stealthchop: "motor phase B may be disco..."

dc42

Thanks. Please run M569 P0 to list the driver settings, then M569 P1 etc. up to P5. List the results here.

gnydick

10:09:19 AMM569 P0
Drive 0 runs in reverse, active low enable, step timing fast, mode stealthChop, ccr 0x00053, toff 3, tblank 0, hstart/hend/hdec 5/0/0, tpwmthrs 1 (4791.1 mm/sec)
10:09:18 AMM569 P1
Drive 1 runs in reverse, active low enable, step timing fast, mode stealthChop, ccr 0x00053, toff 3, tblank 0, hstart/hend/hdec 5/0/0, tpwmthrs 1 (4791.1 mm/sec)
10:09:16 AMM569 P2
Drive 2 runs forwards, active low enable, step timing fast, mode stealthChop, ccr 0x00053, toff 3, tblank 0, hstart/hend/hdec 5/0/0, tpwmthrs 1 (1890.3 mm/sec)
10:09:15 AMM569 P3
Drive 3 runs in reverse, active low enable, step timing fast, mode stealthChop, ccr 0x00053, toff 3, tblank 0, hstart/hend/hdec 5/0/0, tpwmthrs 1 (4039.1 mm/sec)
10:09:14 AMM569 P4
Drive 4 runs forwards, active low enable, step timing fast, mode stealthChop, ccr 0x00053, toff 3, tblank 0, hstart/hend/hdec 5/0/0, tpwmthrs 1 (4039.1 mm/sec)

dc42

Thanks. You have tpwmthrs in your M569 commands set much too low on all drives. StealthChop is problematic at high speeds.

gnydick

@dc42

My initial post said, no matter how slowly or gently I print. I'm not trying to print at high speed when this happens.

dc42

My guess is that stealthChop is using a very low motor current. Perhaps it hasn't calibrated itself to your motors very well. It normally does that calibration during the initial homing moves. It might work better if you change the speed of your homing moves.

You could also try adding this at the start of homeall.g:

G91
G1 S2 X0.02 Y0.02 Z0.02
G4 P100
G90

This moves all the motors a tiny amount, then pauses to give the drivers time to measure the standstill characteristics of the motors, before proceeding with homing.

gnydick

@dc42 I've already been doing that. I don't home as part of my print process, I home manually.

dc42

What do you mean by "I home manually"? If you mean that you press the Home button in DWC or send G28, that's fine. If you mean you push the axes to the right positions by hand, or do short jogging moves, that isn't, because stealthChop needs a long medium speed move to calibrate the motor.

gnydick

@dc42 I click the home button. OK, I'll look at my init code to see if it meets your suggested.

gnydick

@dc42 btw, I'm assuming I need an M564 H0 otherwise it won't move?

G91
G1 S2 X0.02 Y0.02 Z0.02
G4 P100
G90

dc42

G1 S2 moves will work without M564 H0.