What is this NOISE?!

[Jules]

You talking about the grinding noise at the start and end? Sounds like the fan is running rough…it might be unbalanced and need cleaning.

Instructions here:

Caution: Dirty Pictures....or...How I Cleaned the Exhaust Fan

Update: 12/14/2018: Happily, the Glowforge crew has released an “easier to implement” cleaning regimen for the exhaust fan now…instructions for how to do it involve purchase of a special non-flammable degreasing spray cleanser and use of a special cleaning mode of the software…instructions here: Written up below is the old way that I was doing it…it’s a fairly labor intensive alternative that has worked very well if you are willing to keep up with it as you go along and not let it get …