This can be printed with a layer height of 0.2mm or 0.1mm. Use a shell thickness of 2mm, so that all of the walls will be printed with concentric circles, instead of back-and-forth infill. For PLA, use a relatively low temperature, like 185C, so that the overhang inside of the ball bearing sockets comes out as cleanly as possible. I use a 3/8" ball end mill to gently clean out the ball bearing sockets.Note: I have to print out at least two of these at a time, to get the correct dimensions.  I usually print out a dozen of the ball bearing holders, followed by another of the rod ends -- ie. I usually don't mix them in one print run.I use these with my magnetic effector:  https://www.youmagine.com/designs/magnetic-effector-with-3-fans-and-led-light-ring-for-kossel-plusAnd magnetic carriages: https://www.youmagine.com/designs/kossel-plus-magnetic-carriage--2Contact haydn.huntley@gmail.com if you need an inexpensive source for the ball studs or magnets.