Cheap DIY Option for a Motorized Grain Mill

[bschot]

Sweet, that is really promising. I looked on Amazon for a 6 amp power supply and it looks like they are little cheaper than the 5 amp models, 10 amp models are about $20. I had a thought, what is the peak draw on starting with grain? I know the lead/acid or lithium batteries can handle the momentary high draw but I don't know if the power supplies could handle it. It may not be that big a deal, just start the mill and then pour the grain in.

 

[bacgabe]

IIRC It was no more than an amp above the continuous draw.

 

[bruce_the_loon]

Has anyone tried using a windshield wiper motor, those are 60rpm and 50-70 lb-ft torque and run off 12V DC well. 2nd hand ones from a scrapyard should be $10-$20 at the most.

 

[bacgabe]

Interesting. It never occurred to me to mill them separately, but you do have a point. I guess I never noticed enough of a hit to my efficiency to think of it. I may give that a try. Thanks.

 

[N3Bruce]

I was thinking a power supply from an old desktop PC might do the job. I picked up the smallest one I had laying around (in this case a 250 watt ATX supply) and looking at the rating label, it says it is good for 8 amps on the 12 volt section. Just pull the yellow and black leads off of one of the Molex connectors for power. If your power supply has no switch on the back, you will need to wire the green wire going to the motherboard connector to a black wire to a switch. If the supply does have a switch, you will need to tie a the green wire to a black wire, then use the switch to turn the motor on and off. If you are using an ancient AT supply, verify the 12 volt section has adequate power, then just tap a yellow and black wire off of a Molex connector.

 

[N3Bruce]

I was thinking a power supply from an old desktop PC might do the job. I picked up the smallest one I had laying around (in this case a 250 watt ATX supply) and looking at the rating label, it says it is good for 8 amps on the 12 volt section. Just pull the yellow and black leads off of one of the Molex connectors for power. If your power supply has no switch on the back, you will need to wire the green wire going to the motherboard connector to a black wire through a switch. If the supply does have a switch, you will need to tie the green wire to a black wire, then use the switch to turn the motor on and off. If you are using an ancient AT supply, verify the 12 volt section has adequate power, then just tap a yellow and black wire off of a Molex connector.

 

[KudzuHighlander]

Sweet idea, my uncle used a treadmill motor (there will be lots of those for sale soon). The motor is DC and "dashboard" has variable speeds built in. I think is paid $10 for it at a yard sale.

 

[brandonlovesbeer]

I wish I could find a good DIY for an actual grain mill. Anyone got one? I just keep finding the same one with concrete rollers made from paint cans.

 

[camiller]

I know the monster guts wiper motor is 50-70 INCH-lb of torque not ft-lb. http://www.monsterguts.com/store/product.php?productid=17685

 

[MT2sum]

Great article - nice, clear instructions for DIY.
That Motor/gearbox is on eBay for $24.50 in case anyone is looking for one.
http://www.ebay.com/sch/?_nkw="John Deere Gator, Polaris 700 Motor"
I'll probably look to get one someday, but right now, I have other things more pressing - ....

 

[TheGoatman]

How on earth did you fasten this motor/gearbox to the plywood base? You say there's a plate on it, but it's hard to see anything when the pictures are all from the back. PS, for easy Canadian fitting to replace the harder to find PVC part: https://m.canadiantire.ca/#/products/productDetail/0632326P/false/false/false?selectedSku=0632326&quantity=1
Home Hardware has them too, along with all the other parts.

 

[bacgabe]

If you look at the first picture there are two screws on the motor/gearbox that are used to affix the motor/gearbox to the toy vehicle. I screwed the metal plate to the gearbox using those two screws (one screw went into an existing hole on my metal plate, but I had to drill a new hole for the second screw). I then screwed a piece of wood into the underside of the plywood base. That piece of wood created a perpendicular brace upon which I screwed the metal plate. Ultimately an L-shaped piece of metal would probably be better for mounting...I was just using what I had at my disposal at the time.

 

[BadNewsBrewery]

For what it's worth, I just tried doing this and powering it off a 6a adapter from Amazon -
https://www.amazon.com/gp/product/B01AJQ9G2C/ with zero luck. I think the inrush current is too high because it causes the internal breaker on the power adapter to click off, so I only get little pulses of energy out of the motor as the overload circuit clicks off and then back on. I'm going to try jumping to a 10a version.

 

[BadNewsBrewery]

The bigger power supply works great. I also figured out a way to shrink the adapter quite a bit. The shaft from the mill fits perfectly inside the hole for the axle on the motor. Using a piece of 2x2 square tube, I cut some notches out much like the original post, welded a plate on it, and then welded a piece of round tube to the plate, inside the square. I tapped a set screw into the round tube, so the whole thing slides onto the mill shaft. Then it was just a matter of making a mounting plate for the motor and I was off and running. Here are some photos of how I set mine up - thanks for the great idea!!
http://imgur.com/a/k9yvd

 

[Pash91]

I tried 2 different versions of this powersupply and have not been able to successfully turn the motor. It turns on briefly, then looks like it's shorting the PSU. The light turns off, takes a moment, then turns back on, turns the motor briefly and repeats.

 

[ChappysBrewing]

what size lovejoy coupling would that be exactly? Am actually doing your exact build since its a good price but instead of the vinyl tubing am looking at the lovejoy coupling. I have a monster mill which I guess shaft is either 3/8 or the 1/2 (will have to look at it again later) but as far as the 1/4 coupling to the shaft im trying to figure that piece out.
Thanks!

 

[dsletten2001]

What did you figure out regarding the lovejoy coupling? I am just starting to build this same setup but wanted to use a coupling instead of pvc. Thanks!

 

[TAPPER]

Which power supply are you referencing? Link? Sorry, but I'm having trouble following which one you're talking about in the conversation.

 

[veganbrewer]

People who have done this, how is it holding up? Can you post an image of the bracket you used to mount it?

 

[modobrew]

Here is my attempt at using a power wheel motor. I'm still finalizing the design, but it looks like it might work. I still need to drop some grain in to see how it performs. I designed (albeit roughly) and 3d printed the cog/lovejoy coupling. Pretty pleased with the fitment. Hoping it will hold up to the torque. I guess time will tell. The forward/reverse switch is temporary as I have one coming my way that will lock in place vs me having to hold the switch to engage. I'll try to update when I get it set up in a manner that is halfway functional.

Video file was too large to upload (youtube link here)