My faithful Cimbali Jr grinder has developed a very annoying problem. For the past couple of months the grind adjustment knob has been falling off the shaft. I will be grinding away and THUMP! The adjustment knob falls off. It just pushes back on but the adjustment shaft looks like it is not protruding out of the case far enough.

The knob pushes back on but it bottoms out against the grinders' front sheet metal and will grind against it when turning. The knob just loosely hangs on the shaft. Not sure what happened. Does anyone have any ideas? Or better yet, could someone measure the adjustment knob shaft from the sheet metal to the end so I can see if something has slipped inside my grinder. Other than that, it is working as good as the day it came out of the box.

Mine is approximately 11/16" from sheet metal to the end, and the flat portion of the shaft where the knob pushes on is completely exposed outside the sheet metal. Hope that helps - there is a picture of the worm drive/shaft here (Cafe Parts) if you'd like to see how it looks without taking the hopper off:

http://www.cafeparts.com/Images%5Cbig%5C5020113.jpg

Ah this happened to me a few times with mine.

What I did was took a piece of double sided tape and put it around the shaft and got the knob to stay on.