Reduce / limit / scale part cooling fan speed  

Reduce / limit / scale part cooling fan speed

Hello all.

I have an original Prusa MK3S+ and a Fysetc MK3S+ clone. Long time I was using both printers using same profiles in Prusa slicer, they were fully compatible on the g-code level. Recently I had to replace the part cooling fan on the clone. I ordered Fysetc 05B5015H fan, which was advertized to be a better alternative for the originally used XYJ05S5015H. Unfortunately the new fan is louder than the old one and I assume also more powerfull / faster. Using this fan the quality has unfortunately declined (which is resulting in a strange stringing, which wasn't there before and which is eliminated again, when the part cooling speed is reduced by 80%). To be able to use same g-code files for both printers simultaneously I'm looking for a possibility to use only the 80% range of the new fan. This should be transparent to the g-code so I assume that I can only modify the firmware or do some kind of hardware modification the the fan?

Have someome any idea where to start? I wasn't able to find concrete advices or tutorials which would match this use case. Basicaly I would be able to compile a new firmware, but I'm not a programmer. I would also be able to solder additional electronic components but I need to know which ones 🙂

Thanks in advance!