Homemade Ball Mill

[Barren Realms 007]

The drum for the ball mill I built is a discard from the oil and gas industry which I picked up at the scrap yard, the diameter is 16 inches and has a 3/8" inch wall thickness. The drum turns at 15 rpm, it take 2 hours to crush IC's into a fine powder. The motor used is 1/3 hp from an old blower motor running 3450 rpm

Using a motor that ran 1725 RPM would turn the drum half again slower than it does now,and would work but take twice the time to crush your IC's into powder.

The simplest form of ball mill drive would be to use a chain wrapped around the drum, welding a sprocket tooth every 3 or 4 inches, the end result would be a very large sprocket, and would also keep the weight down.

To align and space each tooth before welding use the chain for a pitch guide. You may have to cut the teeth from a sprocket but this is going to be far more economical for you than buying a sprocket that large.

For the motor end Browning makes semi finished blanks, both in gear and chain sprocket stock with an assortment of couplers and bushings, kind of an adults Mechano set

Belts may work, but remember a charged drum is going to be very heavy and belts have a tendency to slip, your best bet would be using a serpentine belt such as used on most automobiles of the last 20 or more years.

The first ball mill I built use a 5 HP DC motor directly coupled to the end of the drum, similar to what I have done with the latest mill. The beauty of the DC motor was that you could electronically control the RPM. I have one DC motor left that is going on my drill new drill press.

How many lbs of chips was in that batch that took 2 hrs?

The current motor you are using must have come out of a commercial blower. That 1750 RPM motor you could adjust the pully size. What kind of gear box was that on your's and do you know what it came off of?

 

[Anonymous]

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[pinman]

Would the balls from old computer mice be suitable in a small ball mill? 5 gallon capacity.

 

[4metals]

Considering how light a computer mouse is how much can the ball weigh? Your goal is to crush the material not caress it. Balls in a ball mill need to be heavy.

 

[Barren Realms 007]

You don't have to use balls. You can use steel bolts, pipe nipples with caps on them(you can pour lead in them to make them heavier).

 

[leavemealone]

Barren, I would not suggest pouring lead inside unless it is completly encased in grade 8 material.That includes making sure the nuts and bolts are grade 8 also.It was mentioned on another post about the softer metals also wearing down and you will be left with Fe contaminents.Grade 8 is hard enough where that shouldn't be a problem.

Gustavus,I am curious what you used to incinerate that much material at once.I use my kiln 2200F or my furnace 3000F but I can only run a few pounds at a time.
Johnny

 

[pinman]

You don't have to use balls. You can use steel bolts, pipe nipples with caps on them(you can pour lead in them to make them heavier).

Good to know I was under the impression they had to be made of a specific material. Thank you.

 

[pinman]

I was in the middleof posting when leavemealone mentioned grade 8 material. Is there a way to determine it's grade by sight?

 

[qst42know]

http://www.rockcrawler.com/techreports/fasteners/index.asp

 

[Barren Realms 007]

Barren, I would not suggest pouring lead inside unless it is completly encased in grade 8 material.That includes making sure the nuts and bolts are grade 8 also.It was mentioned on another post about the softer metals also wearing down and you will be left with Fe contaminents.Grade 8 is hard enough where that shouldn't be a problem.

Gustavus,I am curious what you used to incinerate that much material at once.I use my kiln 2200F or my furnace 3000F but I can only run a few pounds at a time.
Johnny

I agree Johnny but some might not have access to these types of metals. I have about 4-5 5 gal buckets of wheel studs that I can use. I have a lot of pipe I can cut and thread and cap to use, not the best item I agree but some have no other choice. I have hundreds of lbs of lead I need to use some where. One of these days I'm going to have to post some pictures of my shop.

 

[pinman]

http://www.rockcrawler.com/techreports/fasteners/index.asp

Good link thank you.

 

[leavemealone]

I agree Johnny but some might not have access to these types of metals.

Absolutely.If you (or anyone else) has no access or cannot afford grade 8 it's not that big of a deal.Simply make sure you check your material using a strong magnet.There are numerous methods for doing that here on the forum.
This entire forum is about accomplishing things with what we have available.In this case it's ok because the magnet will seperate the Fe.
I am fortunate enough to have access to pretty much anything here,and I tend to forget that when dealing with the members on the forums.Sorry about that.
Johnny

 

[Anonymous]

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[pinman]

I have 1/2" x 2" long grade8 bolts how many do I use Ina 5gallon mill?

 

[4metals]

The down side to using bolts is the ball mills that do not have dump doors and dust enclosures require you to dump the charge and the crushing media together. Then you have to clean the crushed powder off the media. I can imagine the threads becoming packed with crushed material and needing to be cleaned.

Time consuming, however use what you have, fill the mill half way with media.

 

[Anonymous]

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[Anonymous]

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[Barren Realms 007]

Man ya'll are tough on a guys ideas today :roll: .

I'm going to go put my dunce hat back on and sit in my corner.

 

[4metals]

Not true 007

If you have a ball mill with a dump door and a dust enclosure, you tumble the charge with whatever heavy medium you have then stop the mill, change the door to a dump door, which has holes in it, and run the mill. The dust falls out into a tray, the dust enclosure keeps all of the dust inside, and the media cleans itself. Now bolts will take longer than balls to self clean but it is do-able.

If you ball mill every day, multiple loads a dumping mill with a dust enclosure is the only way to go.

 

[Anonymous]

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