MK3 / first layer calibration failure
Haven't been able to print for months and am at my wit's end why this is so. Hopefully someone can point me in the right direction.
Things I have checked:
I always download the latest firmware (3.6 from 1 March 2019) and have no problems flashing it onto my printer.
The filament is of good quality and I have used it regularly: it autoloads and unloads perfectly.
In any case, I have tried 3 different filaments from different brands, including the grey one provided by Prusa
The complete hotend is brand new and has just been provided free of charge, courtesy of Mr Prusa (thanks guys!).
The wizard up to the first layer calibration is fine (perfect assembly/ perpendicular etc..)
Z Calibration specifically done before the FLC is fine.
The print bed is clean
Things that do not work:
The issue happens when I try a simple first layer calibration (FLC) and 3 things happen:
- the filament does not come out at all (but there is no blockage since loading/unloading works well)
- when I change the Z height with the knob during the FLC , the print head does not go up or down
- the FLC circuit is shortened: the initial zigzag is cut short and the print head moves into a diagonal directly to the last part (short distance back and forth).
I have filmed this with my phone but cannot upload the mp4 film as an attachment.
Needless to say that when I try to print anything, the printer executes the gcode but no filament comes out.
I would be grateful for any help as I have previously tried all sorts of solutions offered on this forum: cold pull, change nozzle, flash firmware etc..
Re: MK3 / first layer calibration failure
If the nozzle is too low, no filament will come out. This is probably what you are seeing.
During Layer One Calibration, the movement in the Z-Axis is microscopic - you won't see it move up or down. Also, since the nozzle is probably dragging on the bed, the printer is stalling and will do weird things rather than move in a predictable manner.
Select First Layer Calibration from the LCD menus, and set the offset to 0 as quickly as you can, and work from there. At 0, you should see extrusion, but it may not be sticking to the bed. Then fine tune the value more negative to get a proper layer one fill.
Re: MK3 / first layer calibration failure
Thanks Tim, I'll definitely check this out and will post my results here.
Cheers
Re: MK3 / first layer calibration failure
Still not working.
I now suspect it might have to do with the einsy board or the pinda probe.
Why?
Because the hotend is new, the filament is ok and flows normally when loading, so there is nothing mechanically wrong.
That means that electronically something is wrong: either the pinda probe does not relay the message to the hotend saying it is ok to pour out filament or the einsy board is damaged.
I should mention that I have of course adapted the height of the pinda probe several times just to see if there was a different reaction, but unfortunately no flow...
Any suggestions?
Re: MK3 / first layer calibration failure
Attempt to run the First Layer Calibration. Let it finish.
Now that the printer is powered up and homed (has xyz 0,0,0 set), you can do some tests.
Preheat to the filament you have loaded. Attempt to extrude 1mm of filament (manually move E +1 mm): if nothing is coming out, raise Z by 1 mm, and try extruding again (move E another +1 mm - and don't move E backwards, always move positive). If nothing is coming out at Z=1.00mm, raise Z to +3.00 mm and try moving E +1 mm again.
Take a photo at each step in this process and post it.
Re: MK3 / first layer calibration failure
Hi Tim,
Followed your advice, did an empty FLC, and then did an unload/reload filament which worked fine, so the filament comes out again
No pictures, sorry!
Tried another FLC, but same problem again, no filament comes out...
What does that prove?
What do you think of my Pinda/Einsy board theory?
Cheers
Re: MK3 / first layer calibration failure
Did you try raising the extruder from 0.000 to 1.000 and do a manual extrude? Your reply wasn't clear you did. If you tried this, and no filament was extruded, did you see the extruder raise up in 1mm steps as you moved the Z axis?
Also - are you seeing the PURGE LINE near the home position?
If the printer is reporting 215c/60c, and you are not seeing a purge line, that almost proves the nozzle is too low for the First Layer Calibration. If raising the nozzle 1 mm or even 2 mm still doesn't result in flow, then your Z-cal value is way off, and a full factory reset is probably called for. Pretty easy to do now you have things aligned. Just takes some time.