I've been trying to get a Rostock based delta printer running, but am having problems with the firmware. I'm using an Arduino MEGA with a RAMPS 1.4 board. Right now the main problems seem to lie in homing and heating the hotend. The wires are connected to the hotend as I've been able to heat it using an external power supply.I have also tried the modified Marlin code that the Rostock has pointed to, and only been able to make the motors move individually with no real intelligent direction, mostly just gcodes and putty commands. I was told to use repetier, and I'm starting to use it now, but it's still not fixing these problems.