Sooo, after having my CR10 for more than a year, I finally actually tried printing something big on it. Everything I’ve printed before this has used less than 200g of PLA and finished in less than 24hrs. I’ve had a 1200g print going for 82 hours now. I’ve very happy with my work on this printer over the past year, but it had a layer shift around 50% of the way through, another around 75%, and then it’s had 2 around 90%. All in the Y axis.
My run_current is 1.064, the default for Creality’s steppers, and my Y stepper is already pretty hot. I do have active cooling on my drivers now but I’m concerned that raising the current will just make the steppers hotter and the effects of heat will diminish any torque I would have gained from raising the current.
Does anyone have any hard numbers for how hot a stepper motor can run before it looses strength?
Here are my thoughts based on my experience: I think your run_current is too high and the steppers are overheating.
I have a 24v CoreXY running TMC2130 on the X and Y stepper. I originally had BTT v1 steppers, with the chip on top. I also have a fan blowing across the steppers/heat sinks. After printing for long periods of time, I’d get layer shifts. If I waited awhile between prints, the steppers would cool and the next print would be good.
I ended up upgrading the steppers to v3, where the chip is on the underside and they have a nice heat pad available. I also put a larger fan blowing on the steppers now too
run_current = 0.80
This is about the minimum current I need to get the gantry moving.
I would check what is the minimal run_current you need and make sure you don’t have a hold_current in your config. Recently The TMC settings have been revised with new recommendations.
The higher the run_current and the faster you print, the hotter the steppers will get.
Hope this helps.