Now... First layer problems. For me.  

Re: Now... First layer problems. For me.

I have been on holiday for a week. I come back and now I am getting first layer problems with my Prusa I3 MK2 running 3.08 Firmware.
Are you sure nobody had access to the printer? Nobody played with it during your holiday? Nobody cleaned the surface of the bed?
Where was the printer located during holiday? Maybe it was under direct sunlight and PEI sheet degraded a bit under UV radiation although I don't know if it's possible.

Re: Now... First layer problems. For me.

I am having same issue using FW 3.0.8. My printer does not store calibration settings. I run XYZ calibration successfully. Then I print some staff and turn off printer. After I power on printer it say "printer not calibrated"
After XYZ Calibration I adjust Z height to have proper printing. Printed object looks ok. However when I try to print next object the Z is again de-calibrated and I have to increase the Z (it looks like I need to always add 2x previous value). If I reset printer or power off/on then I need to XYZ Calibrate again.
So I end up in endless loop of doing XYZ Calibrations and adjusting the Z. It driving me nuts already. In CZ forum I saw recommendation to downgrade to FW 3.0.7. Because I did buy KIT helpdesk does not want to speak to me at all.
Going to downgrade FW to see if it helps.

Re: Now... First layer problems. For me.

MilanNXT, The warnings only clear upon running the latest version of V2Calibration downloaded from Prusa's website. It has a gcode snippet that sets the first-run calibration parameter. Older versions of this file don't work.

David, is there any possibility your filament absorbed too much moisture? Might it have been moved? Are you sure you have the latest V2Calibration?

Re: Now... First layer problems. For me.

Curtis, thank you for the hint. Seems it resolved the issue with storing calibration.
I was curious so look into file but I haven't found any special codes there apart of two G88, G87 drilling commands. Perhaps there is some code in FW to recognize this. I do not find this as good idea.
But anyway. What if I have ABS filament loaded. This calibration gcode file would not work as its intended for PLA.
So they should create few version for different materials.

Re: Now... First layer problems. For me.

Just edit the file and change temperatures to your needs.

Re: Now... First layer problems. For me.

If your probe is set correctly, maybe your heatbed has warped. When I got my Mk2, my heatbed was flat. After a few weeks of use, tweaking, cleaning, scraping, pressing (whatever it was), I noticed a slight warp. The surface was very slightly concave. My adhesion was usually terrible, and V2cal looked really inconsistent, sometimes squished nice and flat, and sometimes round and wiggly. The edge of a nice metal ruler showed a gap in the middle. I just loosened the center screws slightly. If you do this, be careful not to let them fall out, you'll lose your Y-belt holder. Hope that helps.

Re: Now... First layer problems. For me.

Thanks for replies. My printers are in a room with a door alarm and the curtains closed. No one interfered with them 🙂

My printbed looks level and is aligned well. Calibration does complete and say all axis are perpendicular. I have tried printing PLA and NGEN with same problems with adhesion and poor layering.

I use the calibrateV2 gcode. I am at a loss for now.

Re: Now... First layer problems. For me.

Basically having same experience. Adhesion on MK2 is much more complicated then on my previous I3. But I must admit, when you resolve adhesion problem then print outs from MK2 are much better then from I3.
My experience with adhesion shows that you really need to make sure your bed is absolutely clean and degreased (make sure you are not using cleaners with some anti static features). Then you need to really play with tuning Z axis. Don't be afraid tu pull it, while printing V2Calibration watch the distance between your nozzle and bed and make sure nozzle is as close as possible. Also before on I3 I never used things like Brim/Raft but with MK2 is safer to turn it on.

Re: Now... First layer problems. For me.

Curtis, thank you for the hint. Seems it resolved the issue with storing calibration.
I was curious so look into file but I haven't found any special codes there apart of two G88, G87 drilling commands. Perhaps there is some code in FW to recognize this. I do not find this as good idea.
But anyway. What if I have ABS filament loaded. This calibration gcode file would not work as its intended for PLA.
So they should create few version for different materials.

I mis-spoke. It appears that the calibration warning is triggered upon startup anytime Live Z = 0. And this value is reset to zero when you flash or do either Z or XYZ calibration. And you're right, V2Calibration has to have the temp changed if you're going to do it with ABS.

Merv, is your Live Z != 0?

The G87 and G88 codes have something to do with setting baby steps increments, which enables Live Z adjustments.
/**
* G87: Enable babystep correction after home
*/
case 87:
eeprom_write_byte((unsigned char*)EEPROM_BABYSTEP_Z_SET, 0x01);
break;

case 88:
break;

Re: Now... First layer problems. For me.

Curtis, thank you for the hint. Seems it resolved the issue with storing calibration.
I was curious so look into file but I haven't found any special codes there apart of two G88, G87 drilling commands. Perhaps there is some code in FW to recognize this. I do not find this as good idea.
But anyway. What if I have ABS filament loaded. This calibration gcode file would not work as its intended for PLA.
So they should create few version for different materials.

I mis-spoke. It appears that the calibration warning is triggered upon startup anytime Live Z = 0. And this value is reset to zero when you flash or do either Z or XYZ calibration. And you're right, V2Calibration has to have the temp changed if you're going to do it with ABS.

The G87 and G88 codes have something to do with setting baby steps increments, which enables Live Z adjustments.
/**
* G87: Enable babystep correction after home
*/
case 87:
eeprom_write_byte((unsigned char*)EEPROM_BABYSTEP_Z_SET, 0x01);
break;

case 88:
break;

Re: Now... First layer problems. For me.

@curtis.b Yes my Z live is zero! However I adjust it, it makes no difference. I suspect a hotend problem and extrusion. The filament was sitting cold in the hotend for a week whilst I was on holiday in Yorkshire. I may have a partial hotend block.

Re: Now... First layer problems. For me.

The printer was left cold for a week. My errors in printing were after switch on. I decided to re-flash 3.08 fw and start again. The calibration now complained of severe skew. I took a look at the geometry it still looks good. Apparently a 1mm error can throw the printer off. According to pjr. It resolved apparently, but first layer prints would still not adhere.
I tried a raft, a succesfull print. There is something wrong with first layer extrusion and adhesion?

So I am passing this printer onto experts greater than me. A local maker group, as a donation. I always intended to donate this printer to a Maker Group. The auto levelling software needs further work. (My PEI surface was cleaned with 99% IPA)

3D printers are for the so called experts. The two printers that have never given me any problems are manually levelled. My Ultimaker 2+ and Hobbyking Fabrikator Large, once set they work! I added Printbite to the glass on both 3D printers. I have no adhesion issues. When the print cools down, with PLA, you can pick it up from off the bed without a scraper.

My Hoobyking Fabrikator Large is printing well with ColorFabb 1.75mm Grey Ngen.

Re: Now... First layer problems. For me.

Make sure bed level correction is reset before attempting calibration. I got severe skew before setting that back to 0 where the results were slight skew.

Re: Now... First layer problems. For me.

Thanks for reply prusayo. Yes I reset XYZ before calibration. I found some geometry issues as pointed out kindly by Peter pjr. That solved my problem. I live and learn. Thanks to you all that replied. I moved the printer to clear some space, I must have upset geometry by a 1mm or 2. I was suprised it upset the auto-levelling software so much.

Re: Now... First layer problems. For me.

Make sure bed level correction is reset before attempting calibration. I got severe skew before setting that back to 0 where the results were slight skew.
Oh, now that just sucks. I had to redo all of my calibrations because I assumed that the bed level corrections would be reset upon doing the XYZ. Instead, it only exacerbates the problem!

Josef, Prusa et al, I'd suggest that bed level corrections are invalidated by an XYZ calibration and should be reset to zero before running the calibration, and perhaps a warning sent before the calibration is started.

Re: Now... First layer problems. For me.

curtis.b I totally agree with your comment above. And shown below.

Quoting curtis.b "Josef, Prusa et al, I'd suggest that bed level corrections are invalidated by an XYZ calibration and should be reset to zero before running the calibration, and perhaps a warning sent before the calibration is started."

Re: Now... First layer problems. For me.

curtis.b I totally agree with your comment above. And shown below.

Quoting curtis.b "Josef, Prusa et al, I'd suggest that bed level corrections are invalidated by an XYZ calibration and should be reset to zero before running the calibration, and perhaps a warning sent before the calibration is started."

I sent an email to their support address as they don't always read these forums. We'll see what happens.

Re: Now... First layer problems. For me. (solved)

Just to be clear. This issue is solved for me now. I am getting great adhesion after running latest V2calibration.gcode and adjusting Z level by approx 0.5 mm.

My frame moved when I moved the printer to clean up and make space, a nut had become loose. I tightend things up and started calibration again. After I reflashed with 3.08 < not needed!!! I am a happy bunny again 🙂 A bolt fell off too. For the life of me I cannot see where this M3 by 10 bolt is missing! The main thing is my Prusa MK2 is back in action again and giving brilliant prints.

Re: Now... First layer problems. For me. (solved)

... A bolt fell off too. For the life of me I cannot see where this M3 by 10 bolt is missing! The main thing is my Prusa MK2 is back in action again and giving brilliant prints.

Merv , check under the PSU.