The CNC Router appears to be OK. Not apparently out of square or bent to any detectable level.
It’s tough to solve intermittent problems like estops. Please communicate problems found via the mail list.
As to the Pinion Gear replacement, my conclusion was to install the new gears and keep them greased. The X pinion has been replaced.
The gear fits nicely. I also adjusted the X carriage and now it runs across the carriage smoothly under hand power.
Ran out of time to do the Y axis today.
Maximum torque on the shoulder bolt into aluminum is the lesser of 1/3 turn of the bolt after snug or 140 inch pounds (11 ft lbs)
THere is loctite in the glue bins for securing the threads. Next opportunity to install the Y axis is Tuesday around the meeting.