80mm chasis fan nozzle and Sunhokey Prusa i4 cooling

thingiverse

One more fan cover to direct airflow out of print bed successfully in place. The holes and cover size are perfectly suited to standard 80mm fans. I implemented additional motherboard and chassis cooling on my Sunhokey Prusa i4 printer to resolve the stepper driver overheating problem once and for all. A complete solution involves: 1. Replacing tiny stepper driver chip heatsinks installed by default with larger ones. 2. Installing a fan blowing inside the printer directly at the MKS board on the right acrylic plate of the i4 chassis. 3. Cutting out a grill in power supply chassis and reversing the built-in fan direction so it exhausts hot air out of power supply effectively. 4. Cutting out a hole in the i4 left acrylic chassis above power supply so power supply fan blows directly through it. 5. Covering chassis holes with a pair of fan nozzles to direct airflow out of print bed precisely. The result is that I've monitored stepper drivers chip temperature and saw not more than 49C even under the highest possible steppers load. By the way, my stepper driver reference voltage is set to 1.2V (MKS v1.5 board). SketchUp sources are attached as well, containing two more designs. August 8, 2017: Nozzle design cleanup, STL file for left nozzle added. February 3, 2018: Left nozzle v2 added, suits better.