Originally Posted by
Ripthorn
Sorry for the late response, I've spent most all of my free time out on the machine. Here are some things I discovered:
- There appears to be a decent amount of preload in the bearings. Putting some weight on them makes them move easier. The motor/screw should be able to handle it well.
- My frame was out of parallel by about 1 mm over the 1500 mm length of the machine. I have fixed this and it seems to help a little.
- This upgrade kit came with no instructions and several parts either missing or sized wrong, even for the other parts they provided. This resulted in some guesswork on my part. For example, there were no included spacers for the Y axis delrin screw blocks, so I had to kind of guess at the length based on measurements I could take. Turns out that the spacers I made were resulting in binding of the screw in the blocks at the extremes of the travel. I have fabricated new spacers that are a little longer and that seems to help some.
- I reduced the Y axis acceleration and the problem happens less frequently
- I ran a test program where it was running perfectly for 35 minutes doing rapids and various cutting procedures: pocketing, adaptive clearing, contouring, etc. Out of nowhere at the very end (some 64000 lines of G code later) it decided it would bind up on me. A second test cut of a different routine resulted in a similar situation where tens of thousands of lines into the G code it just bound up unexpectedly and gave me issues.
When it binds up, it's because one axis isn't turning while the other is. This can result in a mismatch in the Y position of the two sides of the gantry by as much as 0.2" or more, which I have to manually fix by disconnecting the stepper motor and turning by hand to get the two sides to match.
I would love to get this to the point where I can trust the machine to do the right thing. I have some appropriately sized Zerks coming in the mail, so we'll see what that does. In all, I've made progress, but I still can't just trust the machine to run a program perfectly end to end.