These are made out of chrome plated steel (for maximum magnetic strength).
The screw at the base is the usual M3x10.
The ball at the top is 3/8″, which is very close to 10mm.
You can use a 10mm socket to easily tighten them without marring the balls.
Besides the carriage, I have tested and working designs for the effector and rod ends, which I’d be happy to share on a non-commercial basis.
The carbon fiber rods came from TriDPrinting, and I also found an inexpensive source for extremely strong N50 magnets.
If you need some of the parts printed, I can even help with that.
Air mail and handling in the USA for *any* quantity is a flat $4.
I’m one of those weird people who enjoys logistics, and should be able to ship them out the next day.
Francisco Peebles, Matt and Stan Williams