BLTouch does not compensate for differences in bed level

Question

Printer: Ender 3 Bed: Creality Glass ABL: BLTouch Everything else: Stock

Few weeks ago I had a meltdown during a failed ABS print. My hotend was completely wrapped in plastic and trying to remove said plastic I snagged the termistor. Anyway I had to replace the nozzle, hotend and thermistor. Everything on here. I went ahead and measured the Nozzle BLTouch needle offsets and re-flashed my Ender 3 with TH3D Firmware and configured BLTouch. After which I adjusted the Z offset again.

All good here. BLTouch appears to work, well at least it appears so.

I started printing and I see that my bed always hangs lower on the right side and BLTouch does not compensate for this difference.

Manual leveling (with a heated bed, also tried without)

1. Auto home
2. Move Z axis from 5 to 0
3. Move the head to each corner of the bed
4. Adjust the corner hight using the paper method (repeat 2x for each corner)
5. Auto home
6. Move Z axis from 5 to 0
7. Go to Z offset, and move it until it tugs on the paper.
8. Save and Auto home

But this did not solve the issue. When I move the head to Z0 (with the offset) in the centre it's perfect. Moving it to left gets close to the board, right goes way away from the board.

Belts & screws
Went and tightened all the belts and all the screws.

X Axis alignment
I set the Z axis to the max 250. And measure the distance from top of the X axis to top of the frame. There is no difference in the left, right or centre of x axis to the top of the printer. Same for distance from bottom part of the frame.

I cleaned the belts and the wheels with a soft brush. Not sure what else to do. I'm giving up on Creality/Ender :(

Answer 1

The issue was BLTouch i'm not sure what use is this thing if it cannot compensate for differences in bed or frame.

I'm not sure why but the probing seems to be bad. I tried everything clean TH3D install and config, pitch perfect alignment of everything frame, bed, mounts everything. Perfectly calibrated Z offset at the centre of bed. I triple checked the belts. Checked if X axis was off or if any screw was lose, checked wheels to make sure everything was snugg.

Anyhow in the end the issue was with bad BLTouch probing not sure why. I gave up and went and disconneced BLTouch did manual bed leveling with the paper method. Press print and I got a perfect print. Like literally perfect. Even extrusion everywhere.

BLTouch seems to have probed the distance at the centre of bed, I set the offset for it. Than when it went and probed other corners before the print it seems to have read the values wrong.