Got a brand new P1P a couple weeks ago. Was working great until suddenly prints would stop sticking to the bed. Discovered the problem was that the bed was not levelled properly and needed to be manully trammed. Ran the tramming script from the wiki and got it properly levelled. Then I ran the calibration procedure and rebooted the printer. I checked the bed level, and it was off again. Thought maybe the table it’s on isn’t stable enough. So I set the printer on the floor, re-trammed the bed, ran calibration, and again, the bed level was thrown off by the calibration procedure.
I’m at a loss here.
(And yes, I cleared the nozzle of any filament. And yes, I tried printing a test print without calibrating and it didn’t work.)
Looks like you’ll have to put in a ticket.
If the heatbed knobs become loose after you have performed the bed tramming procedure, you can try to tighten them a bit more.
One or two extra turns before starting the bed tramming can help solve this problem.
Spring tension is what keeps vibration from loosening the knobs and changing the bed level. It is important that there is always some tension and that is why the wiki shows the correct starting position - knobs equally flush with the end of the screws. A turn or so tighter will still work as long as none of the knobs become fully tight or loose during the procedure.
Narrow knobs and spring tension can make it difficult to turn the knob for fine adjustments. One of the many “wrenches” can improve grip and leverage to make very precise changes easy.
I’d like to emphasize what is probably obvious - tightening the knobs after tramming changes the bed level, so the tramming procedure should be repeated.
But wouldn’t I run the risk of the bed becoming so tight that it blocks the filament from coming out? The nozzle is already just touching the build plate.
Possibly tramming isn’t your issue? My X1 and A1 have 2k and 1k hours and I have done a tramming once for experimental purposes but consider it almost frivolous. There is no way to “map” in standard form (standard firmware) so you’re really visually guessing a gap at 3 points. My previous printers had klipper and I must admit it can lead to obsessive compulsive behaviour, I ended up fixing my bed solid and used bed levelling that seemed to cope with no side effects.
No. All the tramming does is make the plate as parallel as possible to the x-y toolhead plane. During automatic bed levelling the nozzle actually touches the plate in multiple locations and three force sensors under the plate collect data to detect any remaining variations in bed height. That data is then used to raise and lower the bed, keeping the nozzle at a constant distance from the plate as it moves around.
The bed basically “floats” on top of stiff springs, kept from moving side to side by three bolts. The knobs are not tightened so much that the bed cannot move up and down - you should be able to see a little movement if you squeeze a knob and plate together. Think of the knobs as adjusters rather than fasteners holding things tightly together.
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Judging when the nozzle is “just touching” can lead to second-guessing yourself a lot. Same for using feeler gauges and trying to judge equal drag. I’ve had better luck with my X1C by having a strong light behind the nozzle, putting my eye at the edge of the bed and watching for light shining through the nozzle-bed gap to disappear. The difference between light shining through a tiny gap and darkness is abrupt and easily detected.
Proper tramming can greatly reduce the amount of compensation required from the ABL. Constant z-height adjustments cannot be a good thing.