Duet 3 Mini 5+ sensorless homing configuration

[flobler]

@Veti

I spent the past couple of hours trying to find the correct values for sensorless homing but got no further.

For this purpose I tried to home X only to see if I could get it home correctly, therefore only adjusted homex.g

General:

• Motor peak current 1a
• M906 X500
• config.g
• homex.g

Values I adjusted in homex.g throughout my tests:

• M913 (range of adjustment 30-80%)
• M915 S value (range of adjustment 1-3)
• G1 F value (range from 4000-10000)

Procedure:

1. Set values and upload homex.g
2. Move X 100mm away from home point
3. Try Homing
4. Stop

How I changed values:

a) Start with

• M915 S3
• G1 F10000
• M913 X80 Y 80

b) Adjust M915 to S2 and S1, try homing for each value

c) Lower G1 F by 1000

d) Repeat b)-c) until G1 F4000 is reached

e) Lower M913 by 10

f) Repeat b)-e) until M913 X30 Y30 is reached

g) End with

• M915 S1
• G1 F4000
• M913 X30 Y30

I hope this makes sense... So far all of those tests gave me a crash.

Are my jumps on the values too big? Is there something else I am forgetting with those tests?

[Veti]

i havnt gotten around to testing sensorless homing on the mini 5
i think you are the first person to try.

[Veti]

i just tried with the highest sensitivity and could not get the sensorless homing to trigger.

@dc42 any suggestions?

[dc42]

The critical point in the doc on stall detection for the Duet 3 Mini is this:

Additionally, the TMC2209 stepper driver used in Duet 3 Mini 5+ (and Duet 3 Tool board TOOL1LC once stallGuard is implemented in firmware), features stallGuard 4. This is optimised for operation with stealthChop, while its predecessor stallGuard 2 (TMC5160 and TMC2260) works with spreadCycle. You will need to adjust the speed at which stealthChop changes over to spreadCycle. This is set by M569 V parameter. The default is 2000.

You will need to reduce the V parameter (at least during homing) so that at the speed of the homing move, the driver is operating in stealthChop mode. By default it is only in stealthChop mode at very low speeds, too low for homing moves. See the M569 command.

[Veti]

@dc42

my steppers are running in stealhchop with up to 120mm/sec, still it would not trigger

[dc42]

Confirm you are using firmware 3.2RC2 ?

What does M569 P# report, for values of # corresponding to the drivers for the axes you are trying to home?

[Veti]

@flobler
can you also with stealthchop.

@dc42 i configured back, and running a print, but these are the settings that i am running all the time
30/12/2020, 20:19:44 M569 P0
Drive 0 runs forwards, active low enable, timing fast, mode stealthChop, ccr 0x00053, toff 3, tblank 0, tpwmthrs 30 (125.0 mm/sec), pwmScaleSum 222, pwmScaleAuto 27, pwmOfsAuto 64, pwmGradAuto 22, pos 584

Drive 1 runs forwards, active low enable, timing fast, mode stealthChop, ccr 0x00053, toff 3, tblank 0, tpwmthrs 30 (125.0 mm/sec), pwmScaleSum 73, pwmScaleAuto 0, pwmOfsAuto 57, pwmGradAuto 19, pos 611

[dc42]

Please post your config.g file again, because the M569 commands in the one you posted earlier do not maintain stealthChop mode up to 120mm/sec.

[jay_s_uk]

we've had good success with sensorless homing on the LPC port using D3 V40 after each M569 for the axis being homed.
we typically suggest running

M915 P0 S-63 H10 R1 ; Set very sensitive stall detect
M574 X1 S3 ; configure endstop for stall detection
G1 X200 H1 ; Should stall pretty much immediately

to ensure that everything is working correctly. You can then tweak as required to work on your system

[flobler]

@dc42 that was me who posted the config

I can confirm that I am running 3.2RC2. I will reduce the V parameter and try again. I will report back.

Thanks for the help!

[Veti]

@jay_s_uk said in Duet 3 Mini 5+ sensorless homing configuration:

we've had good success with sensorless homing on the LPC port using D3 V40 after each M569 for the axis being homed.
we typically suggest running

tried it again with your settings and the motors keep grinding away

[jay_s_uk]

@Veti even with setting S to -63?
If it doesn't immediately trigger that means there's something not right somewhere.
I can maybe have a go with it this morning with mine.
Will report back

[Veti]

i even tried with -64

[jay_s_uk]

I can also confirm that sensorless homing does not appear to be working on the mini5+ with RC2.

[dc42]

@jay_s_uk said in Duet 3 Mini 5+ sensorless homing configuration:

I can also confirm that sensorless homing does not appear to be working on the mini5+ with RC2.

It worked for me during testing. I will try to find the configuration that I used.

[gregsaun]

Thanks everyone for helping @flobler , he is working on an official Bear config for the Mini 5+

[flobler]

Yeah, thanks for the help everyone, really appreciated!

I just wanted to add that I am using version 0.4 of the Mini 5+. I also tried all the above and sensorless homing did not work for me. Motor was operating in stealthChop.

[flobler]

Actually, that combo got it to stall the first time I tried homing X. It stalled immediately when trying to move.

homex.g config.g

What is weird though is that it did not work afterwards again. I need to power cycle the printer (emergency stop did not do it) for it to work again and then again it only works on the first try. This worked 5/5 times so far.

[dc42]

Bear in mind that you need to execute a tuning procedure when using stealthChop mode.

[flobler]

Thanks! Just found the docs on that. Will apply and report back.