Strange hops on bed leveling, just started recently  

RE: Strange hops on bed leveling, just started recently

If this is an MK3s then the black tops of the Z axis are wrongly mounted (upside down). Thus you can't properly calibrate Z.

RE: Strange hops on bed leveling, just started recently

Been that way since I built the printer back in September, and hasn't done that hopping when moving left until just recently. Is that what you think is causing the issue, or just something you noticed in the video?

Prints have been normal, even with the second "hop" as well.

RE: Strange hops on bed leveling, just started recently

Looks like it's just the left side that is upside down - i stripped one of the nuts when i was building it and replaced it, guess i put it in upside down.

RE: Strange hops on bed leveling, just started recently

if it helps as all, the reason it does that is because there's more variance in the measurement(s) than it expected. Is something loose causing your PINDA or extruder to tilt one way or the other when moving left or right?

Usually when I've seen this on mine (in a single spot, not an entire direction) it retries a few times and then yells at me, at which point I lift the build sheet to discover a stray piece of filament stuck under it...

RE: Strange hops on bed leveling, just started recently

The firmware will do that when the rapid tests result in an error. When 7x7 leveling was originally released, you'd get an error and the printer would go through the Z recalibration routine every time. The culprit turned out to include vibrations occurring at specific frequencies. Prusa introduced that "wait and retry" behavior shortly thereafter. 

Yours is odd in the consistency of repeating while moving left. Contact support via online chat when logged into the online store and send them that video.

RE: Strange hops on bed leveling, just started recently

@bobstro

Thanks - strange it started happening recently as well.  Every once in a while before it would do that double hop on a random point but never bothered me before.  Only recently has it started doing every time it moves left.

Gotta wait for this 24h print to finish then i'm going to turn that z nut in the right direction and recalibrate z and see if it goes away.  If not, i'll reach out to official chat.

Thanks for your insight 🙂

RE: Strange hops on bed leveling, just started recently

Just make sure you run the latest firmware, because that'll be support's first question 😉

RE: Strange hops on bed leveling, just started recently

Posted by: @geblah187

@bobstro

Thanks - strange it started happening recently as well.  Every once in a while before it would do that double hop on a random point but never bothered me before.  Only recently has it started doing every time it moves left.

Gotta wait for this 24h print to finish then i'm going to turn that z nut in the right direction and recalibrate z and see if it goes away.  If not, i'll reach out to official chat.

Thanks for your insight 🙂

Reversing the nut won't make it go away. It might affect the detected end of Y travel. Nothing to worry about if it calibrates.

The hops during bed calibration are absolutely normal. If calibration gets a reading it does not like, it retries.

As long as it finishes - you are fine. Mine has the occasional hop also.

RE: Strange hops on bed leveling, just started recently

Check out Joe's advice at 3'30''. One nut turned wrong will kill the setup.

RE: Strange hops on bed leveling, just started recently

Very good video for all new users.

RE: Strange hops on bed leveling, just started recently

@just3d

Turned the z nut the correct orientation, recalibrated z and the strange left hops went away. Good eyes and thanks for the tip 🙂