Tension and Compression

I’m building a fairly large machine (45 x 38), and have learned some things I thought I’d share:

Get the good conduit. The stuff at Home Depot and Lowe’s does not have a nice, smooth finish. This creates rolling resistance, which will bite you later. Go to a real electrical supply store. It’s twice as expensive, but we’re talking about $5 / 10 feet as opposed to $2.50 / 10 feet. The real cost will be going out and finding the right stuff.

Getting the machine to be square and precise:

How much you tighten your 1/2" bolts on the various parts, matters a great deal. I couldn’t get accuracy at first. Ended up tightening the crap out of everything. Nothing would move. Back off just until you get smooth movement. Kind of like leveling the build plate on your 3D printer. There’s a magic moment where you get movement, and can’t hear jitter. That’s the thing you’re looking for.

The belt is the final part of the equation. Too tight, and the motors can’t move. Too loose, and the belt can slip around.

As the machine gets larger, the tolerance at each end of the X/Y center axes gets sloppy. This is where adjusting belt tension and also manually tuning the stepper to bring them into alignment at either end comes into play.

I’ve actually left my feet unattached - screwing them down too early locks the machine into a certain shape which might not be quite what you want. I’d wait on that until you’ve got everything else in alignment.