Another day lost to the lathe

Post date: Mar 2, 2014 12:54:52 AM

After getting my new table installed and the new leadscrew aligned with the bearing, I realized that the stepper won't stay aligned with the leadscrew. In other words, I couldn't use my new couplings, which depend on superb alignment. What's the logical thing to do? Complain. But after that, to make a new bearing clamp and stepper mount combo to ensure perfect alignment. So there went my day.

The mount was made from a chunk of ~2" solid aluminum round stock. It probably would have made more sense to have started with a thick-walled tube, but I didn't have any of that.

The left image above shows the top of the mount. The indented ring you can see is used to align the stepper, while the deeper region is to house the coupling.

The right image above shows the side and bottom of the mount. The hole in the side is used to tighten the leadscrew end of the coupling (the stepper end is tightened before it's inserted into the mount). On the left, you can see a narrower disc. This is used to align the mount with the countersunk circle etched into the back of the stepper mounting plate. The very center hole is for the leadscrew bearing.

There weren't any really novel methods used in making this- just a LOT of drilling on the lathe (for the large center hole) and careful measurements (for the stepper alignment indent and especially the bearing indent- both depth and diameter). On the up side, it fits perfectly on the machine, and the stepper and leadscrew seem to be aligned very well- at least the screw turns with no complaints.

So after a whole day of work (well, 1000~1800, so close enough), I've got one e axis that seems to be about as close to perfect as I can get it.