Not familiar with the MicroMake, but on my Rostock the carriages have screws for triggering the endstops, so using Minow's delta calibration guide, I can manually adjust each screw to calibrate the bed.
Alternatively, Escher3D has a web-enabled wizard for manually calibrating your build surface with his least-squares (?) routine used in the RepRapFirmware. I believe it should have instructions for sending commands to your printer via gcode.