40mm right angle fan adapter for 10mm fan mount

prusaprinters

The original MK3S carriage and some third party (i.e. Bondtech) carriages allow for only a 10mm depth fan on the left side, the hot end fan. Problem is that 40x40x10mm 5V fans with tachometer signal are not common, you need to buy them from a printer specialist or large electronics distributor. I wanted to use various fans I have that were not specifically designed for the printer but work just fine.When choosing another fan you must use a 5V fan. The more common 12V fan will not work. Also a fan with tachometer signal is highly recommended. The Noctua NF-A4x20 5V fan will work and moves slightly more air than the 10mm Noctua that was supplied with my printer. A Sanyo Denki “San Ace 40” 109P0405H701 is also a good choice, moves significantly more air, is louder, but still low enough current.To make all these fans fit I needed to first make a duct and then to modify it by cutting away various parts and repairing the duct around the cuts. There is a cut in the outside radius of the duct to clear the left size Z axis screw and the taper continues to avoid conflict with the left side stepper mount. There are also vertical cuts to allow a screwdriver to access the bolts that hold the duct to the carriage.To fasten the fan to the adapter four M3 brass heat-inserts are used. If you don't have any heat inserts then M3 bolts will fit very loosely but are fine provided you can get some nuts on the back of those bolts, you should be fine with the Prusa needle nose pliers from your kit.