Sorry if this has been answered already, I wasn’t having any luck with searches.
We have a TAZ 6, completely stock with a single extruder head. It has been working great for the past few years but recently problems with the prints have been showing up. I’m going to start with the auto-leveling issue because that will likely solve many other problems…
When a print begins and the head goes around touching the metal pads on the corners, the bed is physically pushed down on three of the four, with the worst being pushed down around 2-3mm. I’m not sure exactly how the sensor works but making the assumption that there is some voltage passed between the metal surfaces I tried wiping down the nozzle while it was hot to make sure there was no excess filament. While I have seen the ABL process fail due to a dirty head (touching the first pad then going back and wiping the nozzle again), it is NOT doing that now. Since the nozzle pushes the bed down quite a bit I’m pretty sure something in the bed leveling process is failing – how would I troubleshoot this?
My own experience is with manually leveled beds on other printers, so I tried a 5-point leveling test print to see where I’m at. The results made it clear the nozzle is too close to the bed, even scraping up the filament on the corner that gets pushed down the worst. I attempted to adjust the Z-offset with M851. The original value was at 1.20, and it looked a little better as I reduced the value, but by 0.90 the filament wouldn’t stick to the bed (not surprising). Even at 1.00 the surface of the test print was very rough as the nozzle offset previous strands of filament, but results were a bit better. Obviously since I’m still not getting a smooth top surface my attempts to change the Z offset did not help the problem, so I’ll revert the value back to 1.20 and try correcting the auto-leveling process instead.
Any help is appreciated.