I love design but I don’t much care for assembly. Why should you have to deal with glue when your Glowforge can make the fasteners for you?
I did some experimenting with serrated edges on tabs, and the results have been terrific. Proofgrade plywood is very consistent in thickness, so when using it, you can reliably depend on a design with serrated tabs to go together with a few taps from a rubber mallet.
I’ve printed a single serrated design from Proofgrade maple, cherry, walnut, and I think Draftboard too. Every one went together perfectly.
The trick is taking a little serration (shown here in blue top-left) and adding it to every protrusion. Steps:
- Create a tab and a slot that are the same size
- Add the serration and its mirror image to both sides of the tab
- Align the serration so the gentle slope points towards the direction of insertion, and the midpoint of the serration is on the edge of the tab (see picture top-right)
- Use the “union” or similar tool to join it into one single shape
- Print and bang together
The serration is 0.033 inches tall, which means it protrudes 0.0165". The kerf should be about 0.008, so imagine the hills smashing down into the valleys to fill up the kerf. It holds very tightly, but can be forced apart with pliers if needed.
Here’s an SVG with the example images.
serrated.zip (1.3 KB)
This was my test design - it shows tab-and-slot, plus some other variations on the technique.
Note that this is my personal project and is not supported by Glowforge. (I do get to do them occasionally ).