Suitable Grain Mill Motor?

[fraser_john]

Last time I brewed, I tried the old throw a little water in with the grains and crush it technique. Unfortunately, this sheared the shaft on my XD Falcon windshield wiper motor right off!!! Seems it made the grains a little firmer and the shaft of the motor was not quite up to it!

Anyway, I have been looking for something a little more appropriate. I have found a 950D series DC motor on RS Australia. However, I have no clue what the torque figures mean!

Any engineers out there that would be able to compare the figures with what a wiper motor might produce?

RS Australia 950D 148:1 Reduction DC Motor

The basics are:

Type Miniature Electric Motor Gearbox Combinations
Body Diameter 35.5mm
Input Current infotext 0.1555 A (No Load Current); 0.837 A (at max. Eff.)
Length 67mm
Output Ratio 148:1
Power Rating 6.21W
Shaft Diameter 5.98mm
Shaft Length 17mm
Stall Torque 6.061Nm
Supply Voltage 12
Torque 9664gcm​

They have others for different reductions and RPM rates at voltage levels, the 148:1 is 85 RPM at 12V.

Also, they have some nice timing belts and pulleys for about $15 each that could be used to connect mill to motor.

 

[Doogiechap]

G'day,
I'm pretty ignorant regarding torque figures but looking at the physical size of the motor I think you will have issues with the lack of power. This unit from Oatley Electronics might be a possibility ?
Cheers
Doug

 

[Tony M]

That motor is only 6.2 watt. I had a 65watt motor (10X the power) and if I wet the grain, that used to stall. I am now using a motor that is around 200 watt (about 1/4HP) and that is good.

edit: I see doogiechap is lurking. He can tell you what wattage those wheelchair motors are

 

[Doc]

That motor looks a bit low on grunt, so if it was to work probably wouldn't last long.
I use an old concrete mixer motor. 240 v 1/2 hp and about 1700rpm that with a couple of pulleys operates nicely at around 200rpm.

This isnt exactly what I have but is similar

Edit:
This is a closer representation

Doc

 

[Justin]

I've been using a wiper motor on my barley crusher for quite a while now, it still works well. My first suggestion is to maybe just buy or get another wiper motor and try again, it could be possible that the one you had might have had a weak shaft as a manufacturing fault or as you said it just might not have been up to the task. Anyway, trying a new one might be a relatively cheap option and could be a simple drop in replacement option. Might be worth considering.

Onto the torque requirements unfortunately off the top of my head I dont know what would be required or how to convert the figures. However, I can suggest going over to the Brewboard (www.brewboard.com) and doing a search for Bodine motors. Those guys have been using these geared motors to power a range of mills with great success and you should be able to find a figure for what would be a suitable torque range for a motor in this situation by searching the threads on that board.

Of course how much torque is required for your mill would have a lot to do with the designs of your mill. Things like roller diameter, roller width, gap setting etc would all effect the torque required to some degree.

Best of luck with it.

Cheers, Justin

 

[kook]

Of course how much torque is required for your mill would have a lot to do with the designs of your mill. Things like roller diameter, roller width, gap setting etc would all effect the torque required to some degree.

Best of luck with it.

Cheers, Justin

Not to mention what you're crushing with it. I've got a 3/4 hp 240v industrial motor driving a crankandstein. Crushing rye the other week was a challenge, even with that much grunt it still stalled the first time I attempted to crush with a (very) fine gap.

 

[user 384]

I have no clue what the torque figures mean!

My suggestion is take your mill, set it to it's finest gap and load the hopper with your hardest grain. Then get a bucket and hang it from the end of the mill handle. Begin to fill the bucket with water until the point at which the rollers break free and turn. This will give a very good representation of the maximum torque needed.

Next is to measure the amount of water you added. 1 litre of water is basically 1 kg, so if it took 3.5 litres this is equal to 3.5kgs. Then multiply this by the length of the arm on your mill handle. This will give you the torque you need eg 3.5kgs x 15cm = 52.5 kilograms per centimeter of torque. You can then compare this to the maximum power of motors. If the power of the motor is expressed in something like pounds per inch or newton metres (Nm), then use an online torque converter.

Cheers
MAH

 

[fw00r]

While we are one the subject...I have been thinking about a motorized mill with the idea of a washing machine motor. Any idea how much torque they might have?

I figure they would be fairly good for the use, 240v and have to push a 30+ cm barrel with wet clothes inside + water around.
(Front loading btw)

 

[Andyd]

I think I've got the opposite problem. I've got an old mulcher that has a buggered hopper, so I was thinking of salvaging the motor. Plenty of torque, but way too fast. I'll have to build a belt reducer or something.

Andy

 

[fraser_john]

I have a washing machine motor from a Hoover front-loader as well, but it has no wiring harness with it and has more wires than I could possibly imagine would be needed for an electric motor. From what I have read on this board, I would guess it to be a four pole motor with two speeds, which given its from a front loader kind of makes sense. Further, it has a big capacitor with it as well, but not directly attached to the motor.

I was going to give that try as well, but the wiring is too complicated. I might post a picture of it tomorrow and see if anyone can provide any hints to wiring it, seeming as its in the garage already and I have pulleys/belts already, it would be a $ saver.