Zassenhaus Coffee Grinder Mod

Zassenhaus coffee grinders have been well-liked for generations, but their new product line has a design flaw. The plastic part that captures the outer burr is also used as a lower bearing for the inner burr, a terribly weak wear surface that creates unwanted play for course grind settings after only a few uses. This is apparently common to many conical burr grinders, but it need not be so!

Scouring the web for a way to remedy the loose burr problem affecting late-model Zassenhaus Coffee Grinders, I found just one set of instructions. Inspired by the suggestion to add a secondary bearing, I found a scrap piece of steel 1/32" (>1mm) thick to create a new bearing. 

The new bearing sits flush between the burr and the bean hopper, and accepts the burr shaft with a 5/16" center hole (actual diameter 8mm I believe). The bearing plate is 65mm long by 15mm wide, with a screw hole spacing of 50mm. It is critical to center the middle hole 25mm from each screw hole, so that the burr will be centered.

To install, first disassemble the mill. Remove the four top screws, take out the top assembly and remove the two burr holder screws. Insert the new bearing and reassemble, adding small washers as required to make sure the new bearing sits evenly. Photo 3 shows notches made in the plastic to recess the screw heads, making more thread length available.

In testing, the additional bearing does not appear clog or impede the feed rate of beans.

Happy grinding!