Mesh Bed Leveling Quirk
I recently bought and built a M3S+ printer and absolutely love it. After spending some time getting the first layer z dialed in I am amazed at the quality of the prints I am getting off this machine. It has however developed a little quirk that I am curious about. After reading a lot of the posts in this forum I changed to 7x7 bed leveling. Now when I start a print the pinda probe starts at the left front corner, does it's little up and down hops a few times and then goes to the next probing location. It repeats this at all seven locations along the front edge of the bed and then moves back to start on the second row. At the second probing location in the second row, occasionally, the printer head will do it's usual up and down hops but will then suddenly bounce up about 10 to 15 additional mm higher, come right back down and repeat the up and down hops. The printer will then continue with probing all the remaining points and start printing. The printer only does this when probing that one location and doesn't do it for every print. I've noticed that it usually does this for the first print after the Printer has sat idle for some time. It seems to have no affect on the quality of the print so I'm not really concerned about it. I am just curious as to what is causing this to happen. Thanks.
It's normal.
It is designed to retry when a measurement comes out borderline. A bit of smudge under your plate can cause this type of behavior - so think of it as a sign to schedule that plate and bed for an inspection and future cleaning - but that behavior is not an error or a problem to worry about.
RE: Mesh Bed Leveling Quirk
Thanks for your reply. I suspected the reason was along those lines but was not able to find any information to explain what/why the printer was doing that.
RE: Mesh Bed Leveling Quirk
Have you checked your Live-Z value, IIRC it HAS to be between 0 and -2.0mm, but if it's getting toward one of these limits, that may cause the firmware to have to retry many more of the points. If you're somewhere in the middle of the range then it's either muck between the steel sheet and the bed or very minor distortion in the steel sheet (this minor distortion usually isn't at all significant, even if the printer has to retry a few points).
RE: Mesh Bed Leveling Quirk
No, my live-z is well within limits and the printer has been working just fine. Best prints I've ever gotten off a 3D printer. After Dan's reply I did remove my build plate and wiped down both the bottom of the plate and the heater bed even though I couldn't see anything on either. In any case, since then the printer has not made that second probing attempt at that one location.