Hello,
I have built a prusa i3 mk2 clone from scratch, following Thomas Sanladerer
series. and am experiencing trouble with the bed leveling (inductive) probe. It seems to be highly sensitive to heat, since running a repeatability test on the probe with the nozzle and the bed being hot results in a standard deviation much higher than the test with those parts being at room temperature (0.09mm vs 0.01mm). The width of the hysteresis is also much larger when heated (i.e. the probe "untriggers" way higher above the triggering height when the heating elements are hot). Thomas Sanladerer tackled this issue in one of his
videos, stating that this is a common issue. However, the repeatability in our case is much worse than in the video. This results in a very different home position each time I run a G28 command when the heating elements are hot, and the printer is therefore unable to reach a correct height when printing, and just hovers a few millimeters above the bed.
Looking this up on google, I couldn't find anyone with a similar problem, and Tom didn't seem to be bothered at all, even though he bought the cheapest sensor available on the market. Therefore I am wondering if there may be other factors causing this fail, or if I just own a defective sensor and should buy another.
The inductive sensor is
this one, and the heatbed is an
AptoFun mk3, which is placed bare aluminium side up to have a flatter print surface.
Any thoughts on this?
Thanks in advance.
Edited 1 time(s). Last edit at 07/24/2019 08:51AM by bathal.