Material thickness and GF supplied files

I was printing and assembling the Dodecahedron Puzzle Model which calls for medium acrylic but the assembly shows what looks like medium walnut.
I was using a 5” X 10" sheet of Proofgrade Medium Orange Acrylic - part of an order of 25 that I had purchased to make earsavers, because I always try to follow directions. No where in the written instructions is medium walnut mentioned.
As I was assembling the Dodecahedron Puzzle Model it was apparent that something was wrong. All of the pieces were assembling very loosely and it looked like glue would need to be used. Which I did on several of the pieces. When I realized that I had improperly assembled and glued some of the pieces, I proceeded to print out and assemble replacement parts.

Whoa - these newly printed parts fitted together nice and tight.

The new parts had been printed on a different 5” X 10" sheet of Proofgrade Medium Orange Acrylic - part of that same order of 25 that I had purchased to make earsavers. I could see that use of my trusty calipers was needed to find the problem.

Sheet #1 is the first sheet (unused) that printed the Dodecahedron Puzzle Model. Its thickness is .114”

Sheet #2 is the sheet I used to reprint the broken pieces. Its thickness is .120” thus providing a much tighter fit than that from sheet #1

Sheet #3 is an unused sheet measuring .118”

Sheet #4, also unused measuring .117”

Sheet #5 - Unused .115”

Sheet #6 - Unused .113”

So then I decided to try a piece of Proofgrade Walnut Plywood. Its thickness measured .128”

And the pieces were so tight that a wooden vise (to prevent breakage) and a rubber hammer was needed to assemble the parts.

It seems that scaling of the image is necessary depending on the thickness of the material.

That’s for another discussion.


Yeah, all acrylic has a pretty large tolerance of up to 10%-ish for extruded and I’ve even seen some cast acrylic listed with up to + / – 30%. :grimacing: (Each manufacturer will have a different tolerance for their material.) Even the same sheet can vary 10% from one end to another, and it’s just the nature of how it is made. It sure makes using it for things like this cumbersome though!


Agree. But why do they specify acrylic in the instructions and use plywood in the actual demonstration?

They show multiple materials in the images - and the material required on the catalog page is draftboard…

I’m guessing it’s one that works no matter what the material is, but with some (as you discovered) ranges!

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Thank you for writing in, Larry. It looks like the other posters have had great responses to your question. I’m sorry it wasn’t explicitly mentioned in the directions, but Proofgrade materials can vary in thickness, and create some unique results!

We try to provide ideas for using a variety of Proofgrade materials in our catalog pictures to inspire your creativity, so the material listed in the instructions isn’t the only one you can use. As you’ve noted though, using different materials may require adjustments so the design fits together.

If you have any other questions or concerns regarding this specific design, I would be happy to answer your question specifically if you write in to!