Okay, so, it happened again… this time, I took pics.
I was cutting a job that took up (nearly) the entire sheet of plywood. After maybe an hour of cutting (about half way through) USB lost connection… this happens occasionally (not nearly as often since I re-routed the router power so it doesn’t run along the Z axis cable and put ferrite rings on each end of every data/power cable) - So, I start the calibration again.
First, third and fourth cuts are perfect (and I mean the physical cut order, not how they’re numbered on the calibration screen) Second cut was curvy, again.
The first attempt of calibrating, the 2nd cut was really bad. So, I shut everything down, again. Restarted, wiped the memory, restored defaults and started from “scratch”. This time, I took a photo and video of the 2nd cut, which was better than the first attempt, but still off.
It looks like the Z is lowering before it reaches the beginning of the cut, and I think this might have something to do with it. (though, not sure why) Every other cut, the sled moves into position, stops, then lowers Z.
I completed the calibration, and ran through it one more time - skipping everything until the cut test. This time, everything cut perfectly.
I create a new job to cut the missing parts of the original job, and start cutting. It completes the cut, but the corner cuts in the far bottom left corner and mid-way up the right side was way off. There were 3 other shapes, of approximate size that it cut perfectly - like, dead-on.
Here is the cut in the bottom left corner. As you can see, it didn’t follow the same path between the first and second pass:
And here is the cut on the right edge of the board, about half way up:
12’ top bar, approx 2’ above the work area. I’ve cut in these areas before, just fine… only thing I’m wondering is, why the z axis starts to move before the sled reaches its position - this is new, haven’t observed that before. And maybe a separate but possible issue - this sheet of plywood was exceptionally rough (Lowes) and really scared up the bottom of my sled - going to have to sand it down smooth again - could that have anything to do with it - and if so, why just those two particular corners (both passes) and not the other 18 corners on the same job?
Anyway… if anyone has suggestions, ideas, I’m all ears. Thanks!