Everything was working great, until....
Finished build on Saturday, and with a little fine tuning printed logo, whistle and tree frog. Perfect every time. Then I noticed a nut was lying under the printer... I know, I should have stopped, but I didn't.
Turns out the nut was the bottom nut for the PINDA. Next time it goes to calibrate, I see the bed bending, and soon I have 9 little dents. I stopped it as soon as I realized what had happened and put the nut back on the PINDA, putting it as close as possible to the same (correct) position.
Since then I keep having trouble printing, with the PLA lines coming loose from the bed. The V2 Calibration almost prints perfectly, except it drags the last line off the bed to the stopped nozzle. When I print anything else, lines come off and I end up with a mess around the nozzle.
I've cleaned both the nozzle and bed and recalibrated - repeatedly, tried doing z-adjustments (getting just the right "squish"), but the PLA just won't stick. I've even used the glue stick without success. I'm using the standard 210/55, with a z-offset of -.250 (although I've tried a bunch of variations, from 0 to -.500.) I've also tried raising the bed temperature to 60 and a little higher.
Is it possible that the nozzle is damaged? Did flexing the bed cause a permanent problem? I don't want to remove and replace the PEI yet as my life experience suggests that I'll be compounding a problem.
TIA.
Re: Everything was working great, until....
Hi,
if the nozzle were damaged, you would had extrusion issues, which is not the case.
The incident you had should not afect adhesion, mostly only changed the correct Z-offset and maybe made some local damage on PEI sheet, which can fade away a bit after some prints.
The thing that could explain is the procedure you use to clean the bed: What do you use to clean the bed ?
I'm like Jon Snow, I know nothing.
Re: Everything was working great, until....
After conversation with Jan (thanks!) he diagnosed the problem as me not squishing the first layer enough (in order words, adjust z down to at least -0.600.) I had not adjusted this far down as the squish that was happening on the layer printed at the beginning of the print (he called it " the meandre") is NOT representative of the actual print, as it has an increased flow rate in order to stabilize the flow.
Eventually I settled on -0.750 and it seems to be printing much better. All of this makes sense as the PINDA is no longer in the exact position it was previously, and adjusting a fraction of a millimeter would account for the difference.
I'm just happy that I didn't start replacing the PEI layer. Once I read about the process of doing that, I wasn't looking forward to it!