Grain mills hooked up to a motor..

Discussion in 'Homesteading Questions' started by Unregistered-1427815803, Feb 10, 2004.

  1. I thought I heard about a way to reduce the speed of a motor for use on a grain mill .... Like a reducer. I just bought a setup from another member here and its a good setup but I have to reconfigure it. Tension is real loose now. If too tight it turns too fast. I'd also like to come up with a way to EASILY and QUICKLY loosen the tension (like something spring loaded) so the belt tension isn't on and stretching the belt out.

    Any ideas?


    By the way ... My name is Mike and I live in PA. BUT YOU WOULDN'T KNOW THAT BECAUSE I CAN'T GET MY USERNAME TO WORK!!! This computer is about to go flying thru the window any second!!! That's OK ... it's a laptop.
     
  2. Ducks limited

    Ducks limited Member

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    I am not sure if you are talking about a home grain mill or a mill for animal feed but the same ideas should work for both.
    To change speeds, you could change pulley ratios. Might need to change belt size some to compensate.
    Can you mount the motor to where it could hinge and the weight of the motor will tension the belt? Thats the way my wood lathe is. It also has stacked pulleys to change speeds easily. Hope this helps you, Dave
     

  3. HermitJohn

    HermitJohn Well-Known Member

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    If you are trying to power a grain mill intended to be hand cranked, you really dont want it to turn over 50rpm. An 1800rpm motor would need a 36:1 gear reduction. This would be inconvenient to say the least with just two pulleys. You probably would need an intermediate jackshaft. A 2 inch pulley on motor going to a 12 inch diameter pulley on jackshaft would turn jackshaft at 300rpm. Now another 2 inch pulley at other end of jackshaft going to a 12 inch pulley on shaft of grain mill would get shaft of grain mill turning at 50rpm. I'd use hinges and gravity acting on weight of motor to keep everything fully tensioned.

    You also possibly could find and use a small gearbox.
     
  4. Mike in Pa

    Mike in Pa Well-Known Member

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    it's a 1/2hp 1750 rpm motor. 12" wheel and currently a 1 1/2" pulley on motor. What would a 3" pulley do? Excuse my ignorance.... just ain't gettin it.
     
  5. HermitJohn

    HermitJohn Well-Known Member

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    1.5 inch pulley on 1750rpm motor driving the 12 inch pulley will turn your grain mill shaft at 218.75 rpm. 3 inch pulley driving 12 inch pulley will turn your grain mill shaft at 437.5 rpm.

    Really any burr mill or stone mill shouldnt turn that fast. If mill is specifically designed to go faster than 50rpm, maybe, but I would think it would tend to scorch or glaze the burrs or stones. If you are converting a hand mill, be aware it probably dont have quality bearings if any at all. If you need faster milling a bigger mill with bigger burrs/stones is far better choice than trying to turn small mill faster.

    Just struck me about 12 inch pulley. This wouldnt be a Country Living mill would it? They have good bearings, but not sure you would still want to go over 50rpm. The pulley on these has a groove so they intend that it could be motorized. What do they suggest as maximum rpm? The only way to turn this machine with 1750 motor at 50 rpm short of custom making a 52inch pulley on the mill is to use an intermediate jackshaft. For example with 1.5 inch pulley on 1750rpm motor driving 12 inch pulley on intermediate shaft, the intermediate shaft turns at 218.75 rpm. NOw on other end of intermediate shaft you put 3 inch pulley and run belt from 3 inch pulley to 12 inch pulley on mill. This will turn mill at around 55rpm which should work ok. Now Country Living people are ones to listen to. They should know what good workable speed their mill would work at. My experience is from adapting a Corona hand mill to be driven by an exercise bike. It has no bearings but even if it did, I wouldnt want to try and push it over 50rpm. 40rpm maximum is best or geared down even slower for heavier grinding duties. Ok, I just looked and Country Living people recommend 50 rpm for cool grinding of all flours. And under no circumstances much over 100rpm. Here is link with suggestions. http://www.countrylivinggrainmills.com/country11.html
     
  6. Thanks very much O'solitary one :)

    The pulley on there is actually smaller. I measured 1.5" on the OD. The ID is about 3/4" +/-. That would put me at a little over 100 or so I guess.

    I'm going to try the configuration on the diagram you showed me ..I think. The belt is slipping now and I still want it slower anyway.

    Thanks a lot, Mike