by jesawdy on Tue Apr 10, 2007 3:01 pm
How to find the Rancilio Rocky Grinder Zero point (applicable to many other similar grinders).
You need to start with an empty hopper. So either unplug your machine and scoop or dump the hopper or run the hopper empty before you get started.
VERIFY THAT THE MACHINE IS UNPLUGGED!
Remove the three screws holding in the finger guard and/or hopper. (I am guessing that many folks have removed the finger guard)
The hopper pulls straight up and off when the screws are removed.
You will see the brass upper burr carrier. Unthread it by turning it counter-clockwise until it is removed.
Clean out the grind chamber, upper and lower threads, the burrs themselves and the grinds chute. You can use a group brush, a grinder brush, a toothbrush, a toothpick, a vacuum cleaner, a slightly moist cloth, etc. I've noticed build up on the three brass carrier arms around the lower burr and significant build up on the lower threads in the grinding chamber.
Thread the upper burr carrier back on turning clockwise. I like to turn until it just snugs up onto the lower burr. Verify that it is actually touching the lower burrs by trying to turn the motor spindle; it should not turn (easily at least). If it does turn, you may be hung up on something or just meeting resistance in the threads; tighten it a bit more.
Back off the upper burr just a hair.
Carefully, plug the machine back in and pulse the grinder... turn the upper burr until you get a chirping sound of the flats of the upper and lower burrs touching. This is your zero point or the point at which the grinder will grind the finest.
Unplug the machine and replace the hopper and finger guard. You can orient the grind indicator sticker on the hopper in 120 degree increments, choose the one that puts zero closest to the grind indicator point on the front of the machine. Make a note of what the indicators says that your "true zero" point is.
That's it!
Jeff Sawdy