Mill Motors

[WarmBeer]

FYI,

Yes, the MM2 (Monster) 1/2" shaft is d-cut. There's 3 slight cuts around the circumference, designed to fit the three collar fingers of a standard power-drill head. I can drive my MM2 using a Ryobi 18v cordless drill, although it smells like its working hard, and I don't want to shorten the usable lifespan of the drill too much. My corded Matsushita does a better job, but it is still straining the motor in ways it's not designed for.

Less speed, more torque is better for gracking grain, so if you've got something that does this, it's much better than looking for high revs, low torque.

Usually, most people will be milling grain in a dry environment. I've heard of people pre-moistening their grain before the crush, but they would be in the minority, and would probably be capable of waterproofing the motor themselves. You can assume a dry environment.

Hi everybody!

MHB, I didn't want to come across as a spammer lol, I know what its like when trash invades forums, it's just not a nice thing to see or put up with, so I though I would just introduce myself in the hope my customer who rang might see the message and give me his details!

At the moment I'm thinking of between a 400-500w motor to give an output of about 300-500 RPM with about 15-17Nm of torque...

That would give more speed and power to the mill, but I don't know how the mill would react to a faster crank speed... ie will the grain sail around the room? will the increased torque put strain on the mill if someone gets ambitious?

Is there any moisture where the motors will run? should I try and find a cheap anti shock coupler to go from the motor to the 3/4 shaft from the monster mill? what is the shape of the monster mill shaft? is it d-cut? or round? also I'm thinking of a mount that will let you sit the motor parallel to the mill for convenience and ease of setup...

Theres always so many unknowns when trying to get a motor suitable for a particular purpose and cost always plays a big factor and obviously I want to get it as cheap as possible so people can save some money and enjoy good value, but its better to have something everybody can setup easily rather than a few of the more creative people retrofitting random products.

And it never ceases to amaze me what people can accomplish when they set out to achieve something.

People are always welcome to pick my brains. Good service always starts somewhere!

Cheers!
John

 

[pb unleaded]

Hi John,

Would it be possible/efficiant to use a gearbox only, titan AC gearhead or planetary gearmotors, maybe 20:1 reduction ratio? and then couple these with a (cheap) power drill?

Thanks

 

[komodo]

Good to see you getting involved to help out some brewers motiondynamics.
Maybe some of the NSW brewers could pop over to your store and show you exactly what our mills look like (maybe someone with a MillMaster and someone with a Monster) and you can see exactly what we are up against.

Personally I went a 4 pole 750watt 240V cap start / car run motor @1400ish RPM with a 10:1.25 reduction using "A" type pulleys and a cogged "A" type belt. Works a charm for me and set me back about $260ish?
That said if I could've got a direct drive motor / gear box setup I would've preffered as the safety aspects of the pulley setup worry me a bit with little tackers around (not that I have any yet - but I'm hoping that my milling setup will out last me!)

 

[dicko]

Hi all,

Welcome to the site motion dynamics.
It is good to see a supplier willing to go the extra yards these days to satisfy special needs.

Now I dont want to begin a flame war re coupling v belt drive but it was the general consensus a while ago that belt was thought to be the more suitable for the fact that if the grain to be crushed had a foriegn object (stone) in it then it would jam the rollers and cause the belt to slip rather than if the drive was solid.
I have a belt drive on mine and I have actually had this happen and was very glad that the belt slipped.

Just another variable and food for thought.

Cheers

 

[Ducatiboy stu]

Slightly off topic :icon_offtopic:

With regards to moistening the grain, you only need about 150ml of water per 5kg, so waterproofing is not an issue there. Moistened grain still needs a lot of torque to get it going. Them main reason for doing this is to keep the husk intact, but still allowing the grain kernel to be crushed, giving better sparging and eff %. You only want to make the husk moist, not wet

 

[motiondynamics]

Hi John,

Would it be possible/efficiant to use a gearbox only, titan AC gearhead or planetary gearmotors, maybe 20:1 reduction ratio? and then couple these with a (cheap) power drill?

Thanks

I wouldn't bother, honestly why hack something together when you can get something complete.

Hi all,

Welcome to the site motion dynamics.
It is good to see a supplier willing to go the extra yards these days to satisfy special needs.

Now I dont want to begin a flame war re coupling v belt drive but it was the general consensus a while ago that belt was thought to be the more suitable for the fact that if the grain to be crushed had a foriegn object (stone) in it then it would jam the rollers and cause the belt to slip rather than if the drive was solid.
I have a belt drive on mine and I have actually had this happen and was very glad that the belt slipped.

Just another variable and food for thought.

Cheers

As for the slippage, it might be possible to get a clutched coupling to get around this issue. Out of curiosity, how often do you all run your mills? is it daily? once a week?

 

[razz]

I use mine about once every 6-8 weeks. I use a Millmaster from Mashmaster. I hand crank about 8 kgs of malt in 5-10 minutes.

 

[Supra-Jim]

I wish i had enough time to brew daily!!! I think you'll find we all pretty much run the mills each time we brew. maybe once a week, fortnight or monthly etc.

Cheers SJ

 

[Sammus]

mine'd have a go about once a week I reckon, but it serves some of the locals too. Maybe 2 or 3 batches per go, which is about 5min runtime.

 

[pdilley]

Duty time is pretty low. I went the AC motor from washingmachine route. Everyone has a dead one somewhere so motor was free for hauling away the machine. Costs are a hundred or so for custom cast pulleys (cursed 12mm shaft) and the included board to make the top of the grain mill bench and motor housing. Belt tensioned is applied at most twice a month for 5 minutes or less so I'm not fussed about bearing wear. The washing machine is belt driven so the motor was matched to changing torque / loads so I have multiple speeds and fully reversible through a simple switch to control speed and torque and direction. With large mill rollers I am the type of customer in the very low shaft rpm market. I would however have been interested if you had a whole package offering. Missing from DC motor costing is AC-DC power supply to provide a constant needed current under loads which adds costs to the DC solution. AC has benefit in that regard of just plug it in and go. I have a flour mill that also uses belt driven pulley drive but as with anything with a shaft a coupling solution would be available for it. So one thing to keep in mind is couing flexibility in case of a need to drive more than one mill or device (non concurrently) and you'll appeal alot to the home milling crowd or those who tinker and need a good drive system for their projects.

Cheers for stopping by and helping everyone out,

Brewer Pete

 

[motiondynamics]

Hi Brewer Pete,

You are correct, Power supplies for the DC range is something I didn't even bother to look at due to the excessive costs of high current supplies.

At the end of the day I think the absolutely cheapest way out will be straight shaft motors. The clutched couplings and what not all add to the cost of a unit I'm trying to keep really really low and with the different ratios people all seem to require I'd have to buy a massive amount of stock to keep the costs down and I don't think the sales would ever add up to the costs.

The interest has been great from the forum members and the information provided has been invaluable. But because of the sheer variety I may just look at the straight shaft output with variable pulleys. Its just going to be much cheaper for all involved. A bit more mucking around, less efficient but a working option nonetheless for those that require something budget.

I thought you all used the mills a lot more than you actually do , so the power usage isn't going to be as noticeable as I originally thought it would be.

I'll bring in a heap of motors, pulleys and some belts. That way I can help everybody for a cheap cost!

 

[raven19]

I thought you all used the mills a lot more than you actually do , so the power usage isn't going to be as noticeable as I originally thought it would be.

We all wish we could brew nonstop I am sure - but the liver is holding us all back!

I am also watching this thread with interest and look forward to seeing options put forward.

Cheers.

 

[Batz]

Hi Brewer Pete,

You are correct, Power supplies for the DC range is something I didn't even bother to look at due to the excessive costs of high current supplies.

At the end of the day I think the absolutely cheapest way out will be straight shaft motors. The clutched couplings and what not all add to the cost of a unit I'm trying to keep really really low and with the different ratios people all seem to require I'd have to buy a massive amount of stock to keep the costs down and I don't think the sales would ever add up to the costs.

The interest has been great from the forum members and the information provided has been invaluable. But because of the sheer variety I may just look at the straight shaft output with variable pulleys. Its just going to be much cheaper for all involved. A bit more mucking around, less efficient but a working option nonetheless for those that require something budget.

I thought you all used the mills a lot more than you actually do , so the power usage isn't going to be as noticeable as I originally thought it would be.



I'll bring in a heap of motors, pulleys and some belts. That way I can help everybody for a cheap cost!

Your giving out some good info here, much appreciated, is it possible for you to post a few pictures of the motors you recommend?

Cheers
Batz

 

[motiondynamics]

Well the AC motor I considered is already posted but it has the gearbox on it which the manufacturer will have to remove and make the output of the motor a straight keyed shaft rather than the existing pinion(helical) shaft. Then I'll find some pulleys for both the motor AND the mills in the ratios people want.

The DC is turning into a nightmare because apparently to change the ratio of a motor geared from a bike to a milling machine means entirely redesigning the outer casing to accommodate the additional gearing yada yada. Don't worry, I never give up. I'll find the best solution if it kills me.

 

[Cummins]

I am interested in a geared motor & coupler (AC or DC) for direct drive, definately not pulleys.
I have the unusual 12mm Shaft/4mm keyway that has been previously mentioned. Watching with interest.

 

[QldKev]

What spec did the AC motor end up at? Why I ask is you mentioned 350-400w

Now I believe watts to hp = 746w to 1 hp

Looking at a sample motor is rated at 0.25hp (this is an old motor)
but draws 2.4amp at 230v = 552w, so 552/746 would be a 0.75hp motor..
Does that mean it looses 2/3 of the total power?
I'm lost....

QldKev

 

[Ducatiboy stu]

Why not just use the standard 12v DC motor, and offer a small range of cheap, readily available belts and pullie's so we can choose whatever ratio for mill speed we need...

 

[pbrosnan]

At the moment I'm thinking of between a 400-500w motor to give an output of about 300-500 RPM with about 15-17Nm of torque...

That would give more speed and power to the mill, but I don't know how the mill would react to a faster crank speed... ie will the grain sail around the room? will the increased torque put strain on the mill if someone gets ambitious?

Hi John,

I run one of these http://secure.oatleyelectronics.com//produ...55423b51a509ac6 from Oatley as they didn't have the geared motors at the time. I run it flat out otherwise it chokes on the grain but once it's going the grain gets sucked in no problem at all. I hooked it up to a 24V power supply I bought on eBay. I've been using it for a couple of years and the crush is very good, no grain flying around the room.
Oh an the mill is driven directly via a very cheap spider coupling.

 

[motiondynamics]

What spec did the AC motor end up at? Why I ask is you mentioned 350-400w

Now I believe watts to hp = 746w to 1 hp

Looking at a sample motor is rated at 0.25hp (this is an old motor)
but draws 2.4amp at 230v = 552w, so 552/746 would be a 0.75hp motor..
Does that mean it looses 2/3 of the total power?
I'm lost....

QldKev

Hi QldKev,

Your formula works for DC circuits or for AC circuits like heaters and kettles that constantly use all the power they take. It doesn't work like this when you have anything inductive. Without getting too technical your motor doesn't use all the power it takes from the AC outlet. It basically gives a portion of the power back as unused energy as it rotates between cycles and a smaller portion is lost through efficiency forever and no, I have no idea where the lost energy goes. Space maybe?

The correct formula would be watts = voltage x amps x efficiency x power factor

Regarding the motor, I think the best choice for AC will be the 400w, I was thinking to change it to a direct shaft output from the motor for costs sake and supply just a pulley, but theres some people want the direct drive who have kids etc but I cant for the life of me find a cheap enough suitable coupler yet.

The DC is also proving to be a nightmare because the custom speed rates (100, 150, 200) are not common with high torque, so they are quoting me on building something new, which is cheap in big quantities but expensive in small runs.

So I can see why not many people have tackled this particular niche problem. The market is small and the costs high. Still, I hope to have something to show people soon, though I don't know what I'll ultimately do because it will always come down to the bottom line, ie how much I will have to invest vs how much I think will sell and what speeds are best to invest in.

If only it was simple.

 

[leiothrix]

The formula is just W = V *A * PF

Efficiency is irrelevant, as we are talking about power used. Power used vs power deliverd is a different story however.

Rob.