This evening I had only a few spare moments, so I raced downstairs and plugged in my soldering iron. Within a minute or so the tip was hot enough to melt solder, and I tinned the ends of the stepper wire that I soldered to the Y axis motor last night. With the motor attached to the table, and the table back on the mill, I was eager to see how it would do!
So, the motor did just fine. I should be able to run it at 3 amps, but the driver started getting uncomfortably hot. No big deal. I dialed down the power a bit and ran through the paces. In and out fast, then slow. I ran the table all the way to the column, then all the way back out. I slowed as I neared the end of the ball screw that caused me so much grief at the beginning of this project.
My solution to the “problem of the lost bearings” was to drill and tap a hole at the end of the ball screw. I used the hole to affix a washer to the end of the screw. Brilliant, no? Since I was testing the machine I decided to make sure the screw would stop it.
Perhaps you wondered about this too, if you read the description of my solution. The Y axis stepper motor is rated at 425 inch ounces, and the table weighs about 40 lbs. I inched the machine closer to the end of the axis, and then, with no hesitation whatsoever, the machine pushed the retaining screw out of the way and continued barreling toward the end of the shaft.
Brilliant!