This is a hack around Joaz's MGS directdrive extruder design. As I was printing this Prusa i3 for some guy, out of PLA, I started hunting around for a solution to mount a fan to the hotend, which is common practice with PLA printed printers.
Seeing as there was nothing to be found, I hacked around this.
Joaz made this groovemount 'box' for his directdrive Prusa i3 extruder.
Seeing as it took normal J-Heads, I found it fitting to be adjusted for mounting below the Jozef/Greg/Wade's extruder that was in the Prusa i3 github.
Added the original scad... Keep in mind, if you print this out of PLA and are going to run a hotend at ABS temperatures, the housing -will- melt unless you add some isolation (that we didnt). We just printed one out of ABS with a fresh PLA one and swapped it ;)
Groovemount box for PLA Prusa i3 with 40mm fan mount