How can I add closed-loop stepper motors?
-
Hello. My RatRig always snags on something during a print, so I want to get some closed-loop steppers so the printer can correct itself and I don't have those massive layer shifts anymore. My current motors are LDO-42STH48-2504AC, I don't know which motors I should get to replace them. I have the Duet 3 Mini 5+, do I need to buy a different board? Thank you all for your help.
-
@tylersuard
First step is to check if the motors are running in spreadcycle. Please post your config.g.
It's a common problem for the 2209 drivers -
@tylersuard If the head crash causes a pulley to slip on a shaft, or a belt to jump a tooth, or the build surface to move, then closed loop steppers are not going to help. Nor will they improve the print defect that causes the head crash - the part will still be defective and either not function as intended or not be aesthetically pleasing. Far better to fix the root cause and fix the problem that is causing the head to crash, which will likely take less time and cost less money than fitting closed loop steppers IMO.
-
@tylersuard one option is to use EXP1HCL expansion boards to drive stepper motors with built in quadrature encoders. They can be connected to your Duet 3 Mini.
We also have in prototype form magnetic encoder boards that can be bolted on the back of existing 1.8deg stepper motors, for use with the EXP1HCL; and we have other closed loop options under development.
As @DIY-O-Sphere suggests, if you currently run the X and Y motors in stealthChop mode then switch them to spreadCycle to better handle obstructions.
