Makerfarm Prusa i3 Fan Mount

One recommendation to me was when printing PLA add a cooling fan to the black section of my hot end. I've had a only a few instances now where my extruder had spotty performance. One instance there was a bulge in my filament that could not go through the diameter. This required an additional disassembly of my extruder. It is my understanding the heat can conduct up the filament and get soft near the hob bolt. To avoid this I purchased a small 40x40 mm fan to provide cooling over the PEEK material of my J-head. Makerfarm recently came out with a new extruder but I have the "older" model so I had no holes in my extruder to mount my fan. I decided to make a fan mount that is retained by the two X-axis bolt holes used for the X-axis stop.

Front View with 2 holes for the fan

Back view where there is an angled section to match the wood
cutout of the X-assembly

I measured up the dimensions of the X-assembly and modeled it. I added 2 bolt holes on the side for the screws that attached it to the X axis assembly and matched the angled section of the X-assembly to prevent it from rotating about the bolts. There was one weal spot in my print where my extruder crapped out for a few layers.

Fan attached to mount

My motor has a 3rd wire which is used on a motherboard as a tachometer. In this case I will not use it but thought it be fun to have if I ever wanted to do anything with it. My motor is 12 V so I can hook it right up to my RAMPS board on the 5A power terminal. It will run all the time but I think I'll put a small switch in the line and mount it to my printer so I can turn the fan off and on. 

Fan mount attached to the X assembly

 I am really pleased with how it turned out. The weak section of my print actually broke on one side but still is really stable. I may print another one later. The fan does not blow over the hot end, only over the black section of my extruder. It is a very small amount of flow and should help. You can download the .STL file for the Fan Mount.