G80 and G87 - What really happens?
So I know G80 is the autocalibration that runs before every print...What is this looking for particularly before every print. Is it just to ensure the axis is still aligned, or is it looking for zpoint height as well?
I ask because of the G87 code. This is the code needed to ensure Live Z is saved after first layer calibration prints, and to get rid of the message on the printer. Does this code also tell it to check/adjust live Z each time? I had it in my standard starting Gcode for every print. Any negatives to having this?
I was using the G81 command to view Z reference point measurements after various prints and saw a moderate difference between each one. Wondering what the baseline is and if the G87 was causing it to check and cause the variation each time. I make sure everything is cool and bed warmers away from PINDA during G80 calibration.
Re: G80 and G87 - What really happens?
Bump
I assume someone here must know this answer. Really trying to figure out best methods to run code and how the printer calibrates.
Re: G80 and G87 - What really happens?
The G87 code simply tells the firmware that the printer has been calibrated and that the "Live Z Adjust" value can be used.
G80 may be called at the start of the GCode and this simply sets the bed height in respect of the probe position at the 9 points and then applies and manual bed level correction to those values.
It is not essential to use G80, but in cases where the printer has been power-cycled it should be used. Therefore it is a lot safer to use it all the time.
It will also catch any differences which occur due to bed/ambient temperatures.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: G80 and G87 - What really happens?
So are these numbers averaged? I have 2 screenshots here of the values read. The beginning and middle numbers differ across each line but the final numbers at the end are relatively close. Are these the final numbers used?
