Can M204 somehow change probe speed?

Running a Lowrider with SKR1.2 and dual endstop firmware. I was tuning in my endstops and decided to turn down the acceleration as my Lowrider is getting quite heavy. I did this by running M204 and changing T from 180 to 100 as it seemed like the other two parameters are only for printers (correct me if this is wrong).

I got it to an acceleration that looks good, saved with M500.

My problem is now my probing (G38.2) and homing my axis (G28) both seem to be much faster and putting in an F script does not seem to slow them down. Reverting back to M204 T180 also does not change the probe speed or the homing speed.

I read that I could adjust my max speed with M203 but would this not also effect my max travel speed during cutting operations?

Any idea what I might have accidently changed to make this happen?

No specific answer to your question but a couple of suggestions. Assuming you don’t have a bunch of settings saved that would be difficult to reenter, consider doing a factory reset (M502) and retesting. Getting back to a state where the problem is “solved” will help debug the problem.

I also noticed values in the firmware for setting homing and probing speeds. Here are the defines pulled out. I’ve never used them, so I don’t know anything about them other than noticing them in configuration.h:

#define HOMING_FEEDRATE_Z  (4*60)


Brilliant, yeah I only have my endstop offsets setup with m500 so no big deal to re-enter them. I will give the reset a try thanks!

Would that clear anything that v1 might have loaded onto the board or would it only reset the stuff I have been sending to eeprom?

It only clears what you saved with an M500. On the flip side (and not related to your problem), if you flash new firmware, the old EEPROM settings are not cleared. This also means for setting you saved in EEPROM, changes directly in the firmware at a later date for the same values will not take unless a factory reset is done. More info than you asked for.

Makes sense, yeah I actually discovered that the last time I flashed the firmware. Panicked because I had not written down my endstop offsets but then happily discovered that they did not get over written
Thanks for the help!

M502 did the trick, I must have typed something in error. Thanks @robertbu .

I guess I should also ask, did I do it correctly by just changing T or should I also adjust P (printing acceleration) to smooth things out while its cutting. Does the machine consider a cutting operation “Printing”?

I’ve never used M204, nor played with acceleration in the firmware. As a guess, I bet ‘T’ maps to G0 moves and ‘P’ maps to G1, G2, and G3 moves. Maybe someone else on the forum that has more experience with acceleration can give you a definitive answer.

1 Like