Ball-cup style delta arm joint

thingiverse

I'm in the process of building a delta printer, and wanted the spring-tensioned ball-cup style arm joints for very low mass with no backlash, as described ("type 4") in this article: https://www.sublimelayers.com/2017/04/delta-arm-joint-musings.html Unfortunately, the company that was making them, Trick Laser, no longer seems to be in business and nobody else seems to be selling this part except as part of premade arms of fixed length (which SeeMeCNC sells) or commercial printers (like the FLSUN SR). So I did what anyone with a 3D printer trying to make a new 3D printer would do: designed a part to be printable. This is very much a work in progress. It has not been tested on an actual printer yet, and needs an attachment point for springs before it's usable. But I've posted it here for now in case anyone wants to experiment with it. This part needs to be printed in rigid material not subject to creep, and the material should be non-abrasive so as not to cause wear on the balls. The inner edge of the ball cup has a cutout that's intended for placement of the Z seam, so that any imperfection at the seam does not make contact with the ball. If your slicer does not automatically put the seam there, choose the option for fixed seam position and place it there manually.