1515, It seems to home in all axis fine but when I jog X to the left it'll suddenly stop and it sounds like the stepper is crying. I've triple checked the wiring and can't find anything. checked vwheels and see no issues. I don't see any physical binding of the lead screw. It stops suddenly like it hit a limit switch. I would think if it was binding it would try and force it's way through. I lowered max speed and acceleration to a crawl, even though I made no adjustments previously. Still stalls with turtle speeds. It seems electrical in nature but I can't see anything. I've had the machine for almost two years now with zero issues. Thanks for the help.
Correct, and the profiles are close, but if you experience symptoms (or have any deviations from standard, 3rd party parts) or just differences in assembly (Leadnuts still bedding in, some wheels a little tight) you are welcome to play with the Grbl parameters to suit what your machine needs in reality for your specific setup. See Home · gnea/grbl Wiki
It's all OB stuff and has worked flawlessly with the speed settings. I lowered all the X speed settings to a turtle crawl and it's still showing the same issue. I also loosened all the applicable wheels.
Also look for anything that might be causing your leadscrew to be misaligned (nut blocks vibrated loose, damaged bearing etc). I have similar symptoms on my workbee when I am experimenting with silly max speeds, by which time I'm getting quite severe leadscrew whip, and I suspect the sudden stop and squeal from the stepper is because the leadscrew is at an angle (because of the whip) to the nut blocks. Alex.
On to something here. With machine off I can rotate screw coupler by hand and it moves freely to the right. When I try and rotate it left it's much harder to turn. I loosened the backlash nutblocks and it was still hard to turn. Could it be something with the wheels?
Do disconnect the motor from the controller if you are turning it by hand (or disconnect the motor from the leadscrew). As to why its harder to turn in one direction, that's a bit harder to diagnose without being next to the machine. What happens if you slacken off the eccentrics completely? Did you check the bearings at each end of the leadscrew? - and that they are properly seated and lock collars secure? Alex.
Is it possible for a 1500mm leadscrew to become bent enough to bind the axis? Where I'm at: eccentrics fully open, I can spin all wheels easily with finger Both backlash nut blocks are loose All lock couplers secure Bearings like new When I completely loosen the tension nut on the end of the screw the axis operates normal. As soon as I put a little bit of tension on the lock nut it'll reproduce the stall. When I turn the coupler by hand (stepper unplugged) I can watch the lead screw rotate like it's an exaggerated U shape. Maybe .5in run out. Only thing I can think of is the lead screw is bent to hell but I have no idea what would have caused that. I appreciate everyone's help.
Possible yes, but usually wouldn't exhibit symptoms at low speed - plus you'd be able to see the whipping if it was bent If you disconnect the stepper from the shaft coupler - and run the motor - can you stall it easily by hand? (carefully grip the motor shaft)
I think I figured this out, with everyone's help. One of the thrust bearings had a tiny gouge in it. I didn't see it when I inspected it the first time and not sure how it happened. I switched the thrust bearing to the other side and the machine stalled moving to the right, works fine jogging left which is a pretty good indication. I also removed the lead screw and rolled it on a flat table and there wasn't enough wobbling for concern. Cheap part to replace so hopefully that'll do it. I'll report back with an update.
