(To customize this design click on the Open In Customizer link here) This bracket is attached to the left side of stock Makerfarm Prusa i3v extruder and it is used to cool the workpiece layers before printing the next one. This improve printing of pieces with small area layer such as the test STL file attached here. To install attach the fan to the bracket with two M3x12 screws attach the bracket to the left side of the extruder with a M3x20 screw, replacing the existing M2x16 (sticking a tape below the extruder to keep the nut in its place makes things easier) and wire the fan to the Ramps D9 (+) and (-1) terminals. You can control the fan from your slicing software (e.g. Slic3r) or from the Marlin's Control menu (note that fan speed is updated only when you click the rotary switch). I printed with PLA (material support disabled) and didn't notice any heat issues from the extruder. (note that I didn't have a M3x20 so used a M3x30 with a 10mm spacer, this is why the screw in the pictures is longer than should be). The fan should be oriented such that it blows the air toward the workpiece. Included here is also a OpenSCAD parametric source file so you can tweaked STL files if needed. Note that this fan doesn't replace the main fan that cools the cooling fans above the nozzle, it is intended to cool off the workpiece.