Setting stepper parameters from terminal

Software / Firmware General
1

This question applies to my LR4 and Primo, but probably any other machine that uses Marlin in combination with the SKR 1.3 control board.

I believe that in the typical Marlin code that is used on the MPCNC, there are maximum speeds set within the control code. Generally, these are probably fine, but, for surfacing, especially when taking shallow DOC, it might be desirable to increase those limits.

So, I guess my question is two parts.

  1. Is there a terminal command that will provide the current values for the speeds, especially X and Y?
  2. Is there a terminal command that can be used to increase (or decrease) the limits? I presume there would be a command to save the parameter change.

At this stage, since my LR4 is basically working, Iā€™m not too interested to go back to the basic code for the SKR 1.3, edit it and upload it. Although Iā€™ve done this in the past, the process never seems to go well, so, doing changes from the terminal is much more appealing.

The terminal is easy to use with the TFT 35 display in touchscreen mode.

2

Marlin commands referenceā€¦

M503

M201, M203, M204, M205, (M210)

Save with M500

Note that Max Feedrate and Max Acceleration are inter-related, and changing one can affect how the other works, and either one can cause missed steps if not done correctly.

1 Like
3

Thanks. This will be helpful.
One thing that is not exactly clear is how these commands work when there are dual stepping motors on an axis, e.g. z1, z2 and y1, y2.

My intuition tells me that simply adjusting the y value with M203 Y*** is not going to be sufficient it only sets one of the motors.
Or, maybe the firmware is smart enough to know that setting ā€œyā€ means both of the y motors?

4

You might find this reference useful for what gcode commands you can use.

Settings are per axis, not per motor. I canā€™t think of any situation where youā€™d want each Y motor moving at different rates.

5

Good to confirm this. Iā€™m no firmware expert but just wanted to confirm that by setting the X and Y speeds, Iā€™ve got it covered even though there are two Y motors on the LRx units.

And, thanks for the link to the Marlin reference.

6

Itā€™s the right thing to do - if in doubt:ask.

An ounce of prevention is worth a pound of cure as granny used to say. Nobody is going to haze you for asking a ā€˜dumbā€™ question or tell you to RTFM, itā€™s a better community than that here.

For myself I do love seeing what people make so I can steal their ideas be inspired so please come back with the cool stuff you make when you get going.