DWC speed monitor

[Arminas]

DWC shows maximum travel speed 141.1 mm/s, although it should be 200 mm/s. Is it just the maximum speed that DWC can show or something is wrong with my config and I can not reach 200 mm/s?

[jay_s_uk]

@Arminas is it a corexy and moving diagonally?

[Arminas]

@jay_s_uk yes

[jay_s_uk]

@Arminas then thats the speed its travelling
RRF limits the diagonal moves so the motors are travelling at the same speed. So if you max speed is 200mm/s in X or Y (as both motors are being used), the max diagonal would be the root of that 0.707x that which in this instance is 141.1mm/s
Its a limitation of the firmware as it currently stands

[Arminas]

@jay_s_uk so, if I will set the travel speed to 300 mm/s, it will actually be 173.2?

[Arminas]

@jay_s_uk and I also have to increase the maximum speed in config?

[jay_s_uk]

@Arminas sorry, its not root but 0.707 times the max speed. So 300 would 212.1mm/s
So yes, if you want to print at 200mm/s on the diagonal you'd have to set you max speed to 1.4x that speed

[Arminas]

@jay_s_uk I have noticed that my maximum speed on config was 10500 mm/min (175 mm/s). I have increased it to 18000 mm/min (300 mm/s) and now the set travel speed and actual travel speed is the same - 200 mm/s. Well, maybe it is not completely diagonal movement, idk. It just moves across the build plate from one point to another.

Also, isn't 200 mm/s travel speed too much? on the corexy? I increased it because of the oozing of PETG. And it still oozes a bit.

[jay_s_uk]

@Arminas i wouldn't say 200mm/s is a lot for a coreXY. i can move at 1200mm/s on mine and maintain position (although couldn't print that fast)

[dc42]

@Arminas said in DWC speed monitor:

@jay_s_uk and I also have to increase the maximum speed in config?

Yes. CoreXY machines are capable of higher speeds in X and Y directions than 45deg diagonal moves, because both motors contribute to pure X or pure Y motion, whereas just one motor is used to perform diagonal motion. RepRapFirmware makes use of this to maximise performance. Some other firmwares (e.g. Klipper) don't. So on a CoreXY machine, in RRF the maximum XY speeds and accelerations should be set to 1.4 times the values that you would use in Klipper.

If for some reason you want all moves in the XY plane to have the same max speed then you can use the maximum travel speed in your slicer to enforce this; and if you want all moves in the XY plane to use the same acceleration, you can use M204.