Motorizing a grain mill

I picked up this motor recently at the suggestion of some fellow homebrewers online. I wanted to give a quick description of how I hooked it up to my monster mill for those who are interested.

The motor runs at 177 RPM, which is a good speed for milling grain. This makes it ideal for a direct drive grain mill without need for belts and pulleys. It’s about 1/9 HP, which seemed questionable at first, but the people who used it on their mills had no problem with it being underpowered. I don’t have a lot of room, so I mounted it to some fiberboard that I can place on my mash tun at milling time and carry down to the basement when finished.

To mount the motor and connect it to the mill, I used:

3/4 in. fiberboard, cut to 18X24
1/2 in fiberboard, cut to 12X12, for mounting the mill
Spider Shaft Coupling Hub, 3/8″ Bore
Spider Shaft Coupling Hub, 1/2″ Bore
Buna-N Spider for Spider Shaft Coupling Hub
4″ corner braces
4 1/4″ bolts, 1 1/2″ long, nuts and washers
4 1/4″ bolts, 1″ long, nuts and washers
4 1/4″ nuts, fine thread, for the motor bolts

The braces came with holes that fit the mounting bolts on the front of the motor. With the mill raised on the 1/2 in. board, the drive shafts were perfectly aligned. How nice!

Motor, with braces attached, lined up with mill

Gap for the mill output and mounting holes

Layout for grain output hole and mounting bolts on the main board

Motor and mill, mounted and connected with spider coupling

On the electrical side of things, I added a combo single pole/3-way switch so I could control both the power and the direction of the motor in case of a jam. The motor came with a big honking run capacitor, so I shielded that in a junction box to avoid any accidents on drunken brew days. I used a 16-gauge power tool cord to supply the juice. The motor itself came with a wiring diagram, but if you’re interested in how I connected it to the 3-way switch to provide forward-reverse options, let me know and I’ll draw up a diagram.

Finished, before adding the hopper

So far, I’ve had no problems with the motor driving the monster mill. It did about 5 pounds of grain in a minute in a test run, with no problems with starting up or stalling.

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  1. Well done sir!!! I’ve always said that laziness breeds creativity, and creativity is a necessity of a good brewer.

  2. Yep, Seriously awesome. Chris, can you remember about what you spent in total for the whole rig?

  3. Ben,

    It was probably $150 for the build+ the price of the bare bones mill. Monster sells various models from $120 up to $300 for a stainless 3 roller!

  4. I would like the wire diagram you made and used. ( I am pretty much copying)

  5. Hi i am not a member of your group but would really appreciate it if you could make a wire diagram. i have the same motor as you but i don’t know how to wire it. cap[asitor and all. I went out and bought a combo single pole/3-way switch too. thanks so much. nice job!

  6. No problem… here’s the link to the diagram:

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