Maximum acceleration no effect after certain point? (M201)

smuellerch

Hello Community,

First time Duet user here...

I'm trying to find the limits of my printer. I would expect that if I set the acceleration too high, I'll start losing steps. This doesn't appear to be happening.

I've wrote a little macro that just moves the head in a triangle. It runs just fine despite the ridiculous acceleration values:

; Max speeds
M203 X42000 Y42000

; Acceleration (this should not work)
M201 X10000000 Y10000000

; Jerk
M566 X12000 Y12000

G90 ; Abs positions

; Go to start point slowly
G0 F3600
G0 X20 Y20

G0 F1000000	; Super fast so that we are limited by the max settings

G0 X20 Y20
G0 X200 Y20
G0 X120 Y200
G0 X20 Y20

Setting M201 it to small values visibly reduces acceleration, so it isn't completely ignored.

I only have this problem with M201. Setting Jerk or max speed very high does indeed cause lost steps.

Running FIRMWARE_NAME: RepRapFirmware for Duet 3 Mini 5+ FIRMWARE_VERSION: 3.4.4 ELECTRONICS: Duet 3 Mini5plus Ethernet FIRMWARE_DATE: 2022-10-20 16:18:28

dc42

@smuellerch acceleration is also limited by M204, so check what M204 values are set. The default is 100000 AFAIR.

smuellerch

@dc42 Thank you!

That was it. M204 defaults to 20'000 mm/s^2. Starting to lose steps at 24'000 mm/s^2. Not bad for an Ultimaker 2 that's close to 10 years old.