I have a Folger Tech Kossel 2020 Delta printer that has worked great for years but recently stopped heating the bed. Troubleshooting isolated the problem to either a Polyfuse or a bad FET on the RAMPS board. I ordered and installed what appeared to be a viable replacement board from Amazon (link).
I uploaded my usual Arduino firmware and was able to successfully test homing, heating the bed, and heating the extruder. I recalibrated the Z distance so the hotend goes to the correct location... then tried to print something.
However, when slicing and printing a 20mm calibration cube, the hotend moves to about 10mm off of the build plate and starts printing like it thinks the build plate is at a ~30 degree angle. All three tower motors are working, it's just that the printer appears to be behaving like it thinks its a square XYZ printer rather than a round Delta printer.
I then tried rehoming and manually sending G1 Z0 - and the hotend goes to the expected location in the center of the bed.
It seems like my new RAMPS board is either expecting slicer GCode of a different flavor than used to work fine with my failed Folger Tech RAMPS board, or perhaps that there is a setting somewhere in the Arduino firmware that isn't at the correct value to talk to the new RAMPS board. I've tried changing the motherboard type in Configuration.h but no joy.
Since this forum apparently wont let new users upload files, I put a copy of the firmware I am using on google Docs: https://drive.google.com/drive/folders/11T-26nT9PxZOMb8pNTon5iCKJDxtsYu9?usp=sharing
Thanks in advance for any help you can provide.