Auto bed leveling - not level

Here is my continued adventure of "nothing sticks to the print bed"...

A year or so ago I bought a Prusa i3 kit (aluminum frame, heated build platform - pretty much the standard). It gave me accurate prints and everything with one simple issue - I couldn't get the prints to actually stick to the bed for more than a few layers (classic hairspray + glass method - with the same hairspray working fine on another printer). I solved the problem by using ABS juice for printing. Because that thing can pretty much work with anything. Problem with that is that you sacrifice accuracy and nice finish with that. Fast forward to today...

I recently bought an inductive sensor and installed it on my printer. I replaced the Z endstop with it and I stuck some conductive tape on the four corners of the bed. I enabled autoleveling in marlin (version 1.0.2) and configured it correctly. I also manually calibrated the bed as much as possible - though I could never get the thing calibrated properly for some reason. At least one corner was always a bit off. That's one of the reasons why I actually went for the autoleveling probe.

And now for the issue. I do the autoleveling and everything looks nice. The problem can be seen when printing the first layer of a larger object. Fillament will be squashed and stuck nicely on the right side of the print bed while it will be too thin and unsticking on the left side. Autoleveling is apparently working - I can see the Z axis moving. I also tried changing the probing positions a bit - no luck. I also tried manually raising the left side of the bed a bit - didn't help. So autoleveling is apparently working and detecting the corners but the calculations seem to be wrong for some reason. And I have no idea what to do anymore.

Sounds as if your bed is warped. I got around this by auto levelling on Glass. I basically stuck some copper tape at the probe points on the glass and now have no issues at all. You can use anything thin and metal to do this, Aluminium foil, Copper tape, razor blades etc... Failing that you can always get a new Aluminium tooling plate which is guaranteed to be flat.

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Ax
Sounds as if your bed is warped. I got around this by auto levelling on Glass. I basically stuck some copper tape at the probe points on the glass and now have no issues at all. You can use anything thin and metal to do this, Aluminium foil, Copper tape, razor blades etc... Failing that you can always get a new Aluminium tooling plate which is guaranteed to be flat.

Wait... where else would I do auto leveling? I have a heated build plate and a glass plate on top of that. And I have metalic tape stuck to the top of the glass.