First layer calibration problems  

RE: First layer calibration problems

My first guess is your Z-Offset is way too low.  You need to reset it to zero then start fresh.

RE: First layer calibration problems

check that is sees filament sensor seeif it thinks it has filament. did you upgrade the firmware?

RE: First layer calibration problems

Go into Support and then Sensors and see what the IR sensor is reading. I bet it's 0 so the printer is sitting there thinking there is no filament. 

My advice would be to disconnect the MMU and get the printer dialed back in as a plain MK3S. Once that is all good, then add the MMU to the mix. 

IF I'm correct about the IR sensor there are 3 options I can think of. First the sensor is bad (or got plugged in backwards and is now bad). Second is that I've read reports of the arm on the door needing some triming to work better. Lastly, loosen the bolts on the chimney, slide it as far to the left as possible, and retighten the bolts. 

Start backwards and without the MMU attached it should be quick to test the IR sensor. 

RE: First layer calibration problems

If it is any consolation, I am having the exact same problem.  Hopefully one of us will figure it out.

Todd

RE: First layer calibration problems

+1

but slightly different.

after running through the assistant and it comes to first layer calibration the MMU tries to load from port 5 instead of 1 (if I enter a filament in 5 it does not work either ). Then after a MMU reset it tries to load from one and calibration starts. But there is no way to get the bed calibrated (it was working great before MMU)

If I do a test print it looks creepy like that:

RE: First layer calibration problems

Checked the IR sensor. It's at zero, can't get it to go to 1. Tried the IR sensor that was in there before the MMU2 upgrade. Still 0. Checked to see if it was getting 5v and it is.

now what?

RE: First layer calibration problems

I also took the IR sensor out of the chimney and just put some filament in it. Still 0. I tried this on both sensors.

RE: First layer calibration problems

I turned the IR sensor off via the setting control. Still prints blobs.

Fixed it

Fixed it. The IR sensor connector on the Einsy was backward. Red wire right, white wire left.

RE: First layer calibration problems

I am having a weird problem as @oliver-r13 but mine is in the lower middle and ideas?  i have an upgraded MK2.5

RE: First layer calibration problems

Are you using 7x7 Mesh Bed Levelling?

Are you using the 'Life Adjust Z, My Way'  first layer calibration, or similar in preference to  the Prusa option?

regards Joan

RE: First layer calibration problems

I am just using the Prusa first layer program to adjust the Z-Axis. If i move the z axis to make  changes to the low area then the rest tend to be to high. Do you think my bed is warped?

RE: First layer calibration problems

@james-p8

perhaps if you enter into dialogue with people trying to help you, they may be able to help you more. 

Have you ensured that there is absolutely nothing stuck between the steel build plate and the heatbed (this includes (but is not limited to)damaged PEI, failed print material, waste filament and any surface preparation...)

the Original Prusa is supplied as standard with 3x3 Mesh bed levelling (the printer senses 9 points on the build plate)

You can set the printer to use 7x7 Mesh bed Levelling, (the printer senses 49 points on the build plate) (this is under the settings option on the LCD Menu)

using 7x7 Mesh bed levelling can resolve a lot of issues.  

I asked but you didn't answer. so I have no idea which you are using. 

you did say that you are using the Prusa first layer calibration tool. this is not the easiest tool to obtain a good Live Z setting. 

I use https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/

try these items and then see what your large area test looks like? 

regards joan