I printed it at 2mm layer height and 40% infill on a .5mm nozzle, came out very strong and printed without defects. No support needed for all but perhaps the extruder body part, that may benefit from support to keep the clearance for the extruder groove clean, but either way you will probably need to clean this are up a bit, it's a tight fit either way. Clean out the support in the servo mount and all should be good. Use 4 - 4mm machine screws and hex nuts for mounting the body to the i3 Rework X carriage. 4 - 3mm socket cap or machine screws and hex nuts are used to hold the extruder bodies in place and allow for z calibration of the heads. 4 - 3mm socket cap or machine screws are used to hold the extruder top to the extruder body. 1 - 3mm socket cap or machine screw and hex nut to hold the fan mount on. Finally, whatever you need to mount the fan to the fan mount and shroud.