First, my Duet 3 Mini 5+ has lost two of its 2209 drivers to shorts, and I cannot identify the cause. I'm reliably getting "Phase A/B short to VIN" and unresponsive behaviors from drivers 0 and 3. I have ordered a replacement board, but I'm afraid I will ruin another driver or that the drivers were faulty.

The culprit printer is a Cartesian machine using a meanwell 24V supply (23.5V). Pictures of the wiring and the printer are attached. The motors are as follows:

X axis: Moons MS17HA2P4100 (11.2mH inductance: set to 800mA, rated for 1A)
Y axis: StepperOnline 17HS19-2004S1 (3mH inductance: set to 1200mA, rated for 2A) <axis that is shorting
Z axis: Moons unlabeled (integrated leadscrew motor from ~2014) (~9mH inductance: set to 600mA, don't know rating)
E axis: Revo Hemera XS (pancake motor I'm assuming from LDO) (? inductance: set to 500mA, don't know rating)

I printed for a while with zero issues using spreadcycle (was noisy) and stealthchop (was quietish). In the process of setting up sensorless homing/tuning stealthchop and stallguard, I shorted the first driver (3; Y axis). I don't know how I did it, but here is the gcode (y axis homing) that ran immediately before that short:

G91                     ; relative motion

; Stealthchop Tuning
M18 Y                   ;y off
M569 P0.3 S1 D2         ;> spreadcycle 
G4 P200                 ;wait
M569 P0.3 S1 D3 V0	;> stealthchop
M400                    ;   (clear)
M913 Y100               ;> full current
M17 Y 			;y on
G4 P200			;wait to allow driver to initialize parameters
;
G1 H2 Y-0.1 F1000	;tiny move w report
G4 P200			;wait 200ms (>140ms)
G1 H2 Y-18 F4800	;medium velocity move to y-18 w report
G4 P200                 ;wait

; Homing
M400
M913 Y50                ;lower current to y 
M201 Y500               ;lower acceleration
M566 Y60                ;lower jerk
M915 Y S-10 F0 H200 R2  ;set high sensitivity   
;
G4 P200			;wait
G1 H1 Y180 F5000        ;move to Y axis endstop w report
G92 Y170		;set coordinate to Y max
M400
G90                     ;absolute motion
G1 H2 Y165 F1200        ;move away from max to allow X movements

; Restore Settings
M400
M913 Y100               ;% current
M201 Y9000              ;acceleration 
M566 Y900               ;jerk 
M915 Y S10 F1 H400 R0   ;set sensitivity & disable reports

Here is the relevant bit of my config file for motors and such:

; Drives
M569 P0.2 S0 D3 V0                                 ; physical drive 0.2 goes forwards
M569 P0.3 S1 D3 V0                                 ; physical drive 0.0 goes backwards
M569 P0.4 S0 F12 Y5:0 D3 V80                       ; physical drive 0.4 goes forwards
M569 P0.1 S0                                       ; physical drive 0.1 goes forwards
M584 X0.2 Y0.3 Z0.4 E0.1                           ; set drive mapping
M350 X16 Y16 Z16 E16 I1                            ; configure microstepping with interpolation
M92 X177.78 Y177.78 Z400.00 E397                 ; set steps per mm
M566 X900.00 Y900.00 Z1200.00 E120.00             ; set maximum instantaneous speed changes (mm/min)
M203 X19200.00 Y19200.00 Z2400.00 E2400.00         ; set maximum speeds (mm/min)
M201 X9000.00 Y9000.00 Z2400.00 E250.00              ; set accelerations (mm/s^2)
M906 X800 Y1200 Z600 E500 I10                       ; set motor currents (mA) and motor idle factor in per cent
M84 S1                                             ; Set idle timeout

; Axis Limits
M208 X0 Y0 Z-3.5 S1                                   ; set axis minima
M208 X301 Y171 Z180 S0                             ; set axis maxima

; Endstops
M574 X2 S3                                         ; configure sensorless endstop for high end on X
M574 Y2 S3                                         ; configure sensorless endstop for high end on Y
M574 Z1 S3                                         ; configure sensorless endstop for low end on Z
M915 X S3 F1 H400 R2                               ;set sensitivity   
M915 Y S10 F1 H400 R2                              ;set sensitivity 
M915 Z S3 F1 H400 R2                               ;set sensitivity   

After I started getting the "Phase B short to Vin" warning, I suspected the motor and immediately ordered a replacement motor. After getting the replacement, I set up the Y axis on driver 0.0, which was the unoccupied driver. This motor has an integrated harness, so the wires were new too, and I test each harness before connecting to the duet. Same thing happened - that homing code fried the Y axis driver after 3 or 4 runs (motor moved fine).

Second, I have figured out the hard way that the 2209's do NOT like my (relatively) high inductance moons motors on spreadcycle. They are noisy and no set of hysteresis, blanking time, or other variables has rendered them silent. For others who may read this: it is probably best to avoid high inductance motors if you want to print fast and quiet on the 2209's. I have also had a lot of trouble with stallguard with this particular printer; I'm guessing sensitivity settings vary depending on Vin. Maybe the spreadcycle-dependent stallguard on the 2660s (Duet 2) is more resilient to fluctuations induced by loads like a bed heater?

Here is the homing code for the X axis, which has the highest inductance motor: (please note the high sensitivity and low current that I have to use)

G91                     ; relative motion

; Stealthchop Tuning
M18 X			;x off 
M569 P0.2 S0 D2         ; > spreadcycle 
G4 P200                 ; wait
M569 P0.2 S0 D3 V0	; > stealthchop
M400			; (clear)	
M913 X100   		; > full current
M17 X 			; x on
G4 P200			; wait to allow driver to initialize parameters
; 
G1 H2 X-0.1 F1000	; tiny move
G4 P200			; wait >140ms
G1 H2 X-18 F4800	; medium velocity move to y-20 The move needs to be >400steps made at a "medium speed", I think RPM > 10
G4 P200

; Homing
M400
M913 X10              	;lower current to x
M201 X500             	;lower acceleration
M566 X50              	;lower jerk
;M350 X16 I0
M915 X S-50 F0 H200 R2  ;set high sensitivity
;
G4 P200			;wait
G1 H1 X330 F6000 	;home
G92 X300		;set x coordinate to max

; Restore Settings
M400 
M913 X100		;> full current
M201 X9000		;acceleration
M566 X900		;jerk
M915 X S3 F1 H400 R0    ;set sensitivity and disable reports

4 questions:

• Any ideas on what shorted the Y axis twice?

• How can I avoid unreliable stallguard behaviors on the 2209's? (re: current & sensitivity settings in the x homing code)

• How can I use spreadcycle quietly with a moons motor like the MS17HA2P4100? (spreadcycle is noisy)

• Can the spreadcycle performance of the 2209 (duet 3 mini 5) not match the performance of the 2660 (duet 2) in noise?

@oliof

This and the previous board were/are active cooled with a noctua fan that's blowing directly across the back and front of the driver side of the motherboard.

The stepper driver has never reported an overtemp, but I agree - it's a lot to be using. Either way, I had the same issue with lower current motors.

My current suspicion is that I'm damaging the 2209's stallguard circuitry or putting it in a state where it cannot be used for a while.

One thing I have found that helps (prevent "short to vin" or "short to ground") is to raise the current of the offending axis slowly before sending any movements. So, for example, I have placed a 200 ms dwell/pause/wait after adjusting it to ~50%, then raising it to 80-100% with another pause after). Still not a explanation/solution, but it works better than anything else I've come up with.

@DocTrucker

Board is grounded along with the frame, but the culprit stepper hasn't ever been truly connected to ground or strapped to the case. I have tried to see a rise in voltage across the motor shaft and frame(ground), and I cannot. For what it's worth, the air in the room is usually >50% RH.

@droftarts

I suspected as much, but I've had this issue with very low inductance motors too (still high current, but less than 2A). Here is an example of one such motor:

WO-417-15-08. Inductance is <1mH, and it has an extremely low detent torque, meant for silent operation.

@oliof

This and the previous board were/are active cooled with a noctua fan that's blowing directly across the back and front of the driver side of the motherboard.

The stepper driver has never reported an overtemp, but I agree - it's a lot to be using. Either way, I had the same issue with lower current motors.

My current suspicion is that I'm damaging the 2209's stallguard circuitry or putting it in a state where it cannot be used for a while.

Update 2. I was fine for a while, but I just swapped in a large motor and set the Y axis driver to 1900 mAmps - and I think I fried the stepper driver, or part of it - stealthchop doesn't work while spreadcycle does. I had zero issues moving the motor around in stealthchop a few times, and found that I needed a very low sensitivity to avoid false stall reports w/ stallguard. I cannot figure out what I'm doing wrong, but I feel like I'm missing something obvious. This is a different duet 3 mini 5+ from the original board (w/ 2 fried drivers). Any input here is greatly appreciated.

XY motors are now both < 3mH inductance

When I tried a 0.7mH motor on the X, it reported a short notification immediately - motor was fine via my fluke multimeter. I can't explain this either. Ditched that motor for a 2.8mH SanMotion 0.9 stepper that has given me zero issues.

I'm running 3.5 rc2

Here's the homing gcode that I think killed the stepper driver:

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Homing
G91                    ; relative motion
M400
M913 Y50               ; CURRENT       <<<
M201 Y600              ; acceleration
M566 Y5                ; jerk
M915 P0 S80 F0 H200 R2 ; SENSITIVITY   <<<
M400
;
G1 H1 Y180 F1600       ; home
M18 Y                  ; y off

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Stealthchop Tuning
M569 P0 D2             ; > spreadcycle 
G4 P400                ; wait
M569 P0 D3 V0          ; > stealthchop
M400                   ; (clear)	
M913 Y100              ; > full current
M201 Y3000
M566 Y5 
M17 Y                  ; y on
G4 P400                ; wait to allow driver to initialize parameters
; 
G1 H2 Y-0.1 F600       ; tiny move
G4 P200                ; wait >140ms
G1 H2 Y-18 F4000       ; medium velocity move to y-20 The move needs to be >400steps made at a "medium speed", I think RPM > 10

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Restore Settings
M400 
M913 Y100              ; > full current
M201 Y12000            ; accel
M566 Y600              ; jerk
M915 Y S80 F1 H400 R0  ; set sensitivity and enable reports
M400
G4 P200                ; wait
G92 Y145               ; set y coordinate

Quick update - I tried decreasing the speed of homing on the Y axis, and so far, no more short reports. A sharp stall paired with the Y being a high current 1.8 degree motor that is geared down 1:2 leads me to believe I was back-emf spiking the 2209, causing a short detection. This is mentioned as a concern on page 45/end of section 6.5 in the 2209 datasheet as a possible problem. The motor was set to home at F6000, which would make for I believe 17k usteps/s. To me, this seems like more than is expected for a stallguard 4.0 move. Switching it to half that (F3000) has prevented further short notifications. If another short occurs, I'll follow up.

Just replicated the "short to vin" with a new motor and board using the same y axis home code. I immediately reset the machine, and the driver seems to be ok. The best hypothesis I had was static from belts, but I couldn't measure more than a mV rise with my multimeter on any motor component.

First, my Duet 3 Mini 5+ has lost two of its 2209 drivers to shorts, and I cannot identify the cause. I'm reliably getting "Phase A/B short to VIN" and unresponsive behaviors from drivers 0 and 3. I have ordered a replacement board, but I'm afraid I will ruin another driver or that the drivers were faulty.

The culprit printer is a Cartesian machine using a meanwell 24V supply (23.5V). Pictures of the wiring and the printer are attached. The motors are as follows:

X axis: Moons MS17HA2P4100 (11.2mH inductance: set to 800mA, rated for 1A)
Y axis: StepperOnline 17HS19-2004S1 (3mH inductance: set to 1200mA, rated for 2A) <axis that is shorting
Z axis: Moons unlabeled (integrated leadscrew motor from ~2014) (~9mH inductance: set to 600mA, don't know rating)
E axis: Revo Hemera XS (pancake motor I'm assuming from LDO) (? inductance: set to 500mA, don't know rating)

I printed for a while with zero issues using spreadcycle (was noisy) and stealthchop (was quietish). In the process of setting up sensorless homing/tuning stealthchop and stallguard, I shorted the first driver (3; Y axis). I don't know how I did it, but here is the gcode (y axis homing) that ran immediately before that short:

G91                     ; relative motion

; Stealthchop Tuning
M18 Y                   ;y off
M569 P0.3 S1 D2         ;> spreadcycle 
G4 P200                 ;wait
M569 P0.3 S1 D3 V0	;> stealthchop
M400                    ;   (clear)
M913 Y100               ;> full current
M17 Y 			;y on
G4 P200			;wait to allow driver to initialize parameters
;
G1 H2 Y-0.1 F1000	;tiny move w report
G4 P200			;wait 200ms (>140ms)
G1 H2 Y-18 F4800	;medium velocity move to y-18 w report
G4 P200                 ;wait

; Homing
M400
M913 Y50                ;lower current to y 
M201 Y500               ;lower acceleration
M566 Y60                ;lower jerk
M915 Y S-10 F0 H200 R2  ;set high sensitivity   
;
G4 P200			;wait
G1 H1 Y180 F5000        ;move to Y axis endstop w report
G92 Y170		;set coordinate to Y max
M400
G90                     ;absolute motion
G1 H2 Y165 F1200        ;move away from max to allow X movements

; Restore Settings
M400
M913 Y100               ;% current
M201 Y9000              ;acceleration 
M566 Y900               ;jerk 
M915 Y S10 F1 H400 R0   ;set sensitivity & disable reports

Here is the relevant bit of my config file for motors and such:

; Drives
M569 P0.2 S0 D3 V0                                 ; physical drive 0.2 goes forwards
M569 P0.3 S1 D3 V0                                 ; physical drive 0.0 goes backwards
M569 P0.4 S0 F12 Y5:0 D3 V80                       ; physical drive 0.4 goes forwards
M569 P0.1 S0                                       ; physical drive 0.1 goes forwards
M584 X0.2 Y0.3 Z0.4 E0.1                           ; set drive mapping
M350 X16 Y16 Z16 E16 I1                            ; configure microstepping with interpolation
M92 X177.78 Y177.78 Z400.00 E397                 ; set steps per mm
M566 X900.00 Y900.00 Z1200.00 E120.00             ; set maximum instantaneous speed changes (mm/min)
M203 X19200.00 Y19200.00 Z2400.00 E2400.00         ; set maximum speeds (mm/min)
M201 X9000.00 Y9000.00 Z2400.00 E250.00              ; set accelerations (mm/s^2)
M906 X800 Y1200 Z600 E500 I10                       ; set motor currents (mA) and motor idle factor in per cent
M84 S1                                             ; Set idle timeout

; Axis Limits
M208 X0 Y0 Z-3.5 S1                                   ; set axis minima
M208 X301 Y171 Z180 S0                             ; set axis maxima

; Endstops
M574 X2 S3                                         ; configure sensorless endstop for high end on X
M574 Y2 S3                                         ; configure sensorless endstop for high end on Y
M574 Z1 S3                                         ; configure sensorless endstop for low end on Z
M915 X S3 F1 H400 R2                               ;set sensitivity   
M915 Y S10 F1 H400 R2                              ;set sensitivity 
M915 Z S3 F1 H400 R2                               ;set sensitivity   

After I started getting the "Phase B short to Vin" warning, I suspected the motor and immediately ordered a replacement motor. After getting the replacement, I set up the Y axis on driver 0.0, which was the unoccupied driver. This motor has an integrated harness, so the wires were new too, and I test each harness before connecting to the duet. Same thing happened - that homing code fried the Y axis driver after 3 or 4 runs (motor moved fine).

Second, I have figured out the hard way that the 2209's do NOT like my (relatively) high inductance moons motors on spreadcycle. They are noisy and no set of hysteresis, blanking time, or other variables has rendered them silent. For others who may read this: it is probably best to avoid high inductance motors if you want to print fast and quiet on the 2209's. I have also had a lot of trouble with stallguard with this particular printer; I'm guessing sensitivity settings vary depending on Vin. Maybe the spreadcycle-dependent stallguard on the 2660s (Duet 2) is more resilient to fluctuations induced by loads like a bed heater?

Here is the homing code for the X axis, which has the highest inductance motor: (please note the high sensitivity and low current that I have to use)

G91                     ; relative motion

; Stealthchop Tuning
M18 X			;x off 
M569 P0.2 S0 D2         ; > spreadcycle 
G4 P200                 ; wait
M569 P0.2 S0 D3 V0	; > stealthchop
M400			; (clear)	
M913 X100   		; > full current
M17 X 			; x on
G4 P200			; wait to allow driver to initialize parameters
; 
G1 H2 X-0.1 F1000	; tiny move
G4 P200			; wait >140ms
G1 H2 X-18 F4800	; medium velocity move to y-20 The move needs to be >400steps made at a "medium speed", I think RPM > 10
G4 P200

; Homing
M400
M913 X10              	;lower current to x
M201 X500             	;lower acceleration
M566 X50              	;lower jerk
;M350 X16 I0
M915 X S-50 F0 H200 R2  ;set high sensitivity
;
G4 P200			;wait
G1 H1 X330 F6000 	;home
G92 X300		;set x coordinate to max

; Restore Settings
M400 
M913 X100		;> full current
M201 X9000		;acceleration
M566 X900		;jerk
M915 X S3 F1 H400 R0    ;set sensitivity and disable reports

4 questions:

• Any ideas on what shorted the Y axis twice?

• How can I avoid unreliable stallguard behaviors on the 2209's? (re: current & sensitivity settings in the x homing code)

• How can I use spreadcycle quietly with a moons motor like the MS17HA2P4100? (spreadcycle is noisy)

• Can the spreadcycle performance of the 2209 (duet 3 mini 5) not match the performance of the 2660 (duet 2) in noise?

@Phaedrux

I love this idea! Thank you. Going to try the tandem.

@Phaedrux

I could do that. And I've thought that it would fix my issue. It's not simple to do. But it would mean the edge temp of the bed isn't correct, and it's not addressing the underlying problem - I can't use a bed that's lagging. That should be possible, right? All beds lag to some extent. I'm just outside the tolerance of M303 as is.