Grinding grain

chris25 · Post by **chris25** » 17 Apr 2009, 12:17

Guys, I have two manual grain grinders which I use frequently, but to be honest I'm getting fed up with the bloody things.

They provide very good exercise but take ages to process even a cup of wheat!

Makes me think that in a survival situation there maybe EROEI issues.

For that reason I am looking for a rugged, reliable electric mill.

Of course this creates an issue- what happens in blackouts?

Any idea how I could overcome this? I know it sounds crazy but is there any way of setting up PV panels to provide leccy to grind grain?

Almost wished I owned a windmill lol.

DominicJ · Post by **DominicJ** » 17 Apr 2009, 12:46

Probably, but I'm not sure its going to be worth the effort. An electric mill uses about 450w
Either you can generate a lot of electricity from solar, in which case you'll have a battery bank ect and dont suffer black outs, or you cant, and are stuck with a hand mill.

I'd be very very very surprised if hand milling was negative eroei

Post by **adam2** » 17 Apr 2009, 13:25

It would not be a good idea to connect an electric grain mill direct to a PV array because the available power is too variable.
Either the mill would be ineffective in non-optimum conditions, or it would be overloaded in bright sunlight.

One could of course power an electric mill from a PV and battery system. Either use a standard line voltage mill and an inverter, or go 12 volt.

For a mains voltage mill rated at 450 watts, I would suggest an inverter of at least 1,000 watts in order to allow for starting surges.
Presuming a 12 volt system, the average current drawn from the battery will be about 45 amps, though the cable and fuse should be about 100 amps.
This suggests a minimum battery size of several hundred ampere hours.
Depending on how much use is to be made of the grain mill, a PV array of from 100 to 250 watts should be sufficient.

Alternativly you could fit a hand grain mill with a 12 volt electric motor, some types of hand mill have a belt groove on the drive wheel, in order to allow belt driving from a external electric motor.
A certain amount of technical knowledge would be required to do this, but it is probably the best option.
Take care not to run a hand mill too fast or the flour becomes heated and spoiled.
The power requirement is much less since hand grain mills are designed for efficiency, therefore a 100 watt motor might suffice. That is only about 8 amps from a 12 volt battery, suggesting a minimum battery size of about 100 A/H. A suitable PV module might be about 100 watts.

Whichever solar option is chosen, remember that it is easier to store flour than to store electricity. Therefore, so far as possible, build up a stock of flour when sunlight is plentiful, and draw on this stock in dull weather.

If your concern is with short term or rota power cuts, then simply keep a stock of ready ground flour.
If you fear a longer term power problem, then solar is probably the best option.
Having determined the optimum solution it would be well to obtain a complete spare grain mill, and additional stocks of the wearing parts, and a spare motor.

Small grain mills can also be belt driven from a petrol or diesel engine. This is most unlikely to make prudent use of fuel, unless an engine is being run for water pumping or battery charging. If the engine is not fully loaded, then a grain mill could be driven in addition at very little extra fuel cost.

contadino · Post by **contadino** » 17 Apr 2009, 14:54

Is there a mill local to you? There's one in each town here, and ours will mill a quintali (100 kilos) for €3 (which you can pay for in grain.) You drop it off in the morning, and collect your sack of flour and sack of bran at lunchtime.

Post by **adam2** » 17 Apr 2009, 16:10

contadino wrote:Is there a mill local to you? There's one in each town here, and ours will mill a quintali (100 kilos) for €3 (which you can pay for in grain.) You drop it off in the morning, and collect your sack of flour and sack of bran at lunchtime.

That could be very useful while times are normal, but might not be available or sensible in an emergency.
In case of food shortages or panics I would not want to admit to owning 10KG of grain let alone 100KG.

contadino · Post by **contadino** » 17 Apr 2009, 16:25

adam2 wrote:
contadino wrote:Is there a mill local to you? There's one in each town here, and ours will mill a quintali (100 kilos) for €3 (which you can pay for in grain.) You drop it off in the morning, and collect your sack of flour and sack of bran at lunchtime.
That could be very useful while times are normal, but might not be available or sensible in an emergency.
In case of food shortages or panics I would not want to admit to owning 10KG of grain let alone 100KG.

You're being a little paranoid there. By it's very nature, 100 kilos is pretty difficult to hide as it grows outside and covers about 400 sqm. Fortunately wheat's main defence is that it's not very easy to nick under the cover of darkness.

peakprepper · Post by **peakprepper** » 17 Apr 2009, 19:23

I will be making an adaptor shortly to use my grain mill with a cordless drill.

Not perfect, but at least I will not have to have AC available at the time I wish to do some grinding. Also I have 3 x batteries for my cordless, so should be fairly stress free.

woodburner · Post by **woodburner** » 17 Apr 2009, 20:25

Why not use the mill as a load an an exercise bike? Or any other bike.

Post by **adam2** » 17 Apr 2009, 21:08

woodburner wrote:Why not use the mill as a load an an exercise bike? Or any other bike.

This would involve a certain amount of mechanical complication WRT to selecting the right pulley sizes to drive the grain mill at the optimum speed, it would however be a good long term solution.
Remember that a hand grain mill is intended to be powered by one arm, and not both legs ! Take care not to drive it too fast with the risks of breakage or overheating.
Many hours of sedate " cycling" would be better than a short all out effort.

I have never heard of a cycle powered wheat mill, but cycle power is used in Africa for grinding maize and dried beans.

DominicJ · Post by **DominicJ** » 20 Apr 2009, 08:54

Milled flour begins to lose nutritional benefit immediatly, or so the mill site I have book marked says.
The carbs arent going anywhere, but the vitaminy oils are.

waermund · Post by **waermund** » 20 Apr 2009, 10:20

As part of my groups Anglo Saxon re enactment kit we have a quern stone (made in derbyshire - circa £150) which is ideal for grinding any type of grain during a power out situation. It is labour intensive (typically 8 - 9 passes through the stone to get from grain to flour) - but hey labour intensive is the future.

woodburner · Post by **woodburner** » 20 Apr 2009, 11:06

peakprepper wrote:I will be making an adaptor shortly to use my grain mill with a cordless drill.

............ I have 3 x batteries for my cordless, so should be fairly stress free.

With a hand mill, it takes around 1/2 hour to grind enough flour for a loaf. Even then the flour gets warm. You will not be able to shorten this time significantly without the flour heating and degrading. So you will need 1/2 hour of battery power. That's a fair bit, and quite a caning for the batteries. A battery drill would be better for things that are difficult by hand, like drilling holes.

You could connect a 12V car battery to your drill for longer life, but then there's the gearbox. It was not designed for lengthy running periods.

Where ever you look there are problems. Solutions which are often in use in third world countries.

RenewableCandy · Post by **RenewableCandy** » 20 Apr 2009, 15:48

waermund wrote:As part of my groups Anglo Saxon re enactment kit we have a quern stone (made in derbyshire - circa £150) which is ideal for grinding any type of grain during a power out situation. It is labour intensive (typically 8 - 9 passes through the stone to get from grain to flour) - but hey labour intensive is the future.

Seen one in action at the Jorvik Viking bash in February, and of course had a go. Blimey it's tiring! Wonder if you actually get the calories back from the flour at all?! If not, I could go into beesknees selling them as Slimming Devices

!

Millers, in the olde days, were notorious rip-off merchants, or so says the exhibition at Skidby Mill: apparently Conservation of Mass doesn't apply to milling (not sure why!) so you couldn't check, using weight alone, whether or not a bit extra had been purloined. And you couldn't take your grain elsewhere because of estate rights or somesuch.

DominicJ · Post by **DominicJ** » 20 Apr 2009, 16:09

And you couldn't take your grain elsewhere because of estate rights or somesuch.

I was unaware that had applied in the UK, but it was one of the big issues when the froggies broke out the guiloteen

RenewableCandy · Post by **RenewableCandy** » 20 Apr 2009, 16:12

DominicJ wrote:
And you couldn't take your grain elsewhere because of estate rights or somesuch.
I was unaware that had applied in the UK, but it was one of the big issues when the froggies broke out the guiloteen

I only know that it applied here in (what subsequently became) the People's Republic of Yorkshire.

Guillotine

/pedant (for now...)