Design Guidelines for Snap Fit Joints


#1

I want to print parts that can be assembled. I have no mechanical engineering background so I didn’t even know the relevant terminology. After a bit of research I learned that one way to do this is with snap-fit joints. I looked for design guidelines online on Google and amazon, figuring there must be well-known rules for how to design joints that are strong and reliable.

I found these great free PDFs, all by chemical companies:

These books also seem to contain a lot of useful information (according to their amazon previews), but they probably go well beyond what I need, and they’re not cheap:

Feel free to recommend others if you know any.


Retro Form 1+ Guide
#2

Yes, follow these guidelines and your prints should come out more predictably as well.

Good luck!


#3

The challenge with snap fit joints is that the current generation of resin gets very brittle as it cures.  When it’s still “fresh” a well designed joint can and will work (I’ve done plenty), but after a week or two of continued curing, the joints will typically break.  A “snap fit joint” requires the material to flex, just a little, but flex all the same, and well cured Form Labs resin does not like to flex at all.