Duet 6HC DIN mount with 25mm fans and ducting

Print in ABS or ASA, ducting is printed standing up, with supports to hold up the FC mounted part.   Be careful when sliding it on so you don't knock any surface mount components off.  Specifically the small capacitors near the stepper plugs.  

**Note: Duet's recommendation is to cool the back side of the board more than the front side if possible.  Unfortunately that didn't fit my mounting needs so this mount is a compromise.  It does still have airflow/ducting over the back side as well, but definitely favors the front.   My rationale is that any chip that's hot to the touch can benefit from cooling.  Since the driver chips are warm to hot while printing, the assumption is made that cooling them will benefit the board.   

Added a version with a mount for a 30mm fan over the MCU.  This is untested, but should work just fine.  I plan on using it with a 5v fan from the nearby 5V dedicated VFD/Laser/Servo header so the fan continues to run once the 24v PSU is switched off.