Ball-cup rod end, parametric

Ball-cup rod end, parametric, made in openscad

What I really wanted was the Trick Laser Ball-Cup Rod Ends Retro-Fit Kit, but I wasn't comfortable paying $39 (ouch!) to have the $35 set of ball-cups shipped to Europe.

So I made this and printed a set in ABS for my 10mm rods.
They work really well together with the "Ball-stud ends for Haydn Huntley’s magball delta arms", bought from duet3d.com.
I made the spring hooks from a couple of paper clips.

Not sure how quickly these ball-cups will wear out though...
But since I saved $74 (less the cost of filament, paper clips, springs, and time of course) by making these myself, I guess it's ok to replace them once in while. If need be. :)

Adjustable:
* ball diameter
* rod dimensions
* distance from ball center to rod end
* diameter and placement of the spring hook hole
* how far the rod inserts go into the rods
* and so on...

You probably have to experiment with the ball_dia setting to get a snug fit between ballcup and