(note! The stl for the "frame" (or cage) part has been updated to fix a reported problem with fitting at the top between the Ultralight mount's screws and the motor. With the revised "Frame.stl", no sanding should be needed now.) :)
(Another note! Sept 2018: I redesigned the "Duct and fan mount for..." parts from scratch. Some people were having trouble getting their slicers to accept the old versions and the files were pretty messy anyway. The new ones are a little easier to print and assemble, a little lighter, and no longer need the nozzle spacer, although I left that file here in case further tweaking is needed)
This set is to provide a cooler for use with the 713maker.com Titan Aero ULTRALIGHT Extruder mount, with either a Volcano or E3D V6 hot end, for the Folgertech FT-5 printer. It is designed to be used with a 25mm deep NEMA 17 motor (17HS10-0704S), but there is a spacer to alternately use it with a 20mm deep "pancake" motor. It provides a VERY rigid and lightweight cooling solution using a 50mm x 50mm x 15mm blower fan with a direct path from output to the duct outlets while pulling cool air from the side (instead of from close to the heated bed).
All parts print without supports or rafts (though a cooler or side fan would be needed to print cleanly).
Note that not all 50mm blowers are created equal! I don't know of any of the ball-bearing types that will work with the PWM speed control provided by the MKS board of the FT-5, so unless you want to experiment it might be best to steer clear of those. For other fans, the thing to look for is the current rating -- a 12V 0.06A rated fan will work ok, but its output is pretty wimpy. Look for a 12V 0.1A to 0.16A fan, those seem to move quite a bit more air (you may even need to turn the speed down to 50% or so in some prints, quite a lot of air gets pushed out by this cooler.).
Note, also shown are my "BLTouch Mount for Titan Aero" (https://www.thingiverse.com/thing:2543467) and "Titan adaptor for using 3mm ID reverse-Bowden tube" (https://www.thingiverse.com/thing:3113268)
Duct and fan mount for Volcano.stl: The duct and fan for use with Volcano hot end.
Duct and fan mount for std V6.stl: The duct and fan for use with a standard V6 (non-Volcano) hot end.
Frame.stl: A lightweight cage that goes around the motor and provides a mounting surface for the duct and fan
Back plate.stl: A plate that screws onto the back of the frame/cage and and to the back of the motor, providing better support for the frame.
Nozzle Spacer (optional).stl: a spacer to let you lower the fan duct 2mm closer to the print bed if desired. Most slicers will also let you adjust the thickness of this part if you want. Using the spacer will put more air on the part and less on the nozzle, but will reduce clearance of the duct from the bed (more likely to run into mirror mounting clips, for example).
Motor spacer (optional) for 20mm pancake: Lets you use a 20mm pancake motor instead of the 25mm pancake motor, for further weight reduction.
The screws to hold the plastic back plate to the motor are M3x 25mm (qty 2).
The screws to hold the back plate to the cage/frame are about 9mm long 3mm or #4 sheet metal or self-tap screws (qty 2) (not critical).
The screws that hold the fan to its mount are about M3x25, with M3 nuts of course (I used the M3 Nyloc nuts from the FT-5 build). (qty 2)
The screws that hold the Volcano duct to the cage are 3mm or #4 or #6 sheet metal or self-tap screws, one is about 25mm long, the other about 7mm long (1 each). Try to get a FLATHEAD one for the 25mm, so it doesn't stick out far below the duct. The small self-tap screws that hold the plastic back plate to the cage are 3mm or #4 about 9mm long.
For the Standard V6 duct, use an approximately 18mm long self-tap screw for the long one.
(If you want to get fancy, you could tap out the holes at the bottom of the cage for M3 or #4-40 screws, but self-tap seem to work well here at least with PET-G)
The Frame, Backplate, and Spacers are original designs done in Fusion360
The "Duct and fan mount" parts are redrawn in Fusion360, and are partially based on:
A duct design by 3D Genera: https://www.thingiverse.com/thing:2332177
A 50mm fan mount design by Onebaldman: https://www.thingiverse.com/thing:1738499