Live Z adjust different on each side
Do you find the optimum Live Z adjust to be different on each side of the same steel sheet? I have one sheet where -1.080 works great on one side, and -1.130 on the other. One possible explanation is that the PEI is thinner on one side than the other, as the calibration isn't measuring the surface of the sheet, it's measuring (I think) the magnets underneath. This is a sheet that I have used a lot (probably 5000+ hours) and I only noticed this when I decided to recalibrate it recently.
Side note: my test procedure is to print a 50x50x0.2 square. Too little squish and the lines separate if I pull on the square after printing it. Too much squish and I get rucked-up waves in the print. A difference of as little as 0.02 can change from one to the other.
RE: Live Z adjust different on each side
Do you find the optimum Live Z adjust to be different on each side of the same steel sheet?
yes, i faced it too.
you have to find the sweet point that it's "fine" for both sides. In the calibration menu you can find also the "bed level correction" that can be helpful to compensate that variation.
I'm not an expert. Ma parlo anche italiano 😉
RE: Live Z adjust different on each side
The pinda measures the distance to the sheet, not to the magnets (as far as I understand anyway). So, your idea that it is a variation in the PEI thickness makes sense to me. What you can do, is store two versions of the sheet in the printer, like SmoothA and SmoothB and set the Live Z for each one independently. Then just select the sheet side you are printing on. Use a marker to note the side on the sheet, in an unprintable area.
RE: Live Z adjust different on each side
And I use the exact same method for live-Z, except that I use a 30mm square. Very fast and easy, about 2 min per print, and I removed the cooldown gcode so that I can make adjustments and immediately print another square without another re-heat cycle. Also to do a 'cold' live Z adjust (like on a new sheet), what I do is take a piece of regular printer paper and put it under the nozzle, then use Settings-->Live Z Adjust to lower the nozzle until the paper just starts to drag. This is a good starting position, in my experience.