@infiniteloop if it is a hardware limit I am bumping up against is what I am trying to ascertain. if it is a hardware issue I will need a different board, if it is some config issue, then I do not

@infiniteloop
this is the best I have received and it is configured completely differently. this uses an 8 pin connector or a can bus. but the Viscotec uses a 4 pin setup, two to live and neutral 24V, and 2 to the motor pins of the duet. it uses the duet's motor pin signal to command an internal driver witch runs the servo.

EN_2250_BX4_CXD_DFF (not our configuration).pdf

@phaedrux
m115
FIRMWARE_NAME: RepRapFirmware for Duet 3 MB6HC FIRMWARE_VERSION: 3.4.0 ELECTRONICS: Duet 3 MB6HC v1.01 or later FIRMWARE_DATE: 2022-03-15 18:57:26
the problem is not with the motor but with the signals from the duet.

@infiniteloop we have had a problem with the motors before, but they will not give or don't have a datasheet for the motors as far as I am aware. however the problem is for sure with the signals coming from the duet board having gaps in the duty cycle

@gloomyandy

config (1).g

the motor is a bit weird but it is not important for this problem. it will be difficult to get the Motor specs

Hello I am running a duet 3 and trying to go to F16000 for one of my extruders. I have a two in one out extruder so each motor is rated for F8000 with no micro stepping.

when I run the motors they ran oddly so I looked at the duet's signals form the pins to the motors and noted at about F13710 it would begin to have warped duty cycles

here is a photo of a G1 E1000 F8000

and here is a photo of G1 E1000 F16000

I am not sure why it is doing this, is this a limitation of the drivers? am I approaching the limit of the TMC5160? is there a demon eating my pulses?

any help will be appreciated

@t3p3tony Thank you for all your help, I do not think I can get the datasheet, if I ever do I will post it here.

to summarize the problem and solution for future readers:

I had an extruder motor for the printers at work that did not spin the correct amount at high speeds on all printers but one. it was a servo that took stepper motor signals from the servo pins to command the driver. it needs a full step signal to work.

although in the config we had turned micro stepping to full step, we had interpolation on, witch does a minor bit of micro stepping even if that motor is set to full step. the reason the one printer did not have this issue was because it was the only one running with the duet 2, which does not support interpolation unless the drive is set to x16 micro stepping. so with the same config it would run the motor properly

thanks for all the help everyone

@t3p3tony I am having trouble finding the datasheet, it is a different company that makes it so it may not be available.

@phaedrux so I think I have solved the problem

I looked at the motor config recommendations, and found that we had interpolation on for the M350 command. I turned it off and I could spin the motor at 13000 with the full 8.25 expected rotations.

now I want to verify I am understanding the problem fully and why this worked. because the duex still works and still has interpolation on. how could this be?

@t3p3tony
so when we asked for the motor specs it was revealed it is a servo with an internal driver that reads a stepper driver input. in the instructional video they plug it into a duet the same way, so it comes back to the weird signal from the board.

looking back at the scope it doesn't look like noise per say, but more like signals combineing/ cutting out at weird times.