This is a replacement carriage and e3d v6-compatible hotend mount for the Monoprice Select Mini. It supports a 40mm heatsink fan, 50mm radial part cooling fan, Prusa R3 angled fan duct and blower fan support, and GT2 x-axis belt. Parts are held together with M3 socket head cap screws and M3x4mm (1x for the fan duct) and M3x6mm (4x for the clamping face and 1x for the fan mount) hex standoffs hex inserts.
Updated October 22, 2018: Edited the M3 nut version to hopefully make bridging of the nut slots easier.
Updated October 12, 2018: Uploaded a version which uses M3 nuts instead of standoffs for fastening.
Note: There may be clearance issues between the fan duct and Z-tower due to manufacturing differences between printers. My R3 duct just barely fits without crashing on my modified V2.
Prusa R3 parts here: https://www.prusa3d.com/prusa-i3-printable-parts/
You will need an open GT2 belt to slip through the carriage. To reconnect the ends and tension at the same time I have uploaded a GT2 belt tensioner remix which uses M3 a socket head cap screw and nut. https://www.thingiverse.com/thing:3134656