I have a prusa i3 that I built from a BOM. Using a standard aluminum frame I am getting some clearance issues.
Clearance issue #1 X axis motor is so close to my ramps board that it was actually shorting it out.
Clearance issue #2 if you are using motors with couplers instead of motors with built in leadscrews, the Z axis barely has enough clearance to zero out the nozzle on the bed.
otherwise I love this set. Just have to jerry rig something until I can get a more permanent solution to my clearance issues.