Motor For Millmaster Input

[samhighley]

BUT, I am sure I can crush that amount of grain with by hand [and with big arms] almost as fast with the handle.
Wimps.

And i'm sure I could ride my pushbike down to the HBS and carry the grain home on my back, but it doesn't mean i'm going to

 

[Pumpy]

Sammy , That is very inspiring piece of work .

You havent mentioned the electrical work , was it a big job any additional components ?

is it straightforward to wire this unit ?

Pumpy

 

[samhighley]

I noticed that you had a bit of chain whip which can cause a bit of noise

Yeah, there is a bit of chain noise. I'm wondering if more chain tension will solve that. The platform that the motor sits on is adjustable up and down via a couple of bolts that hold the platform down, so I might add a bit more tension. Failing that, i'll look into chain tensioners such as the one suggested.

 

[samhighley]

You havent mentioned the electrical work , was it a big job any additional components ?

The electrical was the simple part really. It's just two 7.2 amp hour sealed lead acids from Jaycar @ $29.95 each, which should give at least fourty minutes of crushing time based on the previously mentioned current draw of 10 amps.

I will likely look into a power supply at some point in the future, as forgetting to charge the batteries would make a crappy start to a brew day. I'd like to get a good current draw reading first though, and neither of my multimeters are capable of doing the job. Would it draw more or less current at 24 volt opposed to 12 volt, as the earlier mentioned current reading (AndrewQLD?) was based on 12v.

 

[Sully]

Very very nice, chain drive...........Now don't get me wrong, it's nice and power driven, BUT, I am sure I can crush that amount of grain with by hand [and with big arms] almost as fast with the handle.
Wimps.

And i'm sure I could ride my pushbike down to the HBS and carry the grain home on my back, but it doesn't mean i'm going to

besides it isnt as cool... as well as MORE POWER!!! <insert Tim Taylor grunt>


Top notch job Sammy. :super:

 

[samhighley]

This is how I solved the problem of grain entering the synchronising gears of the mill:



I took a piece of pine and drilled two holes using a hole-saw the same diameter as the mill rollers. I then trimmed it up with the drop saw until it fit nice and snug:



It was then mounted to a piece of aluminium. The fit is nice and tight, and the pine actually rubs on the rollers a little bit, but I figure this will soon go away



I think a critical factor in any gear guard design is to make sure that if for some reason the guard becomes dislodged, it cannot jam the rollers.

 

[atkinsonr]

Would it draw more or less current at 24 volt opposed to 12 volt, as the earlier mentioned current reading (AndrewQLD?) was based on 12v.

Hi Sammy.
While there are other variables, I think you can get a pretty good approximation using the power equation, P = IV.

Basically, let's assume you are drawing 10A (I expect at 24V you are drawing less than this, you'll need to measure it to see).

P = IV
P = 10A x 24V = 240 Watts

So to generate the same power at 12V

P = IV ... so...

P / V = I

240W / 12V = 20A

Depending on how much load your mill is putting on the motor, I expect your actual values will be less.
Also, have you measured the voltage? It's possible that your batteries aren't exactly producing 2 x 12V.
Finally, managing the chain tension as Rob suggested will improve the efficiency of the system a little by smoothing out the peak loads (Current spikes).

I'm in awe of your carpentry!

Hope this helps!

Richy

 

[porky]

Would it draw more or less current at 24 volt opposed to 12 volt, as the earlier mentioned current reading (AndrewQLD?) was based on 12v.

Mate,
It will draw half the current (amps) with 24 volt instead of 12 volt.
volts X amps = watts

Very nice job on the whole set-up.
Well done. I wouldn't be too worried about the chain wobble on the no load side. Won't hurt anything, unless it is too noisy for you.

Cheers,
Bud

 

[samhighley]

It will draw half the current (amps) with 24 volt instead of 12 volt.

Sweet, well that means i'll get over an hour of constant milling time

 

[samhighley]

For anyone interested, here is the template I made for making the motor mounting plate:

View attachment Oatley_motor_mount.pdf

 

[samhighley]

I filled the hopper right to the top the other day for a Strong Scotch Ale, which was about 10kg of grain in the hopper.

Started up fine and crushed the whole lot without skipping a beat.

Glorious.

I now realise that my output bin is a little small, so sometime in the future i'll likely make it bigger.

 

[Back Yard Brewer]

Yeah, there is a bit of chain noise. I'm wondering if more chain tension will solve that. The platform that the motor sits on is adjustable up and down via a couple of bolts that hold the platform down, so I might add a bit more tension. Failing that, i'll look into chain tensioners such as the one suggested.

Currently exploring various options to drive my millmaster.

Would a V belt system be a better course of action instead of a chain? If there was a foriegn object in the grain at least the belt might slip for safety and not drag through something that could not be crushed.

BYB

 

[samhighley]

Would a V belt system be a better course of action instead of a chain? If there was a foriegn object in the grain at least the belt might slip for safety and not drag through something that could not be crushed.

I discussed this with my engineer, and he pointed out that the motor will stall long before it pulls something solid through the rollers.

 

[spog]

I'm running at 24 volt via two lead-acid batteries hooked up in series. The large gear is 40 teeth and the small is 10 for a 4 to 1 reduction, which means the mill is running at around 80 rpm. As the video demonstrates there is more than enough torque to handle the crush.

I had the 40 tooth sprocket custom machined down to the shaft size of 12mm. Mashmaster should seriously consider making the mill shaft a half inch (12.7mm). This would make it a lot cheaper to motorise.

sammy,can you tell me where you got the chain sprocket from,i have a mashmaster too and am trying to motorize it,your set up looks the go.
i guess i could get a sprocket with a smaller diameter centre then have it machined out to 12mm to suit the mashmaster...cheers..spog.....

 

[spog]

sammy,can you tell me where you got the chain sprocket from,i have a mashmaster too and am trying to motorize it,your set up looks the go.
i guess i could get a sprocket with a smaller diameter centre then have it machined out to 12mm to suit the mashmaster...cheers..spog.....

ahh i forgot the most important part,with the mashmaster having a 4mm keyway how have you fixed the chain sprocket in position.....cheers....again.spog......

 

[BennyBrewster]

Looking at the makes me wanna back my dirtbike up to the mill hook the chain up and see what 60hp can do to grain husks.

 

[samhighley]

ahh i forgot the most important part,with the mashmaster having a 4mm keyway how have you fixed the chain sprocket in position.....cheers....again.spog......

I had the sprocket custom machined. They also added the 4mm keyway.

 

[Greg Lawrence]

Hey Sammy
I dont think that those batterys are going to last too long if you run the mill for a long period of time.
I use those 12VDC 7A/Hr batterys at work for backup on power failure to 12VDC security equipment. They are designed more to deliver a small current for a long period. Eg, 1A for 5 Hrs. Although they are 7A/Hr, voltage drops too low after about 5 hours).
IMHO, you would be better off using a car battery which is designed to deliver high current.
Feel the batterys after your next crush. If they are getting hot, you are going to have problems.

Gregor

 

[mash head]

sammy,can you tell me where you got the chain sprocket from,i have a mashmaster too and am trying to motorize it,your set up looks the go.
i guess i could get a sprocket with a smaller diameter centre then have it machined out to 12mm to suit the mashmaster...cheers..spog.....

For such things I would look to chains & accessories in torrensville. They sell a wide range of transmission chain ,sprockets and key way steel. I would be very supprised if they couldnt help. Happy engineering
Cheers Greg

 

[samhighley]

I'd be surprised if they can help with a stock item.

The Millmaster has a 12mm shaft, which is *very* odd.