why does bed leveling probe a point twice?
I've noticed lately that the mesh bed leveling that happens at print start time is probing 2 separate points 2x each. points #2 and #6 actually. any idea why it would do that?
RE: why does bed leveling probe a point twice?
It actually measure each point multiple times. Up to 5. If it looks to be stuttering, the assumption is the point measured was outside the expected range of values so it pauses, then measures again.
RE: why does bed leveling probe a point twice?
Hello!
It's been a while since last post, but still... @tim-m30, i guess that @rgordon0 didn't mean what you're explaining, since it's happening to me lately also: two or three of 49 points are probing twice: first it takes 3 quick samples on a certain spot, then extruder is lifted and lowered somewhat and probing is repeated. This happens, as i said, only ony two, three points, mostly on right side. Any clues why? I just did a complete service on my printer: did a lubrication, cleaning, factory reset and complete recalibration, but still happens. Prints are perfect, BTW...
RE: why does bed leveling probe a point twice?
@protoncek
Maybe a firmware timing problem. I would report this issue Prusa.
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.
RE: why does bed leveling probe a point twice?
Hm... well, could be... I'm using 3.9.0 RC3, but it was the same in 3.9.0 RC1. I'll flash back to 3.8.1 to see...
thanks for the tip!
RE: why does bed leveling probe a point twice?
If the probe encounters and error, it will raise and try again. This can happen due to vibration. If successive probes are successful, it will carry on. When Prusa first introduced fast probes, the printer would error out and do a Z calibration when this happened, which was really frustrating. If it pauses and carries on, it is working as intended.
If it is happening regularly, you can try repositioning the printer, or even moving it onto a solid floor to see if the problem goes away. If so, it might be that the fast probing generates a resonant frequency on your normal surface. Overall, I wouldn't worry about it.
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RE: why does bed leveling probe a point twice?
As i watch it now when i'm doing several short prints, printer always does re-calibration on same two spots, rarely on third one. Since it happens on first and second row, and 6th column (so, it's 6th and 9th point) i guess maybe bed is somewhat uneven in that location.
Leveling always ends OK, also prints are ok. So, as you said, i guess i shouldn't worry too much if it doesn't get worse.
RE: why does bed leveling probe a point twice?
Do check to make sure there are no errant bits of filament under the flexible sheet, and that there's no nozzle ooze that can throw calibration off.
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He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: why does bed leveling probe a point twice?
Hello,
i am having the same issue.
it started happening after i did the mk3s uprade.. i didnt notice it on mk3..maybe i missed it..i dont know...
did you find a solution ?
RE: why does bed leveling probe a point twice?
No, and to be honest i didn’t dig into it anymore. Since leveling always ends succesfully i’m not worried too much. It is interesting, though...