are supposedly void free. (I will state that I have had to discard several pieces of Baltic Birch that DID have voids in it. It wasn’t just one or two. It was like working with Swiss cheese.) These are more expensive than the cabinet grade plywoods, but for puzzle making are worth the extra cost. Here is an image showing construction grade, cabinet grade, Baltic Birch, and Appleply for comparison.

The top piece is construction grade plywood, made of three plies of a softwood such as Douglass Fir. Next, is the same piece of cabinet grade plywood we saw previously, showing three layers of an inexpensive hardwood such as birch or poplar, with two very thin layers of maple as the outer veneers. The third item is Baltic Birch. It has five equally thick layers of birch. The bottom piece is Appleply, which has four inner layers of birch and two thinner outer layers of cherry (bottom layer is hard to see here).

Fiberboards

Here is where another one of my prejudices will be evident. I do not like fiberboard (fuzz wood, particle board, etc.) in most circumstances. It is heavier than real wood, it creates nasty dust, it does not do well with moisture, does not hold fasteners well, and typically is not as strong as the equivalent sized plywood.

However, it does have some advantages. If you have ever painted a piece of wood, you realize that the wood grain shows through the paint. Some of the fiberboard sheet goods are perfect if you want to paint your product. Additionally, many of the fiberboard materials are perfectly smooth and flat and remain so as long as properly supported.

There are a lot of varieties of fiberboard available. Some are purely for construction projects and would be totally inappropriate for a puzzle. One example would be OSB (Oriented Strand Board). Another would be particle board. I think particle board in a 1/4″ thickness would just essentially crumble if cut into puzzle pieces.

Medium Density Fiberboard (MDF) – This is made from very fine pieces of wood fiber that are mixed with a resin and formed into sheets under intense pressure. There are no voids, and it is almost perfectly flat. Very easy to paint with no wood grain showing through. I have not used this for a puzzle, but others do. I do not have a piece of this and am not going to go buy a 4′ x 8′ sheet just to make a small 8″ x 8″ test puzzle.

Medium Density Overlay (MDO) – This material has great potential in my eyes. It has a wooden veneer core like the plywoods above, but the outer face layers are made of MDF. This gives the strength and resilience of plywood, with the paintability of MDF. A lot of outdoor signage is made from this material. Unfortunately, I have not been able to lay my hands on a sample.

Melamine – this has a particle board core but has face veneers made of a plastic resin like material. I would avoid this. Particle board is not particularly strong, and the plastic resin face veneers chip very easily and eat circular saw blades like crazy. I cannot image scroll saw blades doing well with this.

Hardboard (Masonite) – This is also made from fine pieces of wood fiber mixed with resin. Unlike most fiberboard, it is somewhat flexible when still in the large sheet size. This is what pegboard is made of but is available in solid sheets without all the holes in it. It comes in 1/8″ and 1/4″ thicknesses. I used to have some for making patterns that I wanted to repeat, such as for tracing out Queen Anne furniture legs to cut on the band saw. If I can find a piece in my scrap pile, I will add it to the sample list. It can be brittle, so maybe not a good puzzle material. Might be a good choice for painting pieces, though. Some of the laser cut puzzles I have acquired seem to be made with this material or something very similar.

MDF core – This is a product that has a core of MDF but is covered with face veneer of wood. I have some of this in maple and alder. I have never used it for a puzzle, but I will cut a test puzzle from it.

This link leads to a good summary of all the above and more. Woodcraft Magazine

Well, this is a long post. I think I am going to be into another three-part post series here. My next one will be details about the samples I am going to cut, and then the third one will be about the discoveries made while cutting them.

Happy Puzzling!

Bob

Well, I thought I was done writing about scroll saws. I really had nothing else to say, unless I was presented with an opportunity to use someone else’s saw to cut a similar puzzle. However, I received a couple of comments about blade movement that I ended up delving farther into. These comments were about how the Pegas and similar saws can be adjusted to make blade movement almost go away.

That really troubled me, as the geometry of the short arms moving through an arc is going to make for more blade movement fore and aft on the saw than the longer arms of the parallel arm saws. I found this video by Steve Good of the Scrollsaw Workshop. It is a good video about the DeWalt specifically and worth watching.

So, I decided to measure the amount of actual movement of my own DeWalt saw. I have a set up gauge with a magnetic mount. I placed a small steel rule in the blade clamps to ensure that any flexing of the blade did not contaminate the results.

Next, I used a screwdriver to manually turn the saw motor to slowly move the pivot arms.

Next, I moved the motor to one extreme of blade movement, and zeroed out the gauge.

Then, I rotated the motor to determine the maximum amount of blade deflection.

.036″ of an inch blade movement! Wow! That is basically double the theoretical .018″ I previously calculated. That calculation was based on the assumption that the arc motion of the blade started out at 0 degrees deflection and was split evenly up and down from that point. It turns out that is the best-case scenario. What if the blade starts out at 0 degrees deflection and the entire movement is either up or down? Time to get out the calculator again.

Now, using my previous calculations, we have a range of back-and-forth motion of the blade from best case to worst case.

DeWalt is from .018″ to .073″. Mine measured at .036″.

Hawk G426 is from .005″ to .020″. Mine measured at .009″.

Shopsmith is from .006″ to .022″. Did not get measured.

You can see the best-case scenario for the DeWalt is basically equivalent to the worst-case scenario for either the Hawk or the Shopsmith.

In the previously referenced video by Steve Good, at about time mark 3:21, he discusses adjusting the motor on the Seyco saw to minimize this movement. He mentions that the adjustment raises the upper arm (or conversely, lowers it). At about time mark 4:27, he comments that the Type 1 DeWalt’s seemed to have better manufacturing tolerances than the Type 2 DeWalt’s and generally have less blade motion. I have no personal experience with this, so take it for what it is worth.

In this other video, Steve Good reviews a pre-production version of the Pegas scroll saw. At about time mark 6:31, he starts discussing adjustment of the fore to back blade movement on that brand of saw. Notice there are two different adjustments that can be made.

I do not have an adjustable version of these saws. However, it appears to me the adjustment just allows you to move from the high end of the range to the low end of the range. The geometry of the movement of the short arms of the double parallel link system is still going to result in more blade movement than the longer arms of a parallel arm scroll saw.

Does this mean one is better than the other? No, not at all. It depends on what you are looking for and at what cost. The DeWalt is a great saw and I have been using mine for years and been happy with it. Now that I know about the issue, though, it is probably going to bug me! I wish I could adjust it down to the lower end of the range. For the most part, the DeWalt may remain my go-to saw for most of my puzzle cutting. The blade changes are faster, and it cuts faster because it cuts more aggressively. However, for some pieces, the Hawk will be the go-to saw. The Dragon Tail pieces are much easier to cut on the Hawk. My frog signature piece can be challenging to cut with the DeWalt blade jumping around like it does. For example, look at the picture below:

If you look at the right leg where it meets the body, that gouge is from the blade jumping back and forth as I spin the wood around the blade, trying to get a nice clean point. Compare that to the picture below, which is almost perfect.

This was also cut on the DeWalt, but the blade speed was dialed waaay down to give me more time to spin the wood.

Once I figure out how to resolve the MGT reverse tooth blade issue on the Hawk, it may become my preferred saw. All three of these saws are perfectly fine saws for cutting. Each fulfills a different need. I have a pickup truck for hauling loads, a Tahoe for hauling people, and a convertible sporty car for hauling @$& and having fun! And, I have a DeWalt for fast simple cutting and a Hawk for very detailed cutting!

At the time of this writing, there is one Dragon Tails puzzle listed on Etsy. This puzzle was cut in the testing of the three saws. FiveFrogsWoodworking – Etsy

Happy Puzzling!

Bob

This last installment will be a discussion of my observations as I cut three very similar Dragon Tail puzzles, one with each of the three saws I have discussed before.

For all three puzzles, I started with a 9″ x 9″ piece of cherry 1/4″ Appleply plywood. Using the cherry was kind of a waste, as I ended up painting both sides of these. I actually cut a fourth puzzle at the same time for a customer, and she wanted hers painted on both sides to make the puzzle harder to solve. I just went with it for all of them to keep it simple.

The finished size of each of these is roughly 9 1/4″ x 9 1/4″. To keep the conditions the same, I used the same blades on all three puzzles. The blades I used are Pegas MGT 2/0R blades. I have used these for quite a while. They are only .0087″ thick, .0236″ wide, have 15.4 teeth per inch (TPI), and the bottom 10 teeth point up. They give a very smooth cut with the DeWalt saw. The reverse section of teeth gives a smoother cut on the bottom, especially important if I am cutting a double-sided puzzle with an image on the bottom as I cut. My previous favorite blade was the Flying Dutchman Special Puzzle blade from Mike’s Workshop, but I have found these Pegas blades are just a tad better for what I do.

To prepare each saw, I cleaned and waxed the table before I started. I wipe down the table with either denatured alcohol or mineral spirits to remove any greases or oils that may have landed on the table. If a cast iron table has a little surface rust, I will first use a very fine grit sandpaper (1200 grit or finer) to remove rust. Once the table is clean, then I apply wax to protect the surface from oxidation and make the wood slide nice and easy.

You need to make sure the wax used does not have any silicon in it, as silicon will interfere with any finish applied later. And you need to ensure it does not have any traction additives. Some floor waxes have a friction additive to prevent slips and falls. That is not what we want for this. I have previously used Rhodes Furniture Paste Wax and Johnson original formula paste wax. I am currently using Butcher’s Bowling Alley Wax. There is no magic to the brand, just a good paste wax with no silicon and no friction additives. Every home should have a tub of good paste wax around. It is good for protecting metal surfaces, polishing wood furniture, polishing leather, lubricating wooden window frames, lubricating stubborn drawer slides, and just a dab on the tip of a wood screw will help it go right in with less chance of splitting the wood.

As an aside, I discovered tonight that Johnson Paste Wax was discontinued. That stuff has been a staple for longer than I have been alive. Like one gentleman on a forum said: “For someone of my generation, finding out that Johnson’s Paste Wax was discontinued is like going into an auto parts store and being told WD-40 was out of production, or going into the grocery store and finding out they’d stopped selling Cheerios. It just a product that’s part of Americana for us Baby Boomers.” I also discovered that Butcher’s Bowling Alley Wax is gone as well! Fortunately, another company acquired the rights to the Butcher’s recipe and are making and selling the product as “Bowling Alley Wax”.

Whatever brand you have, smear some on the tabletop and let it set for 5 minutes. It will get kind of hazy in appearance and hard. Then you just buff it off until the tabletop is nice and slick and shiny.

Next, I like to start each project with a new blade. They are about .25 each when you buy a gross of them, so it is not a huge investment to start with a new blade. Install the new blade and adjust for proper tension by plucking the blade with your fingernail. This link is a short video from Judy Gale Roberts on how to listen to your blade for correct tension.

Finally, I verify the tabletop is square to the blade side to side. Instead of messing around with a little square, I grab a thicker piece of wood and then start a cut into it. Once the cut is started, I back the wood off of the blade and turn off the saw.

Without lifting the wood off of the tabletop, I spin the wood 180 degrees around the blade and line up behind the blade with the slot I just cut. If it looks like this below where the blade is not parallel to the saw kerf, you need to split the difference to level the tabletop.

Once the tabletop is properly adjusted, the blade will be parallel to the kerf and slide right in the slot! You are ready to start cutting. The picture below looks wrong because the camera was a little to the side and caused some parallax in the view, but it is nice and square.

I started cutting with the DeWalt saw first. This is going to be my baseline to compare the other two saws to. This has been my go-to saw for years and the one I am most comfortable with going in to this. Cutting with this saw is “comfortable like an old shoe”. I really do not have much to comment on at this point other than I like having the controls all in one place on the top of the upper mechanism.

I am used to cutting with my workbench on my left side, and with a rolling table on my right side. To keep the cutting experience consistent, I moved each saw into that position when I used it to cut this puzzle. In the picture below, the yellow DeWalt is in that position. When I was done with the DeWalt, I pulled it out of the way and moved the Hawk there. That also made it so the magnifier light was available without much difficulty. If you look on the floor, you can see the residue from cutting the edge of the first puzzle.

I am not going to give a blow by blow of cutting with each saw. I did not take any video as I was doing it, either. I am just going to give numbered bullet type findings. The first step on all three was to cut the edge.

The blanks were slightly cupped. This made cutting a little challenging as the board rocked. To reduce this effect, I cut them in half with dragon tails along the center of the cup line. Here is a picture of the one cut using the Shopsmith saw.

And one cut in half. The panels were cupped with the centerline of the cup along the path I cut, so the right and left sides were a little bent up. Doing this made them more manageable during the cutting process. One these were finished, the little bit of cupping was gone and will not be noticed by anyone assembling them.

Now for my observations.

Observation #1 – Detailed cutting control. It is funny how you do not know if there is a difference until you discover it! I did not know I was near-sighted and needed glasses until I went in the Navy. Now that I wear glasses all the time, I feel blind without them. In this case, I discovered I had much more control cutting the curly tips of the dragon tails with both the Hawk and the Shopsmith. Cutting those with the DeWalt was actually a little hairy. I was turning down the saw speed just to maintain control, especially with a new blade. I realize that is how I normally cut with the DeWalt, constantly adjusting speed depending on what I am cutting and how dull the blade is getting. With the Hawk and the Shopsmith, I did not adjust the speed dial for the entire puzzle. A little geometry review explains this issue.

Remember back in Part 1 when I discussed the parallel link saw system and I mentioned it moved the blade fore and aft more than a parallel arm system? The short arms of the parallel link have to move through a greater angular distance to achieve the same saw stroke length. Let’s start with the length of the arms in discussion. I measured from the pivot point of the arm to the blade. Here is a combined picture of the three measurements.

Pivot arm length for the DeWalt is 3 7/8″ (3.875″), the Hawk is 19 1/8″ (19.125″), and the Shopsmith is 17 5/16″ (17.3125″).

Now we need to know the stroke length for each. From the manufacturer brochures, the DeWalt stroke is 3/4″ (.75″), and the Hawk and Shopsmith strokes are both 7/8″ (.875″). Assume when the arm is level, one half of the stroke goes above level and one half below.

Now we use the Pythagorean Formula: a² + b² = c² . Here’s a drawing with some math.

What does all this mean? When you are sitting at the DeWalt, the saw blade is moving towards you and away from you by .018″ every stroke it takes. That does not sound like much movement, but remember the blade itself is only .0236″. The blade is moving almost the entire width of the blade. The Hawk and the Shopsmith have one third less blade movement. This effect was VERY noticeable as I was cutting the tips of the dragon tails. Does this mean the DeWalt is no good? Heck no! Remember, I was unconsciously compensating by slowing down the stroke speed to maintain control of what the blade was doing. Until I cut on the Hawk/Shopsmith, I did not know any different. Now I do!

Observation #2 – Use of reverse tooth blades. This one totally flabbergasted me. As I was cutting the puzzle with the Hawk, I noticed that the top of the puzzle was getting whiskers on it along the saw kerf. I am used to having a minimal amount of these on the bottom of the wood, and none on the top. The same thing happened with the Shopsmith, but not as pronounced as the Hawk. There are two factors causing this. The first one is the actual design of the saws. I measured the distance from the table up to the bottom of the upper blade clamp while the saw was at the top of its stroke. The DeWalt measured at 3.125″, the Shopsmith at 3.25″, and the Hawk at 3.375″.

So the Hawk design geometry keeps 1/4″ more of the blade over the table than the DeWalt does. Here is a picture of what that looks like with my preferred blade installed. Each graduation on the rule is 1/16″. You can see at the 1/2″ mark where the transition from reverse tooth to normal tooth blades happens. If cutting with 1/4″ plywood, a full 1/4″ of reverse tooth blades protrude above the surface. Not a problem with this particular puzzle, as a quick sanding at the end removes them all, but it does impact it if there is an image attached.

This was the biggest and most impactful revelation that happened to me from this comparison cut. I was totally unaware of this and it has impacted one of my puzzles. If you have read my prior blog entires, you saw a multi-panel puzzle I made of a fall oak leaf. I cut a 13 x 19 panel down for ease of handling using the Hawk scroll saw, and I noticed that cut line appeared to be more prominent. I blamed a bad blade, but now I know it was the effect of using reverse tooth blades on the Hawk scroll saw. You can see that one cut line stands out a little more than its neighbors in the picture below.

For the Shopsmith, the amount of reverse blade above the table is 3/8″, or 1/8″ above the plywood.

For the DeWalt, a little over 5/16″ above the table, or 1/16″ above the plywood.

I said there were two factors that affect this issue. The second one is the blade holders themselves. You may remember that I mentioned in Part 2 that the blades have to be fully inserted in the blade clamps for the Hawk and Shopsmith in order to maintain a constant tension with blade changes. There is no adjustability of where the blade rides with respect to the table. On the DeWalt, however, the blade clamps are slots. You can move the blade up and down in the slots just as long as the blade is fully engaged top and bottom.

So you can see that by adjusting where the blade is located, you can affect the number of reverse teeth in the wood.

If I am going to use the Hawk for cutting puzzles with images on them, I will have to find a new blade to use or make an auxiliary table that will raise the puzzle up so the reverse tooth blades do not protrude above the image side.

Observation #3 – Noise as it runs. The DeWalt was noticeably quieter than the other two. The Hawk and the Shopsmith were about the same. I will note that the Shopsmith attachment on the Shopsmith headstock is very loud. Not part of this cutting test, but worth mentioning.

Observation #4 – Shopsmith blade clamps. These turned out to be very annoying as compared to the other two machines. The end of the screwed studs on the Shopsmith were tapered. That means there is less flat surface to engage the blade. If the blade was not perfectly centered on the studs, it would tend to slip out. Now, if you have a lot of blade slipping problems, you are supposed to clean and degrease the studs. If they are highly polished from a lot of use, then you take some sandpaper and roughen them up. In this case, they held fine when perfectly centered.

Observation #5 – Blade breakage. The only saw I broke a blade on was the Shopsmith. I actually broke three blades, which is indicative of the tension being too high. The tension being too high might have also been a factor on my issue with the tapered studs in the blade holders. The real problem with broken blades with the Shopsmith is that the upper arm beats the stuffing out of the cover over the upper arm. It makes a lot of noise that startles the cutter half to death. Neither of the other saws did anything like this. I have broken blades with them before, and you just calmly reach and turn the saw off. With the Shopsmith, it sounds like the saw is going to explode. It actually shattered a clear plastic guard that I will have to replace before I return the saw to my daughter.

The rest of my observations are really minor issues and preferences.

I like the articulated airline to be on the left side of the saw like it is on the DeWalt. The Hawk gives the ability to move it, so I am going to do so. The Shopsmith airline is a metal tube that is integral to the hold down foot. That sucks! Besides having the hold down foot in the way, it blows the dust straight at you. This issue almost had me finish this puzzle using one of the other saws. As mentioned in Part 2, I will be upgrading the Shopsmith with an articulated airline before I return it to my daughter. With the articulated airline, she can remove the foot and this major annoyance would be fixed!

I really like the cast iron table on the DeWalt over the aluminum tables on the other two. I cannot put a hard reason for it, I just like the cast iron.

The sides of the cuts on all three saws were very smooth.

Summary. All three saws are perfectly adequate to cut a nice puzzle. As with many things in life, each is a compromise. I really like the ease of use of the DeWalt. Having the three major controls up top is a huge benefit, and the blade changes with it are the fastest of the three. It works well with the blades I like. The Hawk has a plus in the greater throat depth (26″ vs 20″) and the minimal movement of the blade back and forth. The Hawk also has some interesting features that were not germane to this test. The Hawk has a greater thickness it can cut. I guess if I had to pick one to “let go”, it would be the Shopsmith. Fortunately, that is the one that I can take back to my daughter’s house! Having said that, the Shopsmith is perfectly adequate and up to the challenge. It does need the airline upgrade.

When I look at the puzzle cutting statistics, the DeWalt cut 15 more pieces in 20 minutes less time than the Hawk. Some of this might be because I was flopping around about the rough cut on top, but I stopped logging my time while I was researching that issue. The DeWalt is just lightning fast on the blade changes. The Shopsmith statistics are not shabby either.

I would not hesitate to buy any of these saws used if they are in working order and at the right price. If I was forced to buy one of these brand-new, it would probably be the DeWalt based on the price point. I personally think the Hawk is a better made saw, but it is considerably more money.

Which saw will I use going forward? I will be working on a custom order puzzle soon, and it will be with the DeWalt. I need to figure out how to resolve the blade issue with the Hawk before it gets much use.

Now if only someone in the Spokane or Coeur d’Alene area had a Hegner or Pegas I could borrow to add to the comparison!!

Of the three puzzles pictured above, two are already sold! The third one will be listed on Etsy in a couple of days and will remain there until it is sold.

Happy Puzzling!

Bob

Before I start, a couple of comments on the last post. #1 – if you have a scroll saw with pinned blades, I was not trying to run it down. I was pointing out issues with pinned blades for those who are looking at buying their first saw so they can maybe make a better-informed decision BEFORE they buy one. #2 – I mentioned a constant tension rigid arm saw called the Eclipse. There were not very many made before the company closed its doors. If you look at this news clip, you can see where a number of them went: www.wcvb.com/article/norwich-vermont-puzzling-and-perplexing/10286694 . If you go to about 1:45 in the video and pause it, you can see a lineup of at least four of them at the Staves workshop! If they have four, they probably have more. That tells you something about the desirability of these saws for the quality of the work they turn out. And, they are being heavily used in a commercial shop, so they must have good durability.

For this blog post, I am going to discuss the basic characteristics of the three saws I have and one I once had. These saws are a Sears Rigid Arm Saw, a Shopsmith (20″), a DeWalt (20″), and a Hawk (26″). At the end of the post is a comparison table that lists the specifications side by side.

Sears Rigid Arm Saw – I no longer have this saw and it did not get used to cut a puzzle for this blog. I thought some comments would be useful, though.

The saw was heavy. It was made of cast iron, which I kind of liked. The table was small, maybe 10″ by 10″. It did NOT use pinned blades. I remembered this morning that it had blade clamps that were tightened with a hex head allen wrench. I had a tether on the allen wrench so it would not get lost and it hung down below the table until I needed it. For the most part, it worked really well using the larger sizes of scroll saw blades. The stand it was on was home made out of pine 2×4’s, which was not ideal. The only real problems came up when I started getting interested in cutting puzzles and tried using the smaller puzzle blades. Mine might have been deficient as compared to some others, but maybe not. There is a reason the “constant tension” aspect of the other saw mechanisms is emphasized.

Because of the spring return and subsequent variable tension, you cannot run these saws at a high speed. So, they go straight up and down, and cut slowly. There probably is not a better combination for doing very detailed and accurate cutting, or for learning how to use the saw. Speaking of speed, mine had a belt with 3 or 4 position pulleys to vary the speed. Some others I have seen have a mechanism with a crank to vary the speed with.

An interesting feature of many of this type of saw is that the rigid arm can be removed, and a stiff sabre saw blade mounted in the lower blade clamp. You now have a table with a saw blade sticking up out of it and you can cut as big of a piece of wood as you and your helpers can handle. I knew a fellow that did this and cut up some sheets of plywood into those large Christmas yard decorations that are profiles of a bunch of reindeer with Santa. The wife and kids helped him paint them as a family project. Personally, I would have gone and bought a handheld jigsaw (aka sabre saw). It is a lot easier (and safer) to handle and spin around a handheld saw to cut reindeer antlers than to manipulate a 4′ x 8′ sheet of plywood. But to each their own.

I often see Rockwood-Delta rigid arm scroll saws listed on Craigslist fairly inexpensively. I just checked my local listings, and there are three of them that pop up. One looks like a rusty piece of junk, the other two might be in good shape. If you are starting out and do not have a bunch of money to throw at a saw, you might want to go check out something similar to one of these. If it works well and is cheap enough (under $150 maybe), it may be a great starter saw. Just be aware, it may not work well for cutting puzzles. Go to your local store and buy some 2/0 size scroll saw blades. Take them and a small piece of 1/4″ plywood with you and ask to run the saw. Install your new blade and try to cut some puzzle pieces. If you cannot get it to work without breaking blades, or if they will not let you test it, walk away. (This applies to any used scroll saw you buy. I have done this with my last two. I got some funny looks, but why buy something that does not work?) You would probably need to be a little mechanically inclined if you are buying an older saw like that. If I did not have a saw and not much money to buy a better saw, I think I would rather work with one of these in good working order than a new one of the inexpensive light duty benchtop models sold through places like Harbor Freight and the like. Neither option is particularly desirable, in my opinion, but we do what we can with what we have.

Shopsmith scroll saw attachment.

The basic Shopsmith is a five-in-one tool that includes a lathe, table saw, drill press, 12″ sanding disc, and a horizontal boring tool. You can buy additional attachments that can be powered by the same motor (headstock) using a connector piece. The available attachments for purchase have at various times included a jointer, a planer, a belt sander, a strip sander, an air compressor, a paint sprayer, a grinding wheel, a bandsaw, a biscuit cutter, router collets, sanding drums, and, yes, a scroll saw. And, before the constant tension parallel arm scroll saw, there was a rigid arm scroll saw.

These do not get much respect outside of the adherents of the system. Because I was in the Navy and moving a lot, I could not acquire a lot of woodworking tools. I would have loved a big Powermatic table saw and a sanding station and …. . Fill in the dream shop tools of choice. We moved 13 times in 20 years, and only had so much weight allowance the Navy would pay to move. I bought into the Shopsmith paradigm and have never really regretted it. I have made a couple of poster beds, quilt racks, and lots of other stuff using mine. I took up bowl and pen turning for a while but never really did enough to be good at it. Two winters ago, I had a contract to make 50+ small bulletin boards for a senior living facility. The Shopsmith works great for many woodworking chores. I currently have two Shopsmith’s of different vintages. In the picture below, I am holding a bulletin board on one that is set up as a table saw, and in the background you can see a green one that is set up with the belt sander mounted on it.

I was not specifically looking for a Shopsmith scroll saw attachment, but I was looking for a used scroll saw to supplement or replace the Sears rigid arm saw. I really wanted to cut puzzles and the Craftsman rigid arm saw wasn’t cutting it. This was before Craigslist was a thing, so I was perusing the recent weekly Uncle Henry’s booklet (a revered Maine fixture similar to the Nickel Nick or Thrifty Nickel found everywhere else I have lived) and found a listing for a Shopsmith scroll saw attachment. “Oh, wow! Perfect!” I called and the fellow still had it and would I pleeaaassseee come look at it. It had been listed for a couple of months, and his wife was eager for it to be gone. It sounded like a ripe opportunity for me and my wallet! I verified it was one of the newer style parallel arm saws and not the old-style rigid arm saw and off I went.

It turned out he had a wood shop in an unfinished area above the garage. He had orders to clear it out to make an apartment for his mother-in-law. As we were dickering over the scroll saw, he pointed at a radial arm saw and offered it to me cheap as well. I said “no, thanks, I am not a fan of radial arm saws.” He finally said he would sell it to me for $50 so he could tell his wife he got money for it. Then, he would pay me $50 to help him move it down the stairs! For $150 total, I brought home a nearly new radial arm saw, the Shopsmith scroll saw attachment, a router, and some other stuff. I asked him how he was going to turn the space into a mother-in-law apartment after selling off all his tools. He got a really hang-dog look on his face and said he wasn’t allowed to; they were going to hire a contractor so it would not take 5 years to happen. Poor guy.

The scroll saw is made of some sort of aluminum alloy casting. It is designed to be picked up and mounted on the Shopsmith, so it needs to be light and portable. Per the owner’s manual, it weighs 32 pounds.

It mounts on the left side of the motor unit. The accessory drops into machined cylinders on the base unit, and then a plastic connector rod runs between the accessory and the motor unit. See picture below. The five grooved knob on the left is on the accessory, the white plastic thing in the middle is the drive link, and the upper four grooved knob is connected to the motor.

When it is all put together, it looks like the connection on this belt sander below.

Shopsmith was pretty proud of these and wanted a premium price for them to buy a new one. They also sold other options for using your scroll saw accessory. You could buy a “Power Stand” that the accessory permanently mounted to. This included a motor, belt, and everything else needed to turn the accessory into a standalone tool.

You could buy a “Power Station” that you mounted the accessory on to use it, but then take that accessory off and mount a different accessory, such as a belt sander.

Or you could even buy a standalone Shopsmith Scroll Saw from the get-go, which was completely different from the “power stand” option. They had their own stand and variable speed DC motor. I bought one of these from a Craigslist ad a few years ago and gave it to my daughter.

I bought my Shopsmith attachment around 1998 or 1999. I cut with this saw for years and am/was quite happy with it. However, I came to realize that I was putting a lot of time and wear on my expensive Shopsmith unit doing a function I could do with an inexpensive used stand-alone saw. So, I started looking in the local ads again for a different saw, and that is how I ended up with my DeWalt.

I wanted to cut a puzzle with a Shopsmith scroll saw for the comparison. I decided to borrow my daughters standalone Shopsmith scroll saw which I had given her as a gift a few years ago. It is functionally the same machine as my attachment. In fact, even the base casting is identical to mine. It has the cylinders in the bottom for placing the mounting tubes to put on the Shopsmith unit. The only real difference is that it has its own electric motor and a steel four-legged stand. The owner’s manual says it weighs 62 pounds.

Blade mounting – as originally delivered, these used blade clamps that need to be tightened with an allen wrench. This was not an uncommon system decades ago. Many saws used a blade clamp that required a separate tool.

Also, on the constant tension parallel arm saws, the distance between blade clamps HAS to be maintained as the same each and every blade change to prevent having to readjust the tension. So, you need to make sure the blade is inserted all the way to the end of the blade clamp. This is true for the Hawk saw as well.

Once the blade is mounted in the lower blade clamp, you install the clamp in the saw. If you look down through the table, you can see the retaining mechanism. You pull out the spring pin, insert the clamp, let go of the spring pin, and replace the table insert. See the below picture. With practice, you can do this quickly by feel without looking or removing the table insert. (In the middle picture of the three, below the blade clamp, you can see the dust collection intake.)

You see the long slot in the insert. This is so you can tilt the blade forward so you can insert the blade through the bottom of a piece of fretwork you are working on. Not normally needed for puzzle cutting, but good to know for other stuff. With the Shopsmith saws, you can only bottom feed because the upper arm does not lift up. Bottom feed means to insert the blade into the bottom of the work piece before placing the blade in the upper clamp. With the other saws I have, you can either bottom or top feed.

If there was a pattern on the piece of wood, I would run the saw to cut out the piece of waste material. If you are doing a large fretwork project, you would do this many hundreds of times. It has to be quick and easy to do.

Shopsmith came out with an upgrade option to do away with the allen wrench. The new blade clamps now have a thumbscrew on them. I ordered these for both saws as soon as I bought them.

You still need to fully seat the blade all the way down and all the way back in the clamp. In the picture below, you can see that even mounted all the way to the back of the clamp, the two screws firmly engage the small 2/0 sawblade. One the blade is installed, the clamp is still mounted on the saw in the same manner as before.

You can also see that with the new style clamps, there is a set screw opposite the thumbscrew. The blade is firmly clamped between the two screws. You can adjust the set screw to move the blade left or right in the clamp. This is to align the blade side to side to ensure it is perpendicular to the table. Otherwise, the blade will be slanted, and you will create a wider saw cut than the blade.

It has the largest cutting table of all three of my current saws. Picture below.

In the below picture, you can see the salient parts of the saw. The upper arm is “protected” by a cover piece. The tension adjustment knob is in the upper right. You install the blade as previously mentioned. Once the blade is installed, you adjust the tension knob. You are supposed to achieve a high “C” note when you pluck the blade.

The red knob on the left of the upper arm is to control the height of the hold down foot and air hose. I normally take these off, as the hold down foot really messes with visibility and control of what you are doing. But this is not my saw, so I left it alone. Also, the air hose is an integral part of that foot. The air hose blows the saw dust away from the blade so you can see what you are cutting. If this was my saw, I would remove all that and find an articulated airline like the other two saws have. More on those later. The box on the lower left leg is the control box. It rectifies the incoming 120-volt AC current to 85-volt DC. The round dial controls the speed of the motor. The sliding “on” switch is actually on the front, but the big red button on top is the off switch. The little red thing above the speed dial is the child safety lock control that when removed, keeps the saw from running. If you look at the legs, you can see each leg has its own adjustment to level the saw and keep it from rocking.

Under the table, you can see the tilt adjustment goes from 45 degrees left to 45 degrees right.

These shots below show the blade release lever for blade changes. The black plastic piece my hand on is that lever. You pull it forward to release the blade tension so you can remove the blade. You change out the blade and then push the black piece back into position. If you are using the same size blade as you were, the tension should still be set. If not, you can reach back to the tension adjustment knob on the top back of the saw to adjust the tension.

This is the only one of the three to show any concern about dust collection. Under the base (not the table), there is a round port to connect a shop vac up to. I have not used this, so cannot opine on its utility. My daughter has made her own adapter to fit her vacuum. In an earlier photo, you saw the top end of this fitting.

I do not believe you will find a new one of these saws to buy. The last paper catalog to list the Shopsmith accessory mounting was printed in 2018. The saw was listed then for $897.00. At that time, the power stand and standalone options were no longer offered. The 2022 paper catalog does not list any of them at all. Interestingly enough, the online catalog today still lists the accessory mounting, but shows it as currently unavailable with a price of still $897.00. It also shows the standalone scroll saw as unavailable, but with a list price of $9999.99! The 2007 catalog showed the accessory mounting as $649.00, and the standalone scroll saw as $849.00. So if the same price difference existed today, the standalone scroll saw would be around $1100.00! Perhaps they are planning to bring these back if they think the market will support them.

I do not think there is much else to say about the basic description of this saw. So, let’s move on!

DeWalt DW788.

As mentioned above, this saw was purchased to stop putting wear and tear on my base Shopsmith. I found this used off of Craigslist for around $300. It included a stand and appeared to have very low usage. I was particularly happy to find it is a Type I, which means it was made in Canada at the same Sommerville Manufacturing factory where the original Excalibur II scroll saws were made. Type II saws are made in Taiwan. I have no personal experience with a Type II.

This saw uses the parallel link mechanism. This takes you to a .pdf document on a court case that has some interesting background information on the original Excalibur saws and their relation to the DeWalt (Black and Decker) saws. In there is a mention that the original parallel link mechanism was actually patented back in 1870. I had always assumed that Tom Sommerville came up with the design, but apparently not.

Tom Sommerville was asked to design a better scroll saw than a Hegner, and the Excalibur is what he came up with. The first one went to market in January 1983. In 1988 some refinements were made. This resulted in the purple Excalibur II, which is what I think most people are familiar with when talking about the original Excalibur scroll saw. In 1995, Black and Decker approached Sommerville about making them a scroll saw with the parallel link system but a number of significant differences from the Excalibur II. The first DeWalt scroll saws started shipping in May of 1997. In 2003, General Manufacturing bought out Sommerville Manufacturing. I have read that this is when the DeWalt manufacturing moved to Taiwan and became the Type II. I find it interesting that DeWalt was labeling the Type I from the beginning. They may have been planning to move production all along.

There are differences between the Type I and the Type II, but I am not aware of them all. I can remember there were a number of forum discussions talking about some of them. One had to do with the On/Off switch getting full of sawdust and shorting out. There was an issue with warped tables and some alignment issues. Most of these all had to do with starting new production lines in a new location and were long ago corrected. The repair parts places seem to sell the same parts for both of them.

This saw is mounted on a 4-legged stand. It is sturdy enough, but it does not have individual leg levelers like the other two saws do. Most DeWalt saws I have seen have a different stand with the back leg being one wide leg instead of two independent legs. Some of the DeWalt saws are sold without a stand and can be mounted onto a bench.

Once I had the saw home and started working with it, I noticed it had a real loud knock at high speeds. Searching on the internet, I found a solution for this that worked. “If the saw has a knocking sound, that is remedied by taking the top screw out of the tension lever, removing it, then remove screws from the sides of the black housing. Be sure to go slowly and not lose the small bushing when you remove the cap. There is a rod with an L shape end that goes to the rear, with the front of the short L sticking up into the housing. After removing the metal housing piece, turn the L end of the rod one turn clockwise, and reassemble. You will notice when you tension the blade again, the tension lever won’t travel as far to the right to achieve the required tension amount, and the knocking will mostly be gone.” I have had no issues with knocking since I made this adjustment. If that doesn’t work, Rick’s Scroll saw page has several other fixes to try.

This has a different blade clamp system from the Shopsmith and Hawk saws. The blade holders are not detachable and are part of the arm assembly. There is a slot that the blade fits in, and a thumbscrew that tightens to hold the blade.

Unlike the Shopsmith and the Hawk, you can slide the blade up and down anywhere in the slot as long as the blade is totally engaged by both the upper and lower clamps. This will become an interesting point in the next blog post.

To install the blade, I pinch it between my left thumb and pointer finger. I insert the bottom through the slot in the table. Using my right hand below the table, I ensure the lower end of the blade goes in the lower clamp. Then I move my right hand up to the upper end of the blade, ensure it is in the slot and tighten the upper clamp. Then I reach below the table and tighten the lower clamp. Rotate the tension lever at the front of the upper assembly, and you are ready to cut! Push the “on” button with the same arm motion, and you are cutting. This is intuitively the fastest blade change system I am familiar with.

The table is made of cast iron, which I prefer. Cast iron will rust, so you need to keep it clean and polished with wax. The aluminum tables also need to be kept clean and waxed. Additionally, if you do not, the aluminum tables will create black marks on wood.

The table does not have an extended slot for the blade to lean forward for bottom feeding, but you can either top or bottom feed for fretwork projects. The upper arm on the DeWalt does lift up. The DeWalt upper arm contains the air blower hose and has an articulated end on it so you can adjust where the air comes from and blows toward. With the Shopsmith airline mounted on the hold down foot, air blows directly at the sawyer, which is aggravating.

The saw comes with a hold down foot, but this is the first thing I took off. I was surprised I could even find it just to take a picture!

The table tilts 45 degrees left and right.

New DeWalt scroll saws are available today. Prices are all over the place on the internet. Check what you are looking at to verify if the price you see includes a stand or not. These are often packaged with a stand, a light, and sometimes a foot switch.

That is about all there is to say about this saw! Moving on.

Hawk G426.

Last but far from least is my Hawk. Like many tool companies, this one has gone through name and ownership changes throughout the years. When I was a younger man, RB Industries (or RBI) was a well-known tool manufacturer. Besides scroll saws they made a number of other woodworking tools. They had four lines of scroll saws, but the “Hawk” line was the most popular. They even made a short-lived version that would mount on a Shopsmith! I found these pictures on a woodworking forum, and this is the only reference I have found to it.

According to the original post, this was a Hawk model SS14. The 14 meant the depth of cut was 14″. The left side picture above was the listing he bought it from. You can clearly see the two vertical posts that would be used to mount it on the Shopsmith unit. In the right-side picture above, you can see he mounted a 5″ pulley where the Shopsmith plastic connector would normally go to connect to the Shopsmith motor. Oh, the rabbit trails you can go down!

Anyway, the company traces back to 1929. This next snippet of history is a paraphrase from the current company’s website. After a couple of generations of family run business with the family name, it was sold out of the family in 1972. The new owner incorporated as RB Industries in 1976. Upon that owner’s death in 2007, the business was sold to an investment company that changed the name to Hawk Wood Working Industries. This is the company whose name is on the saw I bought. This company closed the doors on the factory in 2009 and put it up for auction. The current owners, Bushton Manufacturing, purchased the company and resumed production 2 months afterwards.

This G4 saw had the latest and greatest improvements made by RBI. At that time, RBI had their “Ultra Precision Scroll Saw” in 20″ and 26″ throat capacity. The models were 220VS Ultra and 226VS Ultra. The VS stands for variable speed. Older RBI Hawks often had a stepped pulley with a belt to change speeds or were single speed. These would typically be something like a model 220-3, meaning 20″ throat and 3 speeds. And then they introduced the G4 with a bunch of improvements. This is a great video to watch about this saw and some of the stuff it does, especially for people just getting started with a scroll saw. Based on watching this other video from the Bushton Manufacturing folks, they incorporated all those G4 improvements into their new BM series Hawk scroll saw that are currently for sale.

I was really NOT looking for this saw. I had the Shopsmith scroll saw attachment and the DeWalt. I wanted a saw with a deeper throat depth for cutting larger puzzles. I was specifically looking for an Excalibur II EX30. These seem to be pretty darn rare where I live, as I have yet to find any in the local area. Lots of Hegner’s and Hawks, but not a single Sommerville made Excalibur have I found listed in 15 years. Even used on Craigslist, the Hegner’s and Hawks have premium prices on them. I eventually found this Hawk listed for an unbeatable price and moved on it a couple of years ago. 26″ is not 30″, but you play with the hand you are dealt. Prior to this comparison test, I have used it with a #9 blade to cut some flooring for “The Cave”, which is my in-house work shop. I have also used it to cut three large puzzles in half so I could better handle them on the DeWalt (which is what I really bought it for). Cut an entire puzzle with it? Nope.

Some of the unique things about this saw: 1- lower blade clamp is in front of the tilt mechanism, making it very easy to access, 2 – the lower blade clamp can be adjusted forwards or backwards to put an aggressive angle on the blade for cutting thick wood, 3 – the accessory arm has a hole for mounting magnifying lights and it can be moved to either side of the upper cutting arm, and 4 – it can be equipped with diamond blades and an optional drip tank for cutting glass and ceramic tile. There are other items as well, but these are the ones that jumped out at me after using the Shopsmith and the DeWalt.

So, to continue with the same general discussion pattern on the actual saw, let’s look at the blade holders. These are an upgraded blade holder. Pictured below is the bottom blade holder. It has a spring clip it comes out of fairly easily. It has a thumbscrew to tighten it, so no special tools required. The “gripping” end of the thumbscrew is nice and flat, instead of the tapered end the Shopsmith uses.

In the rightmost picture above, the yellow hoop is the blade tension release. This is pulled forward to release the tension for a blade change, and then pushed backward once the new blade is in place. For some reason, I initially struggled with this set of blade holders and tension system. In fact, I kind of was avoiding using this saw until I decided to do this puzzle comparison cut. As the puzzle progressed, I became much more comfortable with it and will use this saw more often.

The tension is set from the back of the saw. Referencing the three pictures below, the left photo shows the vertical tension rod and the cam lever lock. To adjust the tension, lift the lever lock, let go, and twist the tension rod. Twist the tension rod until the lever lock is at the correct clock position for the blade size you are using per the chart mounted on the saw. For a 2/0 blade, the lever lock should be at the 12:30 position. Then, press the lever lock back down as in the first picture. From that point, as long as you keep using the same blade size, you should be able to just use the tension release lever up front for blade changes. If you find you are breaking blades, come to the back and check your tension setting again.

The upper arm can be lifted, and you can do fretwork with either bottom or top feeding. It has an aluminum table with an elongated slot to lean the blade forward for bottom feeding.

The motor controls are on the side of the saw. I will have to include a picture of them another time, as I seem to have forgotten to get one and I am not going back to the shop just for that. The on/off switch clicks up and down like a light switch (instead of sliding up and down like the Shopsmith or rocking like the DeWalt). The switch actually will pull out of the housing as a child lock. The speed control is a rotary dial.

The saw came with a hold down foot like the rest, but I removed it. The saw has a nice articulated airline that is longer than the DeWalt’s. I was on the manufacturers website yesterday and discovered they have an upgraded airline that is a larger diameter to get more airflow to blow sawdust away. Perfect! I ordered that, and once it is installed, I will put this one on my daughter’s Shopsmith saw before I return it to her.

The table tilts both left and right by 45 degrees, but to get the right tilt, you have to take a couple of seconds and switch the orientation of the lower blade clamp to put the thumbscrew to the left. Left and right 45 degrees did not really seem like a big deal to me, until one of the Hawk videos above pointed out that some brands of scroll saw have the motor mounted right under the table and physically cannot tilt the table to the side with the motor. Duh! The obvious saw that comes to mind for this is Hegner.

New Hawk saws are available to purchase today from Bushton Manufacturing. They have a number of optional accessories for their saws, including leg extension kits to raise the saw, table leg kits so you can fit a chair between the front legs, drip tanks for cutting glass and ceramic tiles, and other good stuff. They are NOT inexpensive. That is why I bought used. The nice part about used Hawk saws is that the company still supports the old ones, including having all the owner’s manuals available for downloading. Not everything is available, but many things are. Reading the owner’s manual for mine, I found they used to offer an optional caster set for this saw. You would lift a handle on the front to raise the front of the saw, and it would rock back onto two casters to easily move this around the shop. During my call yesterday, I asked for this kit, but alas, the last one finally sold and there was such little demand for it they are not making more. But, critical parts to repair your old saw, you bet!!

Here is a handy chart showing the differences between the saws. The Shopsmith accessory is included for reference. I see I did not get the body material on the DeWalt, but I suspect it is some aluminum alloy. I’ll have to hit it with a magnet next time I am in the shop.

The next entry will be part three. This will cover my observations as I cut puzzles with these three saws. I learned a few things, one of somewhat significant impact to me.

Hopefully, that blog entry will not take as long as this one. I ended up doing a lot more research than I intended to, and it has been eight days since the first post.

Happy Puzzling!

Bob

I am sometimes asked “what saw should I get?” There is no simple answer to that question other than it depends. It kind of reminds me of high school days: “My Chevy truck is better than your Ford truck!” We will not even talk about Dodges. Friends don’t let friends drive a Dodge! The same thing can apply to scroll saws.

I have often thought about writing a blog article on my personal experiences with scroll saws and am finally going to do it! I am not an expert, I have not written books, and people do not talk about me at scroll saw conventions (do they still do those?). My experiences over several decades are my own as a hobbyist and now very part time commercial cutter. They may differ from someone else’s.

This will be a series of articles just to keep the length somewhat manageable. I will eventually cut three of the same puzzle using each of the three machines I personally own or have access to.

But first, I will review a little bit of basic information on scroll saws for the new cutter looking for a saw. Some of this will be to create a basis for some of my comments as I review my three saws. There are a lot of books on the subject along with some great websites maintained by well-known people. I am not going to attempt to duplicate all that information here. A good example of a book is “Scroll Saw Handbook” by Patrick Spielman. Mine was written in 1986, so some of the information is a little dated. I believe he released a new edition in the early 2000’s that is still probably missing new information from the last 20 years. A good example of a website is one that was created by Rick Hutcheson: Rick’s Scrollsaw (scrollsaws.com). It also appears to not have been updated in a few years. He appears to have some strong opinions, but he often posts counterpoints to his opinions submitted by others. It is kind of fun reading through some of it. There is at least one magazine dedicated to the scrolling craft: Scroll Saw Woodworking & Crafts – Everything for the scroll saw enthusiast, from tips and techniques and tool reviews to patterns and instructions for amazing projects including fretwork, intarsia, portraits, puzzles, and much more! (scrollsawer.com). This is a great magazine for more normal scrolling interests. I subscribed for a number of years, but as with many magazines, it started to become repetitive to me, and I dropped it. If you are new to the scroll saw, you may want to check it out for other ideas to try besides puzzles. Three-dimensional Christmas tree ornaments are kind of fun, as long as you do not pick a hard wood like hickory to start with!

As a related aside, you can learn how scroll saw blades are made here: How Scroll Saw Blades Are Made | Flying Dutchman – Mike’s Workshop | Flying Dutchman Scroll Saw Blades (mikesworkshop.com)

The first thing I want to comment on are the two basic types of blades. These are pinned blades and unpinned blades. The type of blade you use depends on the machine you have. Most serious scrollers are using unpinned blades. Not that you cannot make good cuts with pinned blades. Pinned blades have a positive in that they are easy to install in the saw. Everything else is a negative, from my viewpoint. The first negative is that they cannot be obtained in small enough sizes for the puzzle work I do. Here is a picture comparing a pinned blade to unpinned blades. The smallest of these is what I use to cut puzzles. I do not actually have any pinned scroll saw blades as I do not have a saw that would take them. This one is for my hand-held coping saws, but you can see what a pinned blade looks like. Notice the plastic rule on the right side. The graduations are 1/16″, so you can see the relative sizes well.

The pins go in slots in the blade holders. Quick and simple to install the blade. Once installed, they stay in place. See the picture below. This is on a coping saw, but a scroll saw taking pinned blades is not much different.

The second negative with pinned blades is that they are difficult to work with if you do any fretwork. With fretwork, you have a pattern that you are going to cut out to leave silhouettes behind. You drill a number of very small holes in the wood to thread the blade through to make these cuts. A pinned blade requires a larger hole, which would preclude many of the popular fretwork patterns out there. The picture below is a very simple piece, but pinned blades would not have worked.

And yet another example of a project where pinned blades would not have worked for certain areas. This was cut in 3/4″ thick maple with a piece of Masonite as a dark backer for contrast. This was based on a photograph of our kids taken while on vacation in eastern Maine. I made a large one for my wife, and two smaller ones for my mother and mother-in-law. I also made a number of jigsaw puzzles based on this same photograph.

Now to talk about the saws cutting action. There are four basic types: rigid arm, parallel arm, C-arm, and parallel link.

Rigid arm. With this type of saw, the cutting action is strictly straight up and down, which is great! However, the motive force comes from below the table. The mechanism moves the blade up and down. Above the table, there is a spring return cylinder. On the down stroke, the blade is pulled down against the spring pressure. On the up stroke, the spring is pulling the slack blade back up as the lower mechanism pushes the blade up. This works pretty well for larger stiffer blades, but not so well for the smaller ones. When the blade drags in the tight saw kerf, the mechanism from below keeps pushing and can fold the skinny blade and break it. I had a version of one of these from the 1950’s that had a Craftsman label on it, but was made by Atlas, I think. It was one of two of my first scroll saws. I bought the two saws as a package deal at a yard sale. I cleaned up and fixed this Craftsman saw as much as possible, but I could never get it to work well with small blades. This was 25 – 30 years ago, so my memory is fuzzy on this. It may have required pinned blades. It either had the pinned blades and I could not find small blades for it, or it had blade clamps and kept breaking the 2/0 blades. This is actually what I started scrolling with years before cutting puzzles, i.e., fretwork, intarsia, etc. (The other saw was a little light duty benchtop model that took short 3″ pinned blades. It walked across the bench whenever you turned it on. I gave it to my mother-in-law, and she loved it! Best son-in-law ever!)

The straight up and down sawing action is the best for very accurate and detailed cutting. Also, these saws do not have a lot of moving parts, so there is less vibration due to less inertia changing. Being made entirely of cast iron and weighing more than a boat anchor helped cut the vibrations as well!

There was another version of a rigid arm saw that was developed by a fellow by the name of Ernie Mellon. The saw was called an Eclipse saw. He had a belt mechanism that traveled up through the rigid arm and drove two cam shaped mechanisms at either end. This maintained a constant tension on the blade. These were very sought after with a long waiting list to buy one. Unfortunately, he passed away and the business/manufacturing went with him. I believe only a little over 500 of these were ever made. The owners of these machines are now struggling to find parts to keep them running. If you go to Rick Hutcheson’s website, he has a writeup and good pictures of this saw. Someone has made a wooden version of this type of machine you can see here: www.youtube.com/watch?v=HfY24cqG8Y8. Skip down through the detail pictures until you get to the video.

Constant tension parallel arm. This is one of the more common types of sawing action you will find. This type of mechanism has been around for quite a while. There are many wooden antique saws as well as newly manufactured saws that use this cutting motion. The advantage to this design is the geometry of a parallelogram. If you take a box and open the ends, as you collapse the box, the sides all remain parallel. In the first drawing below, you can see the key elements of the saw design.

You can see the upper arm and the lower arm. They are each supported by their own pivot point. On the left side of the drawing, you see blade being held vertically by the upper and lower blade clamps. On the right side, you can see the tension rod. Those four components make up the parallelogram. Additionally, you see on the upper right a tension adjustment knob, and on the bottom arm an operating rod. The tension adjustment knob is usually at the back of the saw and is generally adjusted based on the size of blade installed. Once the tension is set, you operate the tension release lever to release the tension to change the blade, and then reinstate the tension when done.

As the saw operates, the operating rod pushes up on the lower arm, which pivots around the pivot point and makes the other end of the arm go down. That pulls down on the tension rod, which pulls down the back of the upper arm, which pivots around the pivot point and makes the other end of the upper arm go up. The opposite “surfaces” remain parallel to each other, but the shape changes from the specific shape of a rectangular parallelogram to the squished shape of a generic parallelogram. See the drawing below.

The other thing that happens is that the blade moves backward as it moves up. Then, on the downstroke, the blade moves forward as it comes down. This is actually the cutting portion of the stroke. If you continue this out, if the operating rod continues to pull down, the blade will again move backward as the arms move through an arc. The “sweet spot” is where the blade is all the way forward and may be about where the cutting table height is designed to be. You do need to realize that the amount of motion is exaggerated for the purposes of the drawing. I will discuss this more when I talk about the specific saws I will be using.

One negative, if you will, of this is the constantly changing motion of the arms. This can lead to vibration. Manufactures do all kinds of things to reduce the vibration, but inertia changing direction causes vibration.

To show you a picture of an actual saw, here is a Hawk picture from the Bushton website. You can clearly see the pivot points, the tension rod and adjustment, the blade, and the upper blade clamp. The black blob in the middle attached to the lower arm is a diaphragm that generates a little air pressure to create a source of air to blow saw dust out of your view.

C-arm. I have not researched if anyone is currently making a C-arm saw. They were popular for a while due to their aggressive cutting ability. I have never owned or used one. These are also a constant tension saw. In this style of saw, the upper and lower arms are one casting. See the below drawing.

The upper and lower arms are one piece (and hopefully a little bit beefier than my drawing!). There is only one pivot point. As the operating rod moves up and down, the “C” assembly pivots around the pivot point. See below drawing.

As you can see, the blade varies from a back tilt to a forward tilt. Once again, this is exaggerated for the purposes of demonstration. But this made many people decide they do not want a saw like this. They felt it would make for inaccurate cutting. Those who have one seem to like them. Not having used one, I have no opinion. Rick Hutcheson was a huge fan of the Delta Q3, and he made wooden clock gears using one. If cutting a clock gear is not precision work, then I am not sure what is! Here is a poor picture of a Delta Q3 from a for sale ad on the internet.

Parallel link. This is kind of the new kid on the block, I suppose, but it has been around for decades. It is once again based on the principle of a parallelogram, but it has a twist to it. Oh, and a whole lot more moving parts and pivot points. See the drawing below.

If you look to the left, you see the upper and lower arms. They are very short. The upper and lower links extend from the arms to the back of the saw. They only move horizontally, i.e. left and right in my drawing. There is another arm to the right that is moved by the motor assembly and causes the links to move back and forth. Moving those links causes the arms to move about their pivot points, thereby moving the blade up and down. See the really poor drawing below.

This has become a very common mechanism, it seems. It is used in the very common DeWalt saws and a number of others. It supposedly causes less vibration. However, to get the same amount of up and down blade stroke, the pivoting arms have to move through a larger angular change, which also results in more blade movement fore and aft. Some people do not care for this if they are doing precision work and would prefer the parallel arm style of mechanism.

This concludes this much longer than I wanted it to be blog entry. My next entry will be information about the three specific saws I am using. The third entry will be about the cutting experience I have as I cut three more Dragon Tail puzzles using those saws.

Happy Puzzling,

Bob