motorized grain mill - motor speed control?

[Frothy]

Hi Y'all

I'm planning to motorize my Corona grain mill, mainly because I already have RSI in my shoulder - but also because it takes ages to crush enough wheat for my wheat beers.

Here is an example of a mill using a washing machine motor from youtube->
http://youtu.be/070gK97L-0I?list=FLltzH ... Kb8LeCTM8w

Easy and inexpensive to get hold of the motors but they are good for 1000RPM
I'm wondering if anybody has any experience with these and particularly reducing the speed of the motor?

Can a regular power controller be used (phase angle as you would use on an element) or is some sort of variable frequency jobby needed?
http://en.wikipedia.org/wiki/Variable-frequency_drive

cheers

[LeeH]

A VFD will work if the motor you use can be connected correctly. Having quick look on eBay I would suggest you are better off getting a standard 3 phase squirrel caged motor and use that.

You will need a single phase 240V input VSD and a 3phase motor wired in delta.

Won't be cheap though even second hand.

If you need help programming the VSD give me a shout.

[Aleman]

Belt and Pulley . . . a 3:1 ratio of Diameters will bring you down to just over 300RPM which for a roller mill is round about where you need to be. . . . Now where to get suitable pulleys

[BenB]

I'd be traditional and use a power drill. Easily available, simple to clamp (in fact some come with a removal grip handle for the front of the drill which could easily be attached to a plank of wood as a drill mount. On low (screwing) speed these will often do about 150rpm which is from what I've read spot on (I suspect a few hundred rpm is the target- 150 or 300 probably makes diddly difference). Not sure on the attachment on the corona but if it's small you could even just put it into the chuck on the drill though it's tempting to drill a small hold and JB weld a short section of hex into the shaft and clamp the drill on that.

Advantages is the drill has a built in slow start option and most have a latch to latch the drill on IE use the slow start to get the drill moving then latch it on and have fun. You've still got a working drill at the end of it etc etc.

It's possible I'm sure to harvest bits from washing machines etc but it's going to be a faff and then you have to cover the motor because it will have exposed terminals etc etc.....

[themadhippy]

one word of warning, using motors at low speeds can cause them to get rather hot as the inbuilt fan aint providing enough cooling

[lord groan]

Motor pulleys?
https://www.machinemart.co.uk/shop/sear ... any/page/1

[ciderhead]

I always thought the target for mills was 100rpm?

[Frothy]

I already tried a drill directly on the shaft (corona mills aren't very big) and there are some videos on Youtube of people doing this.
Appears to be fine for grinding malt.
Wheat on the other hand is really tough and none of my drills were up to the job.

I've got a pair of pulleys and a V-shaped belt (will have to measure the ratio between these) just need to organize the motor end.

[BenB]

I suppose the belts of a motorised belt driven mill pose no more risk to the user than the mill itself (fingers and mills don't go) but they are a risk- things getting trapped between the belt and the pulley. A metal grill box to enclose it would be a precaution.
Interesting thread- I've got a bulldog mill (fingers crossed!) for Christmas and I'm a lazy so-and-so and I suspect I'll get fed up with hand cranking quite quickly so reading with interest. Then again, wheat? The mere mention of it makes generations of analy retentive Bavarians turn in their graves...

[Wonkydonkey]

I always thought the target for mills was 100rpm?

Yeh, I read up to 400rpm. But I think it was for the roller mill not the corona type mill, which I think was slower @100rpm-ish. When I was looking at all the options of mills etc.
I have roller mill and ("Aleman calls it a Chinese knock off") have never looked back.
On one occasion, I forgot to charge the drill. So I slowed it down from the usual low gear of full throttle which is approx 400rpm. Then I found it seemed to allow more time for the grain to fall into the rollers and crush more. Or to put it another way crush more at a slower speed and a bit quicker than the faster speed.

Anyway an ajustable speed control is important IMHO

but on another note, and something to think about. I got an old nicd battery drill from a car boot very cheap, I told the guy these type batties have a memory. He agreed and dropped the price even more, I think that was why he was selling it ( the cells can cost more than a drill)

Now I need to solder some wires to which ever bit I find easy ( in my case drill a hole in the battery cell case which has no cells in it now cos I unscrewed it and took them out) and just connect what ever power source the drill requires ( this drill is 12v so a car charger or the old drill charger will do). Now finding the time to do it is something else. If I did not have another drill maybe I'd do it quicker

Good luck with what ever route you take, but keep us informed, so we all learn from it

Wonky
Edit: maybe the drill charger connected directly to the drill won't have the power to drive the drill with the resistance of the grain. But i'm sure someone on here could tell you

[Frothy]

I have aquired an old Washing Machine & Tumble Dryer - so will be removing the motors from both.
Bearing has gone on the washing machine - but the motor is on a belt drive and doesn't appear to be affected.
There is a large pulley on the back of the drum so I will try and rescue this as well.

Will get her fired up and have a bash at first simply using a phase angle type Power controller, as you might typically use to adjust power on an element.
There is a capacitor in the washing machine - but all the videos I've seen the motor has started fine without it. i.e. here->
http://youtu.be/Hgf0apXNwSA?list=FLltzH ... Kb8LeCTM8w

[Frothy]

I followed the video for wiring - my pins were in a slightly different order - but the theory was the same as above video.
Scouring around this guy in link below is using a triac (phase angle) type controller to use a washing machine motor to power a metal lathe - check out the AVI video on his site.
Will try this out with my phase angle controller and hopefully upload a vid / pic's

http://www.calenterprises.co.uk/speed.html

[Frothy]

This guy says why bother reducing the speed - #livingdangerously

http://youtu.be/nOubu1yxM_4

[johnrm]

#stifflittlefingers

[Wonkydonkey]

#stifflittlefingers

+1 on that.....ooch my fingers.

Brings a whole new meaning to a finger-licking smash beer.