When A Gingerbeer Gets Bored At Work?

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jwsparkes

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Not wanting to steal any thunder at all from Wallace's fine job at making his own mill. I justed wanted to share my experience with my own design and (kindof) "home made" mill that I completed earlier this year...

Piccies first -> see attachments. My original badly formatted cad drawing is also attached. I did this 1 to 1 for the sheetie cut the hopper templates from. Fun to have an extended format printer at work. "What you printing there?.... Ohhhh nothing!". The final design is slightly different to the drawing, but I never had time to correct it. GoldStar brewery is the No. 1 brewery in The Hill, Newcastle. A mate of mine at work and a member on here.

Rollers are 2" dia 316 stainless steel, 150mm. Axles are 12mm dia, 15mm long. Drive shaft is 50mm long with 25mm long 120deg spaced flats for drill chuck.


The opposite side of the roller axles are drilled and tapped M8 25mm deep (for attachment of the drive gears)

Side plates are 10mm thick 7075-T6 aluminium plate. Milled to suit 12mm ID, 28mm OD 8mm thick sealed bearings (SKF 6001-2RSL) rated for 30k rpm and load rated to 2360N. Overkill, but funcational and practical. AU $8 each from any SFK distributor.

Side plates milled for bearings to achieve approx 1mm gap at rollers (I measured gap on assembled mill and it was between 0.9 and 1.1 as there is a slight taper left to right). The time and cost (and not being able to convince the machine shop for the extra time to make eccentrics) so I went with fixed gap. I brew in a bag so figured it would be ok.

The gears are 1.5m, 35 teeth spur gears (KSSA1.5-35) that I brought on line from a shop in NY (USA), http://qtcgears.com . It's a Japanese gear and is available in Aust. Closest distributor was in Melb, I asked for a quote $120 each, plus GST plus postage. Gears from US were US $17.39 each plus $US17.90 postage. This was in March, and the total cost as appeared on my CC was less that the US cost!

These gears have a 10mm plain hole for the hub, I used an off the shelf (aerospace) bush pressed into each gear to achieve an 8mm hole. Gears are attached to the outside of the mill assy using high strength (1000MPa UTS, 900MPa Yeild) 8mm bolts with plain washers and an 8mm nut (to clamp the gear to the bolt) using high strength loctite. The gear/bolt assy were then threaded into the rollers with high strength loctite.

Base board is 20mm thick construction plywood, sanded smooth and epoxy lacquered.

Hopper is 1.2mm thick 316 stainless, fastened with monel (nickel copper alloy) solid rivets. Screws for attachment of the hopper to the mill were scrounged from an old microwave. I stripped the old zinc plate and re-plated them and passivated with blue trivalent chromium (new standard over the nasty yellow hex chrome passivation).

So, the grand total of this project cost 4 x $8 for the bearings, $50 for the gears. Well, and a case of Coopers Pale ale for the machinist.

This was a "foreigner" job at work. Working at an aerospace facility has it's good parts. All the materials were "sourced" locally. One of our sheeties formed up and assembled the hopper, and one of our machinists kindly made the rollers and the side plates. The knurling on the rollers wasn't as deep or as coarse as I would have liked. I initially wasn't going to gear the rollers and was going to use my 850W hammer drill to drive the thing. Without the gears, the rollers spin very easily by hand (would free spin for a bit), but the rollers would not catch the grain very well. But when they did (after a frustrating 15mins) my drill would simply jam!

I went the gear option to ensure the grains were always pulled into the rollers first time. The big down side is that there is very light interference between the gears. I can still turn the rollers by hand easily, but they definitely down free spin.

To test the torque requirement, I filled the mill with barley and used my torque wrench on one of the gear bolts. I started at 10Nm and slowly wound it up until the mill turned and crushed the grains. That torque was about 25Nm.



My drill won't drive the mill, so I ended up welding up a dodgey handle. 12mm ID mild steel tube and I drilled an 8mm hole and welded on a 8mm nut for a "grub" screw. I use that to lock onto the flats of the drive shaft. For the handle end, I welded on a length of threads rod, and put a 10mm ID steel tube and put a nut on the end (with high strength loctite). The handle is not so swank, but it works. A good workout when crushing the grains.

I usually just sit the board over a 20L handy pail. But it's difficult to hold the thing steady and crank the handle. Think I need that kitchen stand from Bunnings.

Hope you all enjoy.


Hopper_1.JPG


Hopper_2.JPG


Hopper_3.JPG


Mill_Assy_1.JPG


Mill_Assy_2.JPG


Mill_Assy_3.JPG


Gears_1.JPG


Gears_2.JPG


Base_Board.JPG


Cranking_Handle.JPG


View attachment GSB_001_GoldStar_Brewery_Grain_Mill.pdf
 

Malted

Humdinger
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Yes no chance of grains getting caught in the gears, nice solution.
Champion mill.
 

_HOME_BREW_WALLACE_

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Not wanting to steal any thunder at all from Wallace's fine job at making his own mill.
:lol: funny......

Makes my small rollers look like a childrens toy Remember its not the size of the rollers, its how you use them :p

Seroiusly, nice work there, i love the gear placement, brilliant idea!

Quick question...... Where does the gingerbeer thing in the title fit in???
 

ledgenko

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Muddzy ... Ginger beer in my experience and always be seen in a Green skin too !!



Much respect from a

Scablifter ...
 
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