Sunday, November 30, 2008

Y Axis Cleanup

I think I found the Y axis problem. It looks like the X motor mount was catching on impefections of the rod it rides on. Two points seem to be a problem:

1. The block that constrains the lower side had a sharp inside edge. This seems to have been due to the molding process. Mine are molded parts, not printed or laser-cut. I removed both of these blocks (one on either side of the motor) and ground down the edges.

2. The rod was also catching on the side of the hole it passes through. When properly calibrated, the rod shouldn't even touch the plastic. I could've sworn I had that right in the first place. Best guess is that the X axis shortened over time due to a) X belt tension and b) the fact that I didn't tighten the X axis rods enough. I loosened the X belt, adjusted the X axis length and tightened everything back up again.

After that, I cleaned and lubricated the Y axis rods and used the stepper exerciser to run it through its paces. Seems to be behaving now.


nophead said...

I haven't run my Darwin for any length of time but it's hard to see how the y-axis could jam.

I think the bearing blocks should be inside the motor mount, not outside, but I can't see that would make any difference.

The rod is vertically central in the hole on my machine. Have your rods worn flats where they run over each other? If so you could rotate them.

Steve DeGroof said...

Thanks. I checked and, while there don't seem to be any worn spots, there does seem to be some corrosion. It was probably there from the beginning. I may need to take some steel wool to it.