Layer Cooling Fan Bracket for Geeetech Prusa I3 by DougInAZ

Last crawled date: 3 years ago

This is a set of items to add a Layer Cooling Fan to a Geeetech Prusa I3 printer or others with similar extruder brackets. The fan duct is not included in these parts. Thanks to AndrewBCN for the inspiration and providing 3 very nice fan ducts. Actually there are 4, but it doesn't look to me like the wrap-around nozzle would work on a dual extruder setup.
Select from the 4 duct styles available at: http://www.thingiverse.com/thing:540716 , Configurable 40mm fan duct / mount for Wade's extruder.
The parts here include:
A bracket that attaches to the mounting holes on the printer extruder mounting bracket that were intended for a stepper motor cooling fan. The bracket contains two tracks that allow the fan (and duct) to be moved in the X and Z axis to position the duct near the extruder nozzle(s). There are two bracket variants available for use with both single and double extruder mounting brackets, depending upon your printer configuration.
A horizontal slider that fits in the dovetail of the above bracket, and contains the track for the vertical slider.
A vertical slider that fits in the above vertical track. The cooling fan duct (and fan) attach to this piece.
Of the 4 fan ducts available at the referenced Thing, I used the V3 bracket as a first try.
There are a couple different sizes of Z-brackets to connect the fan duct to the Z axis slider, for use to fit various configurations.
The horizontal slider has two holes for screws to fasten it to the track. Only one screw is necessary, depending on how it is positioned in the track.
A couple notes on the fan duct: The tip of the V3 duct which I printed, is only one perimeter wide, and can be delicate. It may have holes in it if your printer under-extrudes, as mine did at the time. You can beef it up with Superglue to fill any holes and stiffen the thin areas. Also, if it is positioned close to a MK8 type extruder head, it may soften due to heat radiated from the extruder, when the fan is off or on low speed. Gluing a piece of aluminum foil on the tip of the duct may prevent damage. A flexible adhesive like silicone rubber or latex caulk may work, as well as superglue.
The duct can be mounted using the holes that are formed when it is printed. The fan guard also contains mounting holes, so one set of mounting holes or the other may be cut off depending upon what works best for your printer. I ended up using the fan guard mounting holes for attaching the fan and duct to the bracket, and then later switched back to the mounting holes on the fan duct when I changed the orientation of the extruder block.
All in all, it works well and is acceptably stiff with the recently added stiffener. Maybe you can improve on the whole thing!
Update 12/3/17 I added a longer arm (zarm5), which I needed when I changed the mounting of the horizontal extruder mounting plate.