I had an unusual problem on my first roast today. The roaster lost a lot of beans after charging… maybe 40 gms. Not thru the door but thru the escape path for chaff at the bottom of the faceplate. Shortly afterward the drum started making a horrible scraping noise like a bean stuck against the drum. The noise was at the rear of the roaster and was accompanied with forward movement of the face plate… it bulged outward a tiny bit. About the time I dumped the beans the noise suddenly stopped. After cooling I winnowed the beans to get rid of chaff and as I did I spotted 3 un-roasted beans, each with a black spot or 2.
After thinking about it, I believe the beans were stuck between the rear of the drum and the back plate. That would (I think!) explain the rhythmic forward bulging (0.020"?) of the face plate. I was dreading having to remove the drum to get the trapped beans but they seem to have found their way out.
Other than scaring me out of a couple years of my retirement I got a nice surprise out of it all: the roaster now runs quieter than it ever has… essentially silent without beans. Must have tweaked something a tiny bit.