TPU Ball Joint/Hinge Swivel Joint

EDIT:for better clarification, this acts more like a “hinge and swivel joint” as opposed to a typical “ball socket” joint.

PLEASE NOTE: This was designed for TPU with a shore hardness of 95a, anything softer will not work.

Pictured: Printed in esun TPU95A Gray

This here's another design for joints to be used in toys or for whatever other project you might have in mind. I wanted to make something that would function and move easily like a toy, but still hold firm and not wear away like most regular toy joints and 3d printed ball socket joints usually do. 

Enter TPU 95a, which had the exact friction i was looking for, and doesn't wear like PLA does, but it still has a few design parameters to consider. For one thing, you should print this part at at least 1.5 inches, 3.5 centimeters or 38.1 mm on Y for this to function, any smaller and it won't print accurately and won't work as it should, feel free to scale it up though.

For settings i recommend whatever recommended print temp settings are listed for your specific TPU95a filament, print slow like 40mm (or reasonably fast at 60mm if you're impatient like me), estimated print time is around 20-30 minutes, maybe more depending on your settings. Standard quality .2mm layer height in Cura should work fine but super quality will improve the overall quality. I definitely recommend supports, simple line supports will do the job and are relatively easy to remove, PRINT THE BALL JOINTS SOLID!.

Also included is a file with some octagonal sockets that you can boolean cut into whatever model you want using whatever modeling program you'd like. This way you can easily add ball joints to whatever model you'd like to articulate. The last image shows how the joint will fit into the socket, as opposed to a perfect circular hole which requires more precise printing, the octagon socket will compensate for any deviations in the final print and still function as it should. 

I also should note that the ball joint to socket connection will work MUCH better if both parts are printed in TPU, especially with the model with the socket having a low infill (like 10%) for better socket flexibility. Although it can TECHNICALLY work with other non flexible filaments like PLA, ABS, PETG, ASA etc, the friction difference is a little more rough and may even cause the joint to twist like rubber in the socket and stay in one place instead of swiveling, YMMV of course.

That ends my book report, in my experience, printing TPU95a is a lot easier than others would leave you to believe, it's actually one of the easier to print TPU filaments. Be sure to share anything you've made with my design, remember to credit me, and happy printing!