I’ve had a Rocky for donkey’s years and was wondering about using it as a single doser machine. The main issue I had years ago was getting the grind fine enough for some of my home roasts. One day, I stripped my Rocky down to its underpants to see what could be done.
The first thing I noticed when I placed the blades together was that the cutting edges were not close enough together when the flat surfaces were touching. Mmm, I wondered, what if I machined the flat surfaces to reduce the space between the cutters? I grabbed an old set of blades and ground them down a bit with a diamond hone (cheap to buy). The diamond hone is dead flat so the two mating surfaces of the blades were mating perfectly. Upon installing the old blades, which were still in pretty good shape, and still sharp, I was gobsmacked to discover that my Rocky was now grinding so much finer. In fact, 4 notches from the zero point, was the finest setting I needed, so I could go even finer, almost to a Turkish coffee grind if I wanted!
Wow, with the quality of the Rocky build and the power of its motor, I felt I was onto something. The next step was to remove the anti-popcorning attachment that sits above the blades. Easy to do, just unscrew it! As it happened, we had just finished a 1kg tub of honey. This tub fits perfectly into Rocky’s bean hopper and is tapered so that it can be used as a blower. Now, if I use the honey tub as a blower, the Rocky becomes a zero retention grinder. I just throw in my measured dose of beans and give a couple of pumps at the end, and voila, grinds out equals beans in, ie. Rocky Zero! I could hardly believe it.
Just one note of caution. There are a lot of non-genuine blades for the Rocky grinder. I paid the same price to a supplier for a set of these blades and was disappointed by the performance. make sure you get the genuine blades, with the Rancilio symbol on them.