Motorising the mill

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Permalink Reply by James P on July 13, 2009 at 12:44pm

To be honest crabbey I have no idea... all the literature I can find has mills running at 150 ish. Northern Brewer say just run it at 500rpm on their website. I should experience to see what the crush is like, and check it's not ripping the husks then.

Looks like I will have to get a 3/8ths to 1/2 inch bushing if I want to use pulleys....

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Permalink Reply by Horace on July 13, 2009 at 6:51pm

I ran mine off a variable speed drill for a while - worked alright just holding the drill also had it set up with saddle clamps holding the drill. That was OK but awkward plugging and unplugging the drill for start/ stop.

Now have electric motor driving it with pulleys. 3/8" - 1/2" bushing works well. Just clean well and use Loctite. Leave to set for the required time. Will hold very well for rotational force without the need for grub screws.

TradeZone is a great place to go for that sort of thing. Atleast up here.

These are the guys in CHCH:
TradeZone
George Henry & Co
47 Manchester Street
ph 03 366 5186
www.georgehenry.co.nz

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Permalink Reply by James P on July 13, 2009 at 7:06pm

Cheers Horace, I'll take a look at george henry.

Alternatively I was going to look at an assembly to push the trigger in slowly via a wheel to achieve gradual speed increases. I'm no engineer though, so I can see that going pear shaped really early! :)

(Best to stick to the tried and true methods.)

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Permalink Reply by Steve Baker on July 29, 2009 at 1:50pm

I'm thinking of doing this too. These guys have the pulleys, now I need to get some bush:
http://www.johnbrooks.co.nz/?action=products&type1=V%20Belts/Pu...

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Permalink Reply by Nick T on August 17, 2009 at 10:33am

If anyone is still doing this, I have just been to John Brooks here in Chch, two pulleys at 1:8 ratio (12 inch and a 1.5 inch) was about $130 ish.(I need to reduce down from 1400 RPM, Monster recommend 150 - 250 RPM). If you have a slower motor to start with then your costs should be quite a bit less as you won't need sucha 'monster' pulley. I have just dropped the larger pulley off at a machine shop in Sockburn that was recommended to me, to get a sleeve put in it (half inch bores are the smallest you can get for pulleys it seems) and redrilled for the grub screw, will let you know what that costs. Second hand pulleys do not seem to be a big feature item on Trademe!

In retrospect, should have purchased the half inch shaft for the mill, didn't realise the significance of this until it was here. No need for a sleeve, and not the same risk of the shaft either bending under the weight of the large pulley, or being over-torqued!

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Permalink Reply by Steve Baker on August 17, 2009 at 1:05pm

I'm still tinkering away. I've scored a free dryer and am currently trying to resurrect the 1/6hp motor inside it. The motor has a 1/2" shaft.

I'm thinking of getting these pulleys:
http://blmarshall.co.nz/shop.php/-general-hardware/aluminium-v-pull...

What kind of bore do your pulleys have? I called John Brooks and they seemed to imply that they were tapered.

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Permalink Reply by Nick T on August 18, 2009 at 9:37am

Hi Steve, they are straight bores, with a grub screw through them to tighten down onto the shaft. From my reading of the Monster Mill page, you will need a capacitior start motor of at least 1/4 HP (I got a secondhand 1 HP motor, although I was looking for 0.5 - 0.75HP at the time). http://www.monsterbrewinghardware.com/faq.html#q6 The pulleys on the blmashall page seem to come in packs of 10, and only up to 6 inch? I guess if your motor is running at about 800 - 1000rpm then you will be OK on this count.

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Permalink Reply by Steve Baker on August 18, 2009 at 1:14pm

I thought the packs of 10 were only for delivery of stock to hardware stores - I could have misinterpreted it though.

I'm aiming for a 1:3 ratio to bring the rpm down to 475rpm. Apparently the Barley Crusher Malt Mill will run at 500rpm. So a 2" and 6" pulley should do it.

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