Has anyone ever motorized a hand grinder? I have a nice little gear motor that runs at 30 rpm; got to thinking about rigging up a poor man's Versalab robbing the burrs out of an Alinox that's sitting in pieces. Then I thought it would be nice and elegant to make some kind of stand I could pop one of the little rectangular Zass's onto that would turn the crank for me.

I really like the grind from my Zass's but it gets tedious when adjusting grind- I don't want to get some repetitive stress injury from making espresso shots .

Just curious if anyone has done something (or seen something) similar?

another_jim wrote:People have used variable speed hand drills to motorize Zass style hand grinders

I've been taking a DeWalt with me camping for years, and a hand grinder. Wasn't until recently that the lightbulb went on, and I couldn't be happier. There is something to be said about the organic experience of being in the desert with a cracklin' fire and a moka pot, grinding a peaceful morning cuppa. That goes away as soon as the other campers you're hanging out with taste your coffee.
Drill with appropriate sized nut driver attachment, low speed (torque setting) and preferably a variable speed trigger. Either that or a small electric screwdriver. Works just fine. Speed is not your friend.

One issue -- at 300 rpm, those burrs take around 15 to 20 seconds to grind a double, so if you're going at 30 rpm, you'll have to be very patient.

I get around (ish) 60RPM with the drill. Still faster than my first attempts by hand in the morning!

another_jim wrote:One issue -- at 300 rpm, those burrs take around 15 to 20 seconds to grind a double, so if you're going at 30 rpm, you'll have to be very patient.

You're thinking of the Alinox? I can't bring myself to part it out, so I'm on the hand grinder tack now. The cordless drill is a great idea! I'm thinking of making a stand with the motor driving a secondary shaft (I would probably step up the rpm to 100 or so with the pulleys). The secondary shaft would hang down through the frame and engage the crank shaft of the Zass. So the grinder remains unchanged, minus the crank. Simple dog clutch on the grinder and driving shafts so the Zass can be popped in and out without fuss.

Bit more brainstorming to do, will post a pic when it's cranking.

another_jim wrote:One issue -- at 300 rpm, those burrs take around 15 to 20 seconds to grind a double, so if you're going at 30 rpm, you'll have to be very patient.

Hand grinder burrs are optimized for leisurely turning. Cranking faster than ~80rpm (i guess somewhere thereabouts) doesn't give speed increase since the burrs turn too fast for the beans to drop in.
30rpm is slow though.

Bluecold wrote:Hand grinder burrs are optimized for leisurely turning. Cranking faster than ~80rpm (i guess somewhere thereabouts) doesn't give speed increase since the burrs turn too fast for the beans to drop in.
30rpm is slow though.

Yes I'd want it to come out roughly the same rpm as when I crank it which is a bit more than two cranks per second. I don't mind waiting, I've just never figured out a good way to hold the darn thing .

I know I read somewhere (here?) about a dude who was down in Brazil and visited a coffee grower; they were cupping and had a hand grinder screwed to the table and connected to a motor with a pulley. That's been in the back of my mind ever since . My wife would throw my gear out the window though if I started screwing grinders to the table.

A slightly oversized socket with a tamping wad of waxed string makes a good interface from the drill to the top of the grinder. A good low rpm drill works well that way.

-Cecil

There's some cat on Youtube doing a motorized demo... think I can find it right now? No but look for it, I saw it not long ago.

Rafael, they don't seem to be very cost-effective!

Arpi wrote:Maybe a motorized screwdriver with a rubber band.

At this point, just get the Versalab M3...