This weekend I attempted to lubricate the thrust bearings per the instructional PDF provided by Axiom Precision. While disassembling the z-axis assembly, I deviated from the instructions to clean the ball-screw. It slipped my attention that I was turning the ball screw past the ball-nut, and I heard the dreaded sound of tiny-steel-balls landing on my spoils board. I immediately stopped, and took a few minutes to gather all the steel balls. I re-inserted them into the ball nut, and finished the rest of the lubrication instructions.
Once reassembled, I manually ran the z-axis up and down without any problem - except for a small "thump" sound that occurs only once in each direction. Now when I run cut files the z-axis stalls inevitably. I assume that I missed some steel balls (which could have easily rolled away).
I understand this is entirely user-error. Has anyone here made this mistake before? I'm afraid that I might need to buy a whole new ball screw assembly, unless the ball nut can be repaired (filled with appropriate number of steel balls).
I left a voicemail and email with the Axiom team this morning, hoping to get my machine running asap.
Last Edit: Jan 30, 2018 23:54:55 GMT -5 by valentin
Post by savannahdan on Jan 31, 2018 7:25:48 GMT -5
That's got to be similar to herding squirrels. I keep a couple of long handled magnetics with the heads wrapped with a zip lock bag for picking up metal objects. That's not a guarantee that it will get all of what I drop. Glad you posted so that I can be careful doing this maintenance chore. Good luck and keep us posted on the outcome.
Problem Solved! I took a closer look at the ball-bearings that I had packed into the ball-nut, and I found one ball that was smaller than the rest! There's a chance that this is by design, but I figured that I mistakenly inserted a rogue ball, which must have been lingering under my machine who-know how long. I removed the runt-ball, but the Z-Axis problem persisted. Finally, I spent an hour trying different alignments mounting the ball-screw and the spindle bracket. There are four screws that hold these together, with about 1-2mm of horizontal play. The key was to assure that the spindle bracket could move freely up-and-down before remounting the spindle and stepper motor. Now my AR-8 Pro is milling 3-D reliefs like a champ again!