Calibration Failed
I am a MK2 user and I just assembled the MK3 with no issues whatsoever, and everything seems fine (movement of all axis, etc.). The firmware version is 3.4.1-1356.
After the pre-flight check I started with the Wizard and all systems passed in the self-test (fans, hot-end, bed, range of motion, etc). But during the next step, Calibrating Home, the PINDA lowers very close to the circle mark however when it starts scanning it immediately moves away - forward and to the left. So far forward that the print bed hits against the back stop when scanning the Y axis because the bed is going as far back as possible. It does not indicate an error and continues on to Calibration.
Starting Calibration and before raising to the top of the Z axis it does an "Auto Home" and again it goes one more time in the wrong area, to the left and front of the circle mark (and I can hear the bed hit the back stop). It's as if the PINDA probe thinks the sensor is at the tip of the front left corner. It leaves the PINDA probe about 5 mm left of the circle and 5 mm in front of the circle. It then raises the Z-axis against the stops to level it as it should.
The next step, Searching bed calibration point 1 of 4 fails immediately. It lowers and leaves the PINDA about 5 mm to the left and 5 mm in front of the circle mark. This is where I'm stuck.
I've made slight adjustments to the height of the PINDA probe with no effect, I've also started the Wizard with the magnetic plate on (removing it when told to do so) with no effect.
So after many, many hours of assembly I'm looking at a brand new MK3 and can't do anything with it! Your help and suggestions appreciated.
Re: Calibration Failed
ISTR faintly (either from this forum or the comments on the online assembly manual) that this could be a symptom of a faulty PINDA.
My suggestion for a checklist would be:
- PINDA offset (0.5...1 mm higher than the nozzle)
- PINDA cabling (I know, it's a PITA, but at least unplug and reseat the connector on the EINSY board and check for its correct position and orientation vs. the online version of the setup manual)
- contact support
Re: Calibration Failed
Problem solved thanks to PRUSA support. I thought I was extremely careful during each step of assembly however I assembled the hotend incorrectly. It seems like it would/should be impossible to mount it incorrectly as the housing wraps around it and holds it but the hotend ended up about 3/4" lower than it should be, even though it was firmly mounted in the housing. (A telltale sign is the PINDA has to accordingly be mounted very low also to meet the required tie wrap spacing, with almost all of the PINDA threads exposed and only a few to clamp onto).
Luckily it was easy to fix - remove the fans, take off the extruder cover and seat the hotend correctly in the housing. They told me this is a fairly common assembly error.
Thanks to PRUSA support for knowing almost immediately what the problem was (confirmed by me sending them a pic of the hotend) and guidance on how to fix it. I was nervous I had a bad PINDA but it turns out to be user error.
Re: Calibration Failed
TL;DR: Use a paper under the PINDA height adjust process when moving the extruder (Step 9, Preflight). Rotate the threaded rods down until it contacts the paper and prevents it from sliding. Then raise it just a little bit so it slides without much/any resistance. Repeat for the right side. Move to the center and use a paper on the bed when also using the PINDA sensor adjustment with the zip tie.
Also consider the tension on the belts, try for 250 (lower number -> tighter). Getting belt tension down to 260 or 250 would be ideal, just dont break something. Support->Belt status. The numbers should be lower and ideally 250 for each. A higher value = looser belts. I didnt change the belt tension (mine were too loose at 270 and 310). Good steps that describe that are here ( https://manual.prusa3d.com/Guide/4.+Z-a ... g=en#s9981 and Y axis belt https://manual.prusa3d.com/Guide/2.+Y-a ... g=en#s8225). Reportedly the Support->Belt status values update after passing the self test. [/b]
See the rest of the discussion and the full thread at: https://shop.prusa3d.com/forum/others-archive--f66/self-test-error-x-axis-length-t13327-s10.html