Y axis jumping for no apparent reason
I've been successfully printing a bunch of little things. I tried to print my first tall thing and at about 47mm high it began jumping about 2mm for every 1-3mm in height (sporadic). Before that it printed perfectly. I started a second print of the exact same g-code and it made it to 60mm before it started jumping. I added a fan to keep the motor and drivers cool as suggested elsewhere.
Any advice on this? All movement seems to work smoothly. X makes a funny resonating sound occasionally but it doesn't seem to be affecting anything. The belts aren't saggy but they're not too tight and I can't feel any backlash. There doesn't appear to be any mechanical obstructions.
So far the common theme on these two is that they're the only thing I tried to print over 40mm. I'm really not sure how that could affect things. I tried to force the motor to skip a step back to the correct alignment and it was very strong (suggesting it wouldn't be easy to knock out of alignment) and of course I couldn't get acceptable alignment anyway.
Re: Y axis jumping for no apparent reason
I had the same problem and it was suggested that silent mode can cause this issue on longer prints. Basically, silent mode causes the motors to work harder and this results in extra heat. Extra heat can result in skipped steps which can cause an axis to shift.
The more plastic is laid down the harder the Y axis motor has to work to push the bed around. So it makes sense that if silent mode makes the motors work harder that it could cause such an issue with larger prints.
Re: Y axis jumping for no apparent reason
Just an update, I tightened the belts and the problem did seem to go away. They weren't loose at all before, but I guess it was loose enough to skip. I measured the size of the steps and they're the same size as the teeth on the belt.
I will investigate the silent mode but I don't think I'm using that.