I am working on a fairly elaborate box design and finessed all the measurements making adjustments to thick PG draftboard. Then when I went to make the “real” box out of thick PG plywood, I discovered that the “thick” PG draftboard is actually a completely different thickness than the “thick” PG plywood. Isn’t the whole point of draftboard that you can use it to test your design with cheaper material before burning up expensive stuff? If I have to completely remeasure all the designs and test it using the expensive PG plywood, what is the point of draftboard? I feel like I’ve wasted hours of time and a fair amount of money and have to start over.
What are you designing in?
Okay, I’m of no help then.
Guess I never thought of it that way. To me draftboard is a material for testing designs, but I never expected it to be the exact same thickness as Medium Plywood. There are differences between the various plywood types, too. When making boxes or anything else that needs to “fit,” I measure every single piece with a set of digital calipers and adjust accordingly, PG or not.
Obviously, ymmv. Best of luck moving forward.
i never really thought of draftboard as testing for designs. it’s just a different medium for someone who doesn’t need a finished wood product like hardwood or plywood. it’s basically a version of MDF, the same stuff (i believe) that’s in the core of the plywood products.
if i do testing, i generally do it on cardboard. cheaper (often free), faster to cut. it may not all fit together perfectly, but the perfect fit itself isn’t what i’m testing for. i’m testing concepts.
but that’s me.
You’re going to find that materials change thickness even between vendors or batches from the same vendor. The PG materials tend to be more consistent, but there have been variations over time there, too.
As well, kerf behavior can change between materials, too. I.e. a relatively soft material may do better with a tighter fit that would cause a relatively brittle material like acrylic to edge fracture or crack.
At least, that has been my experience.
I’ve found that design longevity for designs that involve overlapping assembly (i.e. notches and/or tabs, etc) requires modeling that can support parametric values and, in particular, parametric values for the thickness.
Unfortunately, parametric modeling is hard. But even a relative idiot like me has managed to be productive in Fusion 360 and I’ve successfully cut some of my designs across a wide range of thicknesses by just changing 1 number!
Also, the GlowForge makes this somewhat easier in that you can separate the structural cuts from the adornment/decoration bits. That is, keep your scores and engraves separate from your cuts and then either combine them using something like Illustrator or Inkscape or combine them in the GFUI.
Whether people have thought about using draftboard to mock up designs or not… I’d say that this is right in the description of the material:
Its thickness matches Proofgrade hardwoods and plywoods, so you can run a trial print to work out the kinks and ensure hinges or other joinery fits flawlessly before printing a final version using finished materials.
+1 to the variations between batches of even the same material. I have run the same design on different batches of the “same exact” medium proofgrade maple, and had perfect fits become too loose or too thick because I didn’t bother to measure the specific piece I was going to use. If you’re relying on very tight fits, you’re going to have to measure each piece.
The way I work around slight variations in thickness is the use of @Dan’s Teeth in the design.
Give them a try, they work wonders.
Draftboard is great for “rough drafts”. It’s particularly handy that medium Draftboard and medium Proofgrade plywood are usually the same thickness, to a few thousandths of an inch. But thick Proofgrade plywood has a lower tolerance so it will vary more.
One nice trick about the teeth is that you’re mating a cut part to a cut part, so if your material varies, you can make the slot wider to accommodate thickness variation and depend on the serrations for strength.
All that said, @leman, I’m so sorry for the inconvenience it caused you. That’s frustrating.