High Frequency audable tone from part coolinf fan  

High Frequency audable tone from part coolinf fan

All,

Since day one of building my MK3 i have noticed a high pitch tone comming from the printer. I did not have a clue where it was comming from but tonight i discided to investigate.

The printer was working fine and printing excellently however the tone was bugging me and i want my mk3 quieter than it already is.

I thoiugh the coolinf fan was the souce of the noise so i fired up pronterface and fired a bunch on M106 commands at the fan inorder to see if the tone changed with diffrenf values

Low and behold. I could change the tone based on the value used.

This leads me to suspect that the cuase of the problem is the freqency of the PWM.

So investigating the configuration.h i have found the following options

//#define FAST_PWM_FAN

//#define FAN_SOFT_PWM

#define SOFT_PWM_SCALE 0 this is already enabled.

This is where i need you help.

Does anyone know if i enable FAST_PWM_FAN will this only effect the part cooling?

Any recommendations?

Does anyone elese have this issue?