Running just one Mini can be loud, but 3 at a time can be deafening! In an effort to make our office a little more conducive to things like reading, 3d modeling, or even just conversation, I did some research into noise reduction. My results:
http://www.ultibots.com/nema-17-damper-astrosyn-my17rmdamp/
GET THESE DAMPERS!
You only need ONE damper to make a remarkable, astonishing difference in the sound your printer makes. The key is to install that damper on the Y-Axis stepper motor (thats the one that moves the bed). This is by far the loudest motor on the entire printer, second only to the two Z stepper motors that typically only make a lot of noise when the print is starting and the bed is leveling.
I looked into installing the dampers on the other four motors on the Mini, but I ran into some problems and would love some advice.
The X-axis motor is mounted too close to the frame for installation. It requires a minimum of 6mm of clearance, and that simply isnt there. Cutting the frame or printing a new mounting bracket is needed
The extruder motor has a special plastic piece attached to the drive head that lets it fit perfectly into the herringbone drive. Installing the damper misaligned the gears. A new plastic piece will need to be designed and printed to use a damper on the extruder drive.
The most trouble I ran into was with the Z axis stepper motors. Not only are they the most difficult to access, I almost damaged the part that links the drive head to the long screw. Advice on removing the NEMA 17 motor from that coupling would be appreciated.
Thanks for reading!
-Rob
RMO printer/designer