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bigtreetech / BIGTREETECH-S42B-V1.0

The closed-loop drive is to feedback the rotation angle of the stepping motor to the control panel, compare the distance that needs to be rotated with the distance of the actual rotation, calculate the error value, and then compensate, so as to prevent the problem of multi-step and lost step. The closed-loop drive can completely overcome the lost step of the open-loop stepping motor, and can also significantly improve the performance of the motor at high speed
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When closed loop is set it stops moving #12

Open JanLichtarowicz opened 3 years ago

JanLichtarowicz commented 3 years ago

I have installed a S42B (pre assembled) only on my Y axis using a SKR 1.3. When printing in closed loop the stepper stops or will jump large distances. I have modified my marlin 2 for the correct stepper by commenting the Y stepper driver and also modified # define MINIMUM_STEPPER_PULSE 3 and # define MAXIMUM_STEPPER_RATE 150000 in the configuration_adv.h file. I have also managed to calibrate my steps per unit. It starts to print ok but will suddenly stop moving and give a whine from the stepper. the printer keeps printing now but horizontally. It then may start jumping backwards and forwards at random intervals. See attached picture. 20200822_135456 When I set the stepper to open loop it prints fine. Can anyone shed some light on this.

Baltojikale commented 3 years ago

Had same problem, with 8 bit board gt2560. changed to much faster skr 1.4 turbo. Possible solutions reduce acceleration to 550 for x y, also reduce microstepping.

Quas7 commented 3 years ago

Just brainstorming: Could it be, that the magnetic field is too weak or too strong (2nd red light lighting up before erratic moves)? I mean, is the surface of the manget really parallel to the shaft (not tilted) and the board leveled and centered to the magnet as well as ~2mm airgap in between?

I also observed similar behaviors in my bench tests with bigger motors (see here: See here: https://github.com/bigtreetech/BIGTREETECH-S42B-V1.0/issues/19). What kind of NEMA17 do you use (mainly body lenght)?

davidcgu commented 3 years ago

Did you get it solved? This seems fkg useless.... so I removed a TMC2209 to test a close loop as improvement and seems close loop mode does not work, what means at the end you just install a A5984 driver, what is really a old crappy & obsolete driver.....

My first impresion is that this seems a total scam....