I recently made the switch from the marlin-based stock firmware on my anycubic kobra 2, to klipper. I didn't have issues with bed levelling or first layer on the stock firmware, but I'm having significant issues running klipper. The bed is uneven, the probed mesh shows a deviation of 0.197mm, it was the same when running stock FW+octoprint.
But it seemed to be correcting just fine for this on the stock FW. I got a consistent decent first layer across the entire bed.
With klipper, it's absolutely impossible to get it to correct for this unevenness. Half the bed will get perfect first layer, but then the second half is either way too squished or hardly connecting to the bed. And it's causing further issues as it's also hitting the print when moving, despite having Z-hop of 0.3mm for travel moves.
Is the problem along the X Axis? Maybe you have X Axis Twist. Measure z offset on opposite ends of the bed along X. If they are different you need to enable X Axis Twist Compensation.
I literally went through this the other day on my franken-ender 3v2. Re-leveling the bed, even tried axis twist compensation.
I’ve been using Klipper on this thing for a few years and overall it’s been good but finally decided to figure out why I couldn’t get even extrusion across the entire bed even with my klackender probe.
After days and days of trying to adjust, tighten, loosen screws, redo hot end to be sure it was properly mounted, even axis twist compensation (which it definitely was) I just went back and just took it apart and redid the frame. Making sure it was square, nothing was overtigtened, that the vwheels weren’t binding, tightened just past there being any “slop”, etc.
Then I removed the compensation hoping that the issue was mechanical and what do you know, it worked.
I had way over tightened some things obviously and so just going back to the foundation fixed the issue.
It’s working great now and klipper properly works with the slight warped bed of my Ender.
Yeah i actually ended upndoing something similar. Took the hotend and entire bed assembly apart, cleaned and lubed the rails and reassembled. It's been working fine since.