Polynomial Temp Compensation for Probes?

Kolbi

@evan38109 No worries at all on posts. The modified BMGm housing with BLTouch is working extremely well, I have a couple tweaks to make to the design files and then I'll post them. Just like the ones purchased through bondtech, mine were printed using MJF / Nylon.
On the Pinda, I never had major issues because I always did a probe warming routine to keep all measurements on an even temp offset. I had random problems with offset because of it - more noticeable with certain build plates then others. What was enlightening to me was the probe measurement disparities between runs - didn't think it would be that bad but the saw-tooth patterns above depict it - those metrics were derived over at least 5 runs.

For the BLTouch - it's totally great. No more offsets for different build plates, no temp comp, and reliable repeatability.

Cheers,
Kolbi

Phaedrux

@Kolbi said in Polynomial Temp Compensation for Probes?:

mine were printed using MJF / Nylon.

That's quite the hardware to have access to, or was it printed through a service? It looks quite nice.

Kolbi

@Phaedrux Hehe, not mine - it was sent off for mfg. I have to modify it slightly, tighten the pocket where the mosquito sits with a set-screw to make for a no-compromising tightness. Also thinking about adding part cooling ducts into the housing sections with just a replaceable air nozzle/deflector.

dc42

@Kolbi, the forthcoming 3.2beta firmware supports 2nd order temperature compensation for trigger height.

Kolbi

@dc42 Nice! How will the temperature offset/calibration process work?

dc42

You will have to work out the calibration manually as you have done already. Once you have worked out the first and second order temperature coefficients, you can enter them in the M558 C parameter, e.g.

M558 ... C0.01:0.005

Kolbi

@dc42 Thanks! Was just reading this as you replied:
Z probe trigger height second order temperature compensation is now supported. To use it, specify a 2-element array as the temperature coefficient, e.g. "M558 ... C0.01:0.0005"