Need help designing an interlock between two 3D printed components

[fred_dot_u]

I purchased a model print from Angus of Makers Muse to determine the print-in-place capability of my printer. I can print models with 0.4 gaps and expect the parts to move, but at 0.3 mm, they are stuck together. That's print-in-place, but separate print clearance is different due to "elephant's foot."

For your application, you don't have to have precise, tight fit and a small bit of play won't hurt the assembly. If you sand or otherwise cut away the elephant's foot, you could probably build a model with 0.5 mm clearance and have minimal problems, unless your printer is out-of-tune.

Consider also to create a block test of only the portions of the joint that are in contact. You need only to print it about 4-6 mm high for a good test piece. Short duration print, minimal filament use and you'll be able to check easily if it's safe to make the full print.

[JeffZ]

Sounds good. I don't own or have access to a printer, so i'll be ordering the print online, probably from 3D Hubs. Thanks for the info on gaps, that gives me a starting point. Maybe I'll split the difference and go for .4mm gap

Also, I just found this article on 3D Hubs which confirms your recommendation!

How to design Interlocking Joints for fastening 3D Printed parts

Interlocking Tollerance.JPG