Duet3 6CH + 3CH expansion board - Missing steps.

evomotors

My setup:
Duet3 6CH
3CH expansion board
RPi4
All running latest official firmware.

I'm running BMG extruder with 1/16 micro-stepping mode. Print speed is 80mm/s. Extruder is connected to the expansion board using shortest possible cable (cable sold with the board by filastruder). How come board is missing so many steps?

Isn't 3CH Expansion board marketed for running multiple extruders?

Phaedrux

Please post your config.g

evomotors

config.g.txt
Here is it.

evomotors

@Phaedrux I hope it's my mistake in the configuration, but it doesn't look like it.

deckingman

@evomotors Which firmware version are you using? If by "latest official" you mean 3.1, then the step pulse frequency for expansion boards is appallingly bad. I'm told this is fixed in 3.2 but personally, I'm waiting for that to become a stable release before I try it. The only thing that surprises me is why so few people have noticed this problem.

dc42

@evomotors, please upgrade to 3.2RC2, or wait a few days for the release of 3.2 stable.

evomotors

@deckingman said in Duet3 6CH + 3CH expansion board - Missing steps.:

@evomotors Which firmware version are you using? If by "latest official" you mean 3.1, then the step pulse frequency for expansion boards is appallingly bad. I'm told this is fixed in 3.2 but personally, I'm waiting for that to become a stable release before I try it. The only thing that surprises me is why so few people have noticed this problem.

I guess not everyone who is using expansion and or tool boards running fast machines, or not running 1/16 micro-stepping. If I reduce to 1/8 it will be fine on printing speed of 80mm/s, but I will lose extruder accuracy, also 80mm/s is the slowest I ever print.

evomotors

@dc42
Is it really going to be out in a few days?

dc42

@evomotors said in Duet3 6CH + 3CH expansion board - Missing steps.:

@dc42
Is it really going to be out in a few days?

It's out already.

evomotors

@dc42
Woo hoo! I will be upgrading in about an hour.

deckingman

@evomotors Just be aware that RC= Release Candidate. That's not the same as a final, stable, release. Personally, I'll continue to wait.

Phaedrux

@deckingman said in Duet3 6CH + 3CH expansion board - Missing steps.:

@evomotors Just be aware that RC= Release Candidate. That's not the same as a final, stable, release. Personally, I'll continue to wait.

Wait no longer.

https://github.com/Duet3D/RepRapFirmware/releases/tag/3.2

deckingman

@Phaedrux Confused now . DC wrote earlier today quote "please upgrade to 3.2RC2, or wait a few days for the release of 3.2 stable."

Phaedrux

I guess things progressed more smoothly than anticipated?

evomotors

@deckingman
Well, 3.2 is official stable now.

deckingman

@evomotors That's the quickest few days I've ever come across Let me know if it fixes your problem - then I'll give it a shot myself.

evomotors

@dc42 said in Duet3 6CH + 3CH expansion board - Missing steps.:

@evomotors said in Duet3 6CH + 3CH expansion board - Missing steps.:

@dc42
Is it really going to be out in a few days?

It's out already.

Issue is not fixed!

M122 B1
Diagnostics for board 1:
Duet EXP3HC firmware version 3.2 (2021-01-05)
Bootloader ID: not available
Never used RAM 154848, free system stack 158 words
HEAT 90 CanAsync 94 CanRecv 84 TMC 30 MAIN 305 AIN 257
Last reset 01:37:18 ago, cause: power up
Last software reset data not available
Driver 0: position 0, 80.0 steps/mm,  standstill, reads 36849, writes 11 timeouts 0, SG min/max 0/0
Driver 1: position 226160, 344.0 steps/mm,  ok, reads 36831, writes 32 timeouts 0, SG min/max 0/1013
Driver 2: position 0, 80.0 steps/mm,  standstill, reads 36855, writes 11 timeouts 0, SG min/max 0/0
Moves scheduled 15696, completed 15694, in progress 1, hiccups 380
Next step interrupt due in 3606 ticks, enabled
VIN: 24.6V, V12: 12.3V
MCU temperature: min 43.8C, current 44.0C, max 44.2C
Ticks since heat task active 228, ADC conversions started 5838220, completed 5838219, timed out 0
Last sensors broadcast 0x00000000 found 0 232 ticks ago, loop time 0
CAN messages queued 35, send timeouts 0, received 68218, lost 0, free buffers 36

evomotors

Should I change something else in the config? CAN bus timing?

dc42

I presume you are referring to the hiccup rate. It looks like the hiccup rate has reduced from 1 hiccup every ~5.6 moves to 1 hiccup every 41 moves. That's a seven-fold improvement!

Hiccups are not lost steps, they are delayed steps. The delay may be only a few microseconds.

I am still a little surprised that the hiccup rate is not lower. What speed are you printing at, and what nozzle size are you using?

evomotors

@dc42 said in Duet3 6CH + 3CH expansion board - Missing steps.:

I presume you are referring to the hiccup rate. It looks like the hiccup rate has reduced from 1 hiccup every ~5.6 moves to 1 hiccup every 41 moves. That's a seven-fold improvement!

Hiccups are not lost steps, they are delayed steps. The delay may be only a few microseconds.

I am still a little surprised that the hiccup rate is not lower. What speed are you printing at, and what nozzle size are you using?

BMG direct drive extruder, 1/16 micro-stepping
0.4 nozzle
Current print speed 40mm/s perimeters (looks beautiful), 80mm/s infill (look like crap)

When extruder connected directly to Duet3 I print perimeters and infill at < 200mm/s without issues.