Question on Ball Mills

[no_fear]

I've been looking for a way to make a good ball mill. I found another topic from I think around April 2002 that talked about it, but I had 1 question that wasn't answered.

I used to be into geology type-stuff a little bit ago and I bought a rock tumbler. This little machine is used to take round jagged rocks and make them smooth and polished. Does anyone know if these make good ball mills at all?

So far, after looking at the ball mill stuff that I found, the only problem I see with it is that it is VERY small. If you guys do think that it would work, I might have to think about buying a bigger one.

Just a few little things that might help you guys help me.... the box says that it is run off of .15 Amps, 10 Watts, or 60 Hz. I know that isn't much at all, but do you think it would be enough to make some small batches of Al powder?

[Bert]

The larger the diameter of the milling jar, the faster a ball mill works. I converted my hobby rock tumbler to a ball mill when I was 16 or so. I used .32 cal. lead balls for media, and made workable BP. The milling time needed was long- a couple of days with the 4" Dia. milling jar, and the motor needed a push to get it going due to the great weight of the media. Capacity was perhaps a cup volume of the material being ground. If I'd known then what I know now, I would have used nickels for milling media instead of lead balls.

Using steel ball bearings and Al foil to produce pyro grade Al will work, but it's going to take weeks, not hours with a small tumbler. Search on the topic... There is plenty of information relating jar size, jar fill and rotational speed of optimum setups on the net. Remember that you need to frequently open the jar to allow the fresh Al surfaces to oxidize and/or use a coating such as oil or stearine, or you may have a metal dust fire on your hands.

I currently own a 12lb. rated tumbler with a jar 7 1/2" in Dia. This is used with Coors cylindrical ceramic media if I need a small batch of chems ground. It works several times as fast as my childhood rock tumbler, well worth the investment. http://tinyurl.com/yy4url

(edit)
The prices in that link are nearly twice what I paid for my tumbler. Look around, I can't remember the seller's name right now.

[tmp]

Bert, are you using a Lortone ? My tumbler is a Lortone FD-12 and is about
optimum for the money. On one rock shop page it's selling for $155. Moving
up to the 20 LB model wouldn't be cost effective at $580. Before I bought
the Lortone, I made my 1st Al powder using this bullet casing cleaner. It
works well but because it's a "vibrating" type device it's noisy as hell ! I can
barely hear the Lortone when it's running. The only real maintenance I've
needed for the FD-12 is to keep it dust free and occasionally put a dab of
motor oil on the roller bearings. Well worth the money IMHO !

No_Fear, it sounds like you have a 3 or 4 LB model and Bert's correct in
stating that it'll take a very long time to mill. I just saw a QT-66 on eBay
but there is no "Buy It Now" price. The link below will direct you to where I
bought my tumbler.

http://www.jaderockshop.com

[Bert]

Yes, it's a Lortone 12 lb. unit. I bought it about 6 or 7years ago, it was only about $90.00 for the unit and $30.00 for a spare 12 lb. drum at that time.

[no_fear]

Tmp, you are probably right. I'm not even sure if it is even that size. My tumbler isn't anything like the ones that you guys have. It does the same thing, but its actually more of like a toy version. I was just wondering if a rock tumbler would work as a ball mill. And obviously you guys answered my question. As for buying a bigger 12 or 20 pound tumbler, theres a rock shop about 15 minutes or so from me that I could check.

Thanks for your help guys. I can definitely get something figured out with this now.

[stupid939]

If you are thinking about making small batches (maybe 100-200g) of aluminum powder, I may have the thing for you. I originally bought it for black powder, but I bought some Chrome steel spheres and started milling my machine scraps and coarse aluminum powder.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=46376

It is only 3 lbs. but it works fine for me. I bought 150 1/2" chrome steel balls from a guy on ebay, and as we speak, I am milling some older coarse aluminum powder. Last week I did a batch with shavings and powder, and It worked great. It took about a week to get powder fine enough for a salute, but it gets the job done. If you search, they also have a dual drum tumbler.

They have stores all over the country, so you may not even need to pay a shipping charge.

[no_fear]

Yeah. There's actually a Harbor Freight store in town here. My grandpa pretty much lives at the store and buys me anything that he thinks I might need and that is on sale there. It's a bit of a drive from where I live, and the geology store I mentioned is closer, so I think I might try it first. If I get a chance though, I'll go look.

And you said about 100-200g batches... I'm not sure how much I would actually need, but I just need enough to experiment with a little.

[Cobalt.45]

The Harbor Freight "Chicago Electric" mill (tumbler?) does work real well, especially for the price.

Plan on going through belts rapidly, especially if you run it at full capacity.

I've taken to using black nitrile O-rings as belts. They outlast the supplied belts 4:1 at least, and cost pennies.

[no_fear]

Alright thanks guys. You were tons of help.

One last question though. Would it be more cost efficient to follow the plans on this site (http://www.wfvisser.dds.nl/EN/ballmill_EN.html) or to just buy one from one of the places you guys mentioned? And would one of them be easier to replace/repair than the other (between homemade and store bought)?

[Bert]

A small ready made one is a quick fix. A home made one will likely cost you nearly as much, or even more if you don't have the materials in your junk collection allready. The plus side, you can make it to the dimensions and spec's you choose. Also, as you note, anything you build you should be able to fix.

If you make your own, remember that LARGER DIAMETER is preferable to GREATER LENGTH in regards to speed of milling. Large diameter PVC fittings become rather expensive, and pipe is usually sold in minimum standard lengths so you'll be forced to buy more pipe than you need for a single jar.

Price it out from your suppliers, and decide how quickly you need how much output.

[jpsmith123]

Bert,

I'm wondering, where did you get the coors ceramic (alumina?) milling media you mentioned? Did you get it from the same place you linked to in this thread?

I just got a lortone FD-66, so now I'm looking for an inexpensive source of ceramic media for it.

Also, how many lbs. of it do you use in your Lortone 12 lb. barrel? Thanks.

[Bert]

A quick check of ebay shows several suppliers. This one is selling 10 lb. lots of the type I have for $16.00 + shiping. http://tinyurl.com/2dt7ab

I use enough to fill the mill jar 1/2 full. I don't know the precise weight right off the top of my head- 10 lb. is about a large coffee can nearly full.

[jpsmith123]

Thanks for the info. BTW, did you modify your Lortone tumbler to make the barrel rotate faster, or did you leave it alone?

[Bert]

I left it as it came.

[Spiffy]

Thanks for all the info about the ball mills, I am considering purchasing a model similar to the one Stupid939 linked. I am just testing it out, as I am new to this. On the topic of grinding media, how many ball bearings would you need per batch? I see that you can buy both Chrome Steel and Lead/Antimony balls, and I understand the pros and cons of both, but do I need 100? How quickly do they wear down, or become otherwise unusable?

[Bacon46]

I built a ball mill that has worked well out of junk I had laying around.
If you don’t have piles of mostly useless stuff lying around like I do, you can get all of the material, with the exception of the motor, at you local hardware store.

The wiper motor you can get at an auto salvage yard or at All Electronics (http://www.allelectronics.com/cgi-bin/item/DCM-249/400400/POWERFUL_WINDSHIELD_WIPER_MOTOR_.html)for $16.75 plus shipping. It’s not the same motor that I used but any wiper motor or low RPM gear motor will do. You can probably get a transformer at All Electronics as well.

Material used:

1. 12” of 4” I.D. ABS pipe (Black Sewer Pipe)

2. 1 – 4” ABS Slip/Thread Coupler

3. 1 – 4” ABS Threaded Plug

4. A piece of plastic or other non-metallic material cut to fit snuggly inside the pipe. This should be something that is easy to clean and does not absorb water or other liquids. I used ¼” thick ABS taken from a 4’ x 8’ sheet. Any plastic that you can glue or otherwise attach to ABS will work.

5. 1 – 4” ABS Pipe Cap

6. A windshield wiper motor out of a 1998 Saturn. Any low RPM gear motor will do.

7. 12vdc / 800 watt transformer from a low voltage light. Only needed if you are using a DC motor. Voltage and amperage required will vary depending on the motor used.

8. A 16” x 16” piece of ¾” plywood.

9. One pair of drawer slide wheels to support the end of the drum not attached to the motor.

10. One switch and some miscellaneous wire and connectors.

11. Metal strap to secure the motor. Large hose clamps or “Plumbers Tape” work well.

Items 1 through 4 make up the drum.

Item 5 (The Pipe Cap) attaches to the motor.

One end of the drum slips in and out of the pipe cap. The other end rests on the drawer slide wheels.

If you want more capacity you could use a larger diameter pipe.

I use ¾” I.D. tubes filled with Bismuth rather than balls, so I guess mine would be considered a “Rod Mill”. The tubes are Copper, Aluminum or Steel depending on the application.

Use the links below to view drawings and images. The 3D model takes a miniute to download. It's in a slideshow format.

3D Model (http://img235.imageshack.us/slideshow/player.php?id=img235/2682/1173630264g0m.smil)

Rod Mill Exploded View (http://img339.imageshack.us/img339/5265/BallMillExploded.jpg)

Rod Mill Section (http://img339.imageshack.us/img339/8086/BallMillSectionJPG.jpg)

[knowledgehungry]

I liked the 3d images. I am curious how you connected the pipe cap to the motor. Looking at the motor in the link gives some help(the window wiper motor appears to come with a gear box) but I was wondering whether you used epoxy or what(I am ssuming that you drilled a hole through it to recieve the shaft).

I was going to make a ball mill of my own since my interests have been shifting more towards pyrotechnics as opposed to HE's lately, but instead of making my own plans I might just modify yours because I like the design so much!

EDIT: After watching the slideshow again I saw how you connected it, you drilled a hole through the cap and since the shaft was already threaded you put a nut and washer on to connect it. I would loctite it (the red kind that doesn't come off) so that the bolt doesn't get loosened during rotation, you may have thought of that already, or you may have the motor going counterclockwise having a tightening effect rather than a loosening one.

[Bacon46]

I created a couple of more images that show the connection between the cap and the motor. One is a monochromatic “X-Ray” looking inside the cap. The other is a view from the Top/Back in monochrome.

The hole in the center is providing clearance for the shaft and the nut that hold the arm to the shaft. The cap is actually bolted to the arm.

The only trouble I have had with this design is the bolt holding the cap to the arm has come loose once.

There is probably a better way to make this connection. This just seemed like a good idea at the time. Let me know If you come up with a better method.

X-Ray View (http://img490.imageshack.us/img490/520/capconnectionxrayrp7.jpg)

Top/Back View (http://img490.imageshack.us/img490/688/capconnectionmonochromeuq4.jpg)

[knowledgehungry]

I think your method is great. If you do not need to remove the cap all you need is to put some loctite threadlocker Red on the threads of the bolt, the bolts will never come off(without high heat and power tools). If you want to take the bolts off in the future for any reason you can try using the blue loctite threadlocker as it does a great job holding bolts from loosening but it is possible to undo them, I use it on almost every bolt on my motorcycle that I take off.

If you don't have access to loctite(you are non-US) you could use an epoxy on the threads. Loctite will be sold at Wal-mart, Home Depot etc. in the plumbing or automotive section most likely.

Once again very nice images.

[cracker]

I purchased some Chrome 1/2" media from this company and was very pleased with the price, 500 balls for $21.00. http://www.craigballsales.com/index.cfm?fuseaction=catalog.prodInfo&productID=179 (http://www.craigballsales.com/index.cfm?fuseaction=catalog.prodInfo&productID=154&catagoryID=179)

I also bought some of their 27/32" balls for the extra benefit of the different media sizes.

At that price it sure as hell beats out United Nuclear's prices ($50 for 100) and was also better than any Ebay deal I saw for Chrome 1/2".

500 turned out to be more than I needed, however the leftovers will make nice projectiles. :D

Needless to say this is a win-win situation.

[nbk2000]

Everyone with a clothes drying machine has a large capacity tumbler. ;)

Make a holder for your 5 gallon media drum, set it for air-dry only (no heat), and tumble in 1 hour increments. :)

[chemdude1999]

Everyone with a clothes drying machine has a large capacity tumbler. ;)

"Honey, what the is that racket from the laundry room?"

"Ummm, I'm drying my shoes ... That's it ... shoes." :p

[Frunk]

Everyone with a clothes drying machine has a large capacity tumbler. ;)


You can also buy an old junk dryer. As long as it works, it's enough, nobody cares if the controls are working except on/off. Open it, disconnect the heating elements, put sheet metal inside the barrel and you have a huge tumbling barrel.

It just has a ridiculous volume and torque. If it's too big, it's always possible to use the motor only.

[Bert]

I have seen several people modify small concrete mixers into ball mills.

[chemdude1999]

I have seen several people modify small concrete mixers into ball mills.

Actually these would be easier to modify, being that the components are not covered in sheet metal. Also, the one that I have used is variable speed, which can come in handy. The construction is designed for the weight as well.

[Bert]

Yes. They don't work half bad for industrial sized star rollers either.

[chemdude1999]

I was looking in Harbor Freight today and they have several sizes available at all the price ranges. It depends on how much you want to do. You could almost make a small commercial ball mill out of the largest one. I'm not sure how big the industries use.

[jpsmith123]

I recently bought a Lortone FD-66, as shown on the following linked page:

http://www.informulation.on.ca/A55770/cts.nsf/(AllByID)/A73D7645328C1AAC86256F62000A5C7C!OpenDocument

As it comes without a motor, I'm looking around for a motor for it right now. I'll probably end up buying the 1/3 HP NEMA 48 frame motor that Harbor Freight sells for $49.95.

I understand that Lortone doesn't make these (or the FD-12) anymore, but in case anyone is interested, some dealers such as "Kingsley North" apparently still have them in stock.

Anyway, the FD-66 comes with a drive pulley of 1.5" diameter, and the "load" pulley is 7"; given the diameter of the shaft and the barrel (about 0.75" and 7.5" respectively), the barrel rotates at around 37 rpm. Instead of the standard pulleys, I plan to use 2" and 5" diameter pulleys, to increase the rotational speed to about 70 RPM.