Poor adhesion, bed leveling?  

RE: Poor adhesion, bed leveling?

Are you running current firmware? If you haven't already, enable 7x7 mesh bed leveling. It provides far more accurate results than the old 3x3 procedure.

RE: Poor adhesion, bed leveling?

First i would do the following.

1. As recommended change to a 7x7 instead of 3x3 for the mesh bed leveling.

2. If you are using octopi/octoprint there is a prusa leveling guide (it's more geared towards the nyloc mod, but can give you an idea of how out of level the bed is.)

3. Consider implementing the nyloc mod (basically replace most of the spacers with washers and m3 nylock nuts, i did it recently and gives you a lot more control on the levelness of your bed. Before i installed the mod my bed level variance was 1 and now it's around 0.06.

4. Verify the pinda is still the correct distance, it should be about the thickness of a zip tie (around 1mm) between the probe and the heated bed with the nozzle just barely touching the bed.

It might also be worth while to run through the xyz calibration test to make sure everything is still square and nothing has worked it's way loose. IN my case my z offset is around -0.750. Also this is using the smooth steel sheet as i don't have the powder coated one.

RE: Poor adhesion, bed leveling?

I have used the 7x7 and it didn't really seem to give me better results (or at least they were not better to a degree that I noticed a difference).

I do not use OctoPrint

I will certainly look into the Nyloc mod, I just wonder why the bed is so unlevel _now_ when it didn't used to be.

I have verified the pinda many times, but its difficult because the zip tie would be a tight fit on the left side and not even touching on the right side (and a less severe, but still quite noticeable front to back)

I also do the xyz calibration fairly often, I get regular clogged nozzles, a separate issue; but it means I have to disassemble the hot end often and I always do a full xyz calibration, pinda height adjustment, and mesh leveling calculations each time.

Is there a way (without Octoprint) to see exactly how level the bed is?

RE: Poor adhesion, bed leveling?

I think things like switching from 3x3 to 7x7 leveling, as well as many other minor tweaks, do not do much individually, but cumulatively they give more consistent and better prints.

If you think your machine is 'dimensionally challenged', you might try a technique discussed a while back where a known-accurate straightedge is used to carefully measure, and adjust if needed, the overall physical flatness of the print bed.

RE: Poor adhesion, bed leveling?

@jsw 7x7 in my view the way to go.  3x3 has too large of gaps in my opinion.  

RE: Poor adhesion, bed leveling?

Posted by: @cwbullet

@jsw 7x7 in my view the way to go.  3x3 has too large of gaps in my opinion.  

That's what I use (7x7), and if anything it helps.  Less than a minute of time is minor compared to the total print time of most prints.  However, I don't think that it is a magic bullet, particularly when other more significant factors exist.

RE: Poor adhesion, bed leveling?

@jsw

I could have been more clear.  I was trying to agree with you.  

RE: Poor adhesion, bed leveling?

I will definitely try these, the Nyloc mod, with the 7x7 and see if I can get back to having my MK3s being reliable.  Any idea why (or how) a bed could start to go quite a bit out of level?