Here is the latest and most likely final fan bracket for the M2 Im going to produce. Complete re-design from the first two, added curved mounts for no obstruction of air flow and instead of mounting with one extruder bolt took advantage of the 2 holes on the bottom of the extruder. Offset the 50mm fan as everyone requested further to the right. Found it easiest to bolt on the 50mm fan to the bracket first then add the two 3mm standard nuts into the slots provided on the extruder hot end. Attached the bracket with two M3x16mm bolts being careful the bolts went into the nuts straight. Mounted the extruder hot end with the now fan bracket and 50mm fan to the extruder motor. Plugged back the wiring and then attached the 40mm fan. No jiggle or vibration as the holes are 3mm so nice and tight, will most likely need to screw the bolt all the way but this was intended. ADDED: For those who use the the right 2 stop holes and get really close to the frame I added m2fanbracketv3right Enjoy