The design is a simple ducted blower (radial) extruder fan which can be used to focus cooling exactly on the extruder nozzle area. The assembly uses:
- A 50mm x 15mm 12v DC blower fan model 5015S
- A short length (about 80mm) of flexible ducting cut from 10mm outside diameter electrical conduit
- A short length (about 70mm) of heavy gauge copper wire (ie about 1.8mm thick from some scrap power cable)
- A couple of small printed ABS parts
The photos show the assembly components and the blower fan mounted on the Wade extruder. In this case the printer is a Robo 3D
The parts are an interference fit in the blower outlet or can be glued/siliconed.
The fan assembly is screwed tightly to the unused screw hole on the extruder stepper motor and can be adjusted up/down. Adjust the length of the duct and angle of the copper wire to focus the cooling.
To make sure the assembly moves only when you want it to, use a rubber washer(or similar) between the fan and the stepper motor.
There are no other mods to the extruder assembly required and the stock fan should not need to be removed. A extra pair of light duty wires needs to be run back through the extruder loom to the Ramps fan connection terminals. Might be useful to have a switch to turn each (or both) fans on/off.