Àutomatic bed leveling
Hi,
I'm about to purchase my first printer after a couple of years reading about them and watching countless YouTube videos. I have decided on the Prusa mini for my first machine. Im not new to CNC though, I am a CNC grinding machine programmer and operator by trade. I make carbide cutting tools. Anyway , that's just a little about me. My question is how does automatic bed leveling work. Is it a mechanical adjustment of the bed is off, or an adjustment in the code?
RE: Àutomatic bed leveling
There is an inductive proximity sensor mounted to the extruder. The firmware dips the inductor until it trips. It does this over a 3x3 or 7x7 grid. It then interpolates the surface within the grid.
The interpolation isn't perfect, the devs weren't experienced in proper use of matrix interpolation so the boundary conditions are rough (asymptotic behavior confuses them).
But over all, the method and interpolation adjusts for most surface deformation and creates a three dimensional mesh within 25 to 50 microns of what is actually there. As the extruder moves in x and y, the firmware adjusts extruder z by the mesh interpolation. So the resulting layer 1 is produced reasonably close to the desired 0.20 mm thickness over the entire bed. As the print height changes, the amount of adjustment decreases to zero, I think that's somewhere around 5 mm off the bed.
ps: and the process is automatic and performed before every print; started with a G80 command in the gcode produced in Prusa Slicer.
RE: Àutomatic bed leveling
Tim,
Thanks for the informative reply. I figured it was as you explained.