Grinding Coffee Beans The Machine Shop Way

Okay, so you bought a bag of heavenly-smelling single-origin beans down at the hipster coffee shop, but forgot to have them ground. What do you do? If you’re [Jimmy DiResta], there’s no way you can run down to Walmart and pick up a grinder for $15. You commune with your tools and spend a few hours building a grinder from stuff lying around in the workshop.

This hand-crank grinder would make a great post-apocalyptic appliance, as long as we still have a way to heat water. [Jimmy] started with an old manual abrasive disc grinder, like for grinding metal, not beans.

After oiling it up to run without a hitch, he pulled out a couple of conical gears and got to work mounting one to the grinder shaft and the other to the business part of a vintage industrial light fixture.

We thought for sure this was going to be a burr grinder, but were a bit disappointed to watch [Jimmy] drill holes through a utility knife blade in order to make a blade grinder. Honestly, we’re kind of surprised that he didn’t machine some burrs, but the result is impressive and lovely nonetheless.

We love that the whole thing quick-disconnects from the grinder thanks to a custom cuff that holds the light bulb just so, we just hope that [Jimmy] gave that light bulb a good cleaning first. Grab a cup of whatever and check out the build video after the break.

Not exactly your kind of shop? You could always print an emergency coffee grinder.

31 thoughts on “Grinding Coffee Beans The Machine Shop Way

    1. Yes, I thought the same. I love to see people machining metal but sure wish he had made a burr mill. I realize that isn’t so simple (which is why burr mills cost so much).

      But, disregarding that, it is a clever build.

  1. I realize this is probably a one-off, this is a hacking site, and I’m not a safety nanny, but… really?

    Doesn’t stainless steel typically have chromium, and so only certain specific types of steel are rated for food preparation? (Noting the blades and possibly the screw hardware coming into contact with the coffee). (304 steel has higher nickel to reduce oxidation and corrosion?)

    Shouldn’t the food prep bits be sterilized before 1st use, or at least run through the dishwasher one time before first use?

    Is brass food safe, for various reasons relating to zinc?

    With all the adjectives of wholesome, natural, and fresh at the beginning of the video, is the build you really want to make?

        1. Did you see how close his fingers got to that spinning & unshrouded wheel when he’s turning the grinder? It must weigh 4-5 lbs, spinning at 1,000 RPM? Definitely take-your-finger-off inertia, clamped kinda sketchily to a tabletop.

          (But probably just fine for a 1x use video prop.)

          Compared to that, the food safety is a minor niggle.

          I’ll second that about leaving the key in the lathe chuck. Never seen one go ballistic, but I can only imagine…

          1. We had a.) key holders with a switch. lathe wont turn on without key. b.) large grids between machines to catch parts leaving the chuck at undesired moments.

            oh, and there is another scene when D. is using the file tool with his arm plus cloth leaning over the chuck. Never ever. even with tight-fitting cloth. never ever.

    1. The average cheap “vintage style” coffee grinder off of aliexpress or amazon will be made of either a zinc alloy casting, or stainless steel. If the former, it may include trace amounts of lead as well.

    2. Bruh, REALLY?

      Do ya think this an everyday use tool?
      Do ya think coffee ever got ground in this contraption after the video was made?
      Do ya think this video was made so you can go diy?
      Do ya think this video was made for any other reason than to draw customers to buy his coffee and soap?

      Safety nanny, no. A “know it all”….

    3. Yes, stainless has chromium but it does not come out of solution unless you melt or vaporize it. I just fast forwarded though but I didnt see any stainless. The blades are usually high carbon steel.

      I suppose I would wash it to get rid of any oils which I am sure he did off camera. But sterilization? Do you sterilize everything in your kitchen before cooking with it? Soap and water will be just fine.

      Brass is food safe, again, elements generally dont come out of solution in an alloy.

  2. “This hand-crank grinder would make a great post-apocalyptic appliance, as long as we still have a way to heat water.”

    You know it’s the end of the world when you can’t heat water.

  3. I have several old grinders like that, never thought of using them for anything other than grinding/sharpening.
    I had to put them away, my daughter loved making sparks with them, and it didn’t matter what she grabbed to make the sparks (such as antique hand brace auger bits).

  4. The light bulb is mentioned twice. It’s a safety enclosure for an incandescent light bulb. They seem to very trendy lately. The hipster bar and the sports bar and many others in town have them sprouting from the walls or in stalagmite formations above. They aren’t LED friendly due to heat enclosed by the glass.

    My daily grind is a quarter $ flea market luck. It’s an iconic Kitchen Aid art deco design topped by a big glass screw on “light bulb” with those classic straight lines and radial curves and a screw on lid on top. The only “hack” taking it apart for a clean and lube on the motor giving it another half century of service.

  5. “Okay, so you bought a bag of heavenly-smelling single-origin beans down at the hipster coffee shop, but forgot to have them ground.”
    At a true hipster coffee shop, asking them to grind the beans you just bought should lead you into the necessary discussion about how quickly aromas dissipate in freshly ground coffee and that you should always grind fresh.
    So, either the coffee shop in this scenario is just the typical faux-hipster place or you *did* remember to *carefully avoid* asking them to grind your beans… so they don’t end up grinding your gears.

  6. Reminds me of when the power went out at the lab, we took beans from the normal coffee machine, ground them up with a pestle and mortar and used a soxhlet extractor, flask, a big fat cooler and a bunsen burner to make coffee. You know, while it actually tasted awful in a way that was the best cup of coffee I ever had.

  7. on a more quality related note: D.s concept wont deliver reproducible results. everything would be at random due to filling, turn speed and duration.

    true coffee nerds know why we use slow cone grinders.

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