I have since moved on to a different design, while this mount worked well for me for almost a year, it limits access for necessary maintenance. I will keep it up here, but recommend exploring other options. Here is what I am currently using on the same slide: http://www.thingiverse.com/thing:291980 This is for anyone that converts to the PBC linear slide but wants to keep using the popular Jonas Kuehling's Greg's Wade extruder. Works only with the J-Head Mrk IV-B or another equally tall hot-end. For shorter hot-ends the shelf on the mounting plate needs to be moved lower and the cold end made taller for the motor to clear the carriage. I have uploaded the SolidWorks file for easy modification. There are too many hot ends out there to make a one size fits all solution since the shorter the hot-end the taller the extruder body has to be for the motor to clear the carriage. This is more of a personal solution for my specific set of hardware as a stop-gap until I move to a micro extruder. For a fan mount to go with this carriage see: http://www.thingiverse.com/thing:38893You will have to print a modified extruder body, I attached one sliced for .25 mm but you can render your own from the attached OpenSCAD file. I only changed two major things: set elevation = 13 from the default 2, and set motor_mount_rotation = 0. You only need to print a new extruder body; idler, gears, and hardware are all the same.