This is day one of replacing the horrible Makerbot (clone) firmware with a RAMPS board running Marlin.
I wish Marlin would run on the Mightyboard, it's a very nice piece of hardware. Shame about the horrible, 2009 feeling firmware. If it were running Arduino I might take a stab at it but I don't think it is. It is an ATMega chip and I suppose I could probably cram an Arduino bootloader on it. Might be worth a play once I get the RAMPS board going. Right now I don't want to potentially wind up with a completely bricked printer. Even if I get a bootloader running I'd have a lot of fooling around in pins.h to get all the I/O running on this thing. It is an open design though so it's not reverse engineering, just time.
Anyway, I was just poking around today, looking for pitfalls I'm going to encounter. I really don't want to cut any wires and make this irreversible. First challenge was that the stepper motor connectors are using large connectors about the size of molex connectors. I found that 14 gauge solid copper wire, removed from Romex cable, goes in just fine so I can make an adapter. Also the last two pins on the endstops can be wedged in, though since the X and Y are max stops and the Z is a min stop, I may not be able to fit the Z in very well.
Today I just got the firmware compiling, the LCD is working, I hooked up to a bench power supply and just attached the X motor and endstop and made it home that axis. Worked fine first time.
Next up is to pull the print head and install thermistors instead of thermocouples, since the RAMPS electronics does not have thermocouple amplifiers like the Mightyboard does, and I don't really want to pay $30 for a pair of amplifier boards for no good reason - there's nothing wrong with thermistors.