I started the printer this AM to find the 40MM extruder fan studdering along at a reduce speed. I wasn't sure if it was a part about to fail or something I had done, specifically changing the PWM setting in the firmware to reduce fan vibration, noise and add some ability to change the fan speed during printing (fan would shut off if not at S255 before the PWM change). After reading many posts about the PWM setting and how some were finding good results by bumping the number up to 400, I decided to give it a try (a fault of mine as I never seem to be able to leave well enough alone). It worked as others had described, reducing the noise and vibration (which impacted the surface finish of the printed parts). The ability to change fan speed was limited to S245 - S255, not as much as I had read, but something. My worry is that by altering the firmware I may be reducing the life of the fan(s).
As for fixing the present problem, I dis-assembled the fan assembly and cleaned both the fans and the area around the extruder. I tried the fan again with no change. So I employed an old "backyard mechanic's" trick and removed the label on the 40MM fan, exposing the end of the impeller shaft. I then placed a drop of 3-1 oil on the shaft. I worked the impeller back and forth by hand and then restarted the printer. The fan spun the full speed and showed no signs of the previous studdering problem. I let it run for a bit then dabbed as much of the excess oil from the pocket and reinstalled the label. I removed 4 of the 8 "lugs" on the fan cover hoping that the addition opening would relieve some of the force needed to spin the fan.
- Modified fan cover, lugs removed
- DSC_0659.JPG (188.63 KiB) Viewed 4205 times
- Another view
- DSC_0660.JPG (191.99 KiB) Viewed 4205 times
Mike H.