Overview:

Years ago, I made a “Splat the Rat” game for our church festivals and had come up with a fancy collapsing set of legs and braces to make it more compact for storing. However, it was a pain to fold all of the legs and braces at once then wrap a bungee cord around it all.

After dealing with the pain so many years, I came up with this design.  It involves drilling a pocket on one part with a ¾” Forstner bit and inserting the female part of the latch.  The male, TPU portion gets installed on the mating part.  The parts lock securely together while still being reasonably easy to separate.

I also designed a jig that makes it easy to ensure both sides line up.  Refer to the pictures and steps below for assembly instructions:

1. Line up the two mating parts and determine a reference point that can be used for both sides then draw a line.
2. Line the jig along this line and mark each of the openings.  The center one will be for the pocket and the others for pilot holes/screws.
3. Use a ¾” Forstner bit to drill the pocket at the center location.  This should be slightly deeper than the female part (just under ¾” in my case when using 2x4s).  Drill pilot holes for the screws, then insert the female part and screw in place.
4. Line the jig along the reference line on the opposite part and mark the four corner holes for pilot holes/screws.
5. Drill pilot holes for the screws and mount the male portion.

Printing:

The male/sphere latch needs to be printed in TPU (95A as an example). The other parts can be printed in PLA, PETG, ASA, etc.  No parts require supports if printed in the orientation shown.