Hi,

I've been wondering about the marlin's skew formula here:

* - Compute AB : SQRT(2*AC*AC+2*BD*BD-4*AD*AD)/2
* - XY_SKEW_FACTOR : TAN(PI/2-ACOS((AC*AC-AB*AB-AD*AD)/(2*AB*AD)))

If I understand correctly, first we need to get AB computed variable, then we would use the AB again for the skew factor. I did copy the above formula directly to openscad and echo the results. It was out of marlin's acceptable range of -1 to 1. I think the result was somewhere 1.340 or something. I really forgot. While the eeprom results was way below that I think -0.004058 (just random but I think should look like this).

I'm asking here because I don't want to keep on reflashing the board if there's any skew changes.

How can I get a proper results that can be used by marlin?

Also, I think it would be great if the marlinfw.org has this calculator where we just insert the desired values.

Thank you in advance