How does the auto calibration mechanism for delta printers work


I am currently building my first self designed delta printer (because the Chinese kits lack mechanical stability).

After setting up the firmware and some basic sizes (rods, z-height, ...), I tested the auto calibration method of Marlin. I was surprised, that this method came with slightly different horizontal distance values then I entered initially (~185 mm vs 190 mm).

Can someone explain what this method is actually doing, how it works in detail and how it calculates the horizontal distance, by just knowing the rod length? I have not found much more than it seems to be a "least square" method and tipping some points.


Posted 2018-09-24T14:03:49.703

Reputation: 654

Are you sure that the Marlin bed leveling is actually adopted to the special needs of deltas? Maybe it is just doing a Cartesian bed leveling,.. – Lars Pötter – 2018-09-25T20:01:00.250

Yes, it seems so. I thought there is a paper somewhere, but I haven't found it yet :/ – dgrat – 2018-09-27T08:14:22.053

No answers