Radial print cooling fans for a CoreXY printer

I recently built this CoreXY printer - http://www.thingiverse.com/thing:1003119 - and decided that I wanted to mount a pair of 50mm radial fans for print cooling, rather than the original single ducted fan (I had modified the X carriage and the original one wouldn't fit).

I aimed for simplicity as far as possible; the parts are exactly the same on each side, and use very little plastic.

Update: 12/02/2016

I found that these 2 fans are too efficient for the poor hot-end, to the point where they would chill the hot-end when running at anywhere over 50%. Because of this I designed an air duct that pointed down by about 45 degrees; the fans still cool the extruded plastic but most of the air misses the hot-end nozzle block, which stays at the set temperature.

Update: 28/12/2020

Changes have been made following experiences over time - for a start, I have found that the PLA used for the mounting brackets became far too brittle as they aged, especially when the bolts were undone and re-tightened due to occasional maintenance. Eventually they snapped. Because of this I would recommend a more durable material such as ABS or PETG (which is what I have used).

I have also added a new rounded nozzle design - the old design worked but it was a pig to slice, with random holes appearing. This one seems far easier in both Cura and Slic3r. It also has a has a step incorporated that stops the nozzle sliding into the fan too far. I used a relatively soft adhesive to fix the nozzles into the fans.

Print Settings

Printer:

Prusa i3

Rafts: 

No

Supports:

Yes

Resolution: 

0.2

Infill:

100%

Notes:

The fan and X carriage mounts are printed in PETG - I got better-quality results by laying the fan mount on its side before slicing. Printing it in the obvious way (fan side down, post upwards) seemed to leave the top post very weak - but that may be my printing technique! ABS would also work, if you can print successfully using that material. PLA gets too brittle over time.

The nozzles are printed in ABS as each one lives so close to the hot end - no support required as they are printed with its large open end flat on the bed. I recommend printing 2 at the same time so that neither gets overheated.

Note that the nozzles have a slight offset as the fans don't quite point at the hot-end nozzle - but these fans produce so much airflow that any misalignment is irrelevant.

Post-Printing

No special requirements after printing - tidy up the pieces, use a 4mm drill bit to make sure that the holes are clear, screw the small bracket to the underside of the X carriage, screw on the fan bracket, then connect the 2 together.

I used a dab of glue to hold the nozzles in the fan outlets - yours may fit firmly enough not to need the glue.

Once mounted, move the carriage slowly until you are sure that the fans do not collide with anything.

Category: 3D Printer Parts