635 replies to this topic

[seymour]

Quote from Passfire: "Lift bars will substantially increase the efficiency of your ball milling jar. The purpose of lift bars is to prevent the media from sliding on the bottom of the jar as it rotates. This sliding action reduces the amount of tumbling that takes place, thus reducing the grinding action. The amount of slipping taking place during milling can actually be detected by sound. The idea sound of a well tuned jar is a constant clacking of milling media. Repeated patterns of clacking followed by silence is an indicator of slippage. Constant silence would be 100% slippage. "



Seymour.

[Andrew]

probably, but anyway (edit----> that's a probably to the "probably been asked before" question, NOT seymour's explanation). the problem is that your mill is not rotating fast enough. Well it's not really a problem, all that will happen is that the milling process will happen less efficiently and slower. It'll still work, there is a formula on the forum for the optimum milling speed.

To make your mill more efficient you could;

use different sized milling media,

use a different size milling jar,

make your mill turn faster.

Did you buy a tumbler? because they are not designed to mill, they are designed to polish. Anyway, a rough guide is, when your mill has no material in, just media, at it's optimum speed it will be making the most noise. Our 15L mill is noisy enough to hurt your ears, and that is running too slow, in operation it does the same "picking up and dumping", now we have a lathe we can make the mill to spec. My 3L bp mill is optimum (almost, it might turn a little quick), and it is bloody noisy to start with. Once milling is near completion, it is silent.

Is the speed a real issue??? Well one mill that is not efficient, does the same yours does, mills bp in 3-5hours from fine-ish materials. My pseudo optimum mill mills bp in 1-2hours from 5-10# (coarse) material. Halving the time it takes to mill is a nice thing, but not essential, your mill will do it's job, but it could do it quicker.


edit ---> don't mean "probably, but anyway" to seymour, I mean it to the "probably been asked before" question by 1145climber. You got your answer in before mine, and now it looks a bit silly, sorry!

Edited by Andrew, 08 June 2005 - 08:48 AM.

[seymour]

Lol, confused me at first, but My damaged self esteem will recover.

[KC Blast]

Hey everyone. I was curious to know if $60.00 is a good price for a 6lb ball mill (rock tumbler)? I can't see the manufactures name, but it has a red body and two 3lb tumblers. 120v 60 Hz and is fan cooled. Does this seem like a good price or can I do better? Thank you all!

[Mumbles]

The manufacturer is Chicago Electric power tools, and that price isn't bad. It is about $40 here in the states. I swear I saw it for $30 on sale once though. I don't know what kind of availability or normal price there is in the UK. Shipping it to the UK would be bad, and you'd probably be better off getting that one.

[LadyKate]

Hey everyone.  I was curious to know if $60.00 is a good price for a 6lb ball mill (rock tumbler)?  I can't see the manufactures name, but it has a red body and two 3lb tumblers.  120v 60 Hz and is fan cooled.  Does this seem like a good price or can I do better?  Thank you all!

 

$60 is too much. Check eBay out - they go for $49 normally in the Harbor Freight store (harborfreight.com) and they are on sale for as low as $29 on occasion. They are not truly 6 pound machines and they will fail if you load them that high - the belts will heat and pop. I load mine with one 2.8 pound drum and it runs day and night with no problem. If I put two drums on it, it will die in a couple of days. I get replacement belts from the hardware store - 4" O-rings (1/8" wide).

[KC Blast]

Thank you for the replies. The one I saw was on ebay, but shipping was almost half of the asking price. I too live in the states (KS) so overseas shipping isn't a factor. I'll look at harbor frieght when I get home from work tonight. Thank you everyone. Oh, one more question, do I really need a 6lb one, or do most of you suffice on 3lb? THank you

[LadyKate]

Oh, one more question, do I really need a 6lb one, or do most of you suffice on 3lb?  THank you

 

Buy two 3 lb ones (if you can find them on sale, they will be cheaper than the 6 lb one). In either case, only load the jars to about 2.5 lbs maximum (less if you can wait longer for the mill to be effective).

If you have a good deal on the 6lb one, then go for it. It is always nice to have two jars.

[JamesH]

Here's a ball mill I built about 5 years ago and I'm glad to say it's still going strong. The milling jars are constructed from sections of 4" PVC pipe with screw-on end caps. It's driven by a motor/reduction gearbox unit.
I use lead milling media, but am intending to convert to brass. I find that soft lead tends to flake on the surface contaminating a composition. This can be seen when milling a white substance like KNO3 - it takes on a grey colour. I doubt this is of any major consequence however.

Heres a photo: -
http://i11.photobuck...22/Ballmill.jpg

[KC Blast]

How much media do I need to fill 2 - 3lb mills of lead or copper media? Also is copper better than lead or is it just as well to stay with lead due to price/availiabilty? I'm just starting out in milling, buying my mill tomorrow actually since I found out that I have a harbor freight store 15 minutes from me! Any particular place I should go for the media here in the states? I know united nuclear sells it 100 pc for $25, I didn't know how much that would cover though. Thank you all. I've learned so much in the past few months reading and trying to follow everyone's tips and ideas. I'm not in any rush to become a great show master, just having some fun in my spare time making fountains, gerbs, pin wheels. Since I live in a fairly quite community I want to keep it that way. Maybe I'll try my hand at some bp rockets that don't explode just to see if I can. Again, thank you all and take care!

Eddie

[Mumbles]

You need 100 to 150 .5" lead shot to properly charge a 3lb barrel. I tend to slightly underfill so I can fit more comp in them. $10 per 100 is very common. Check gun reloading shops for .5" shot. It can be found on the internet as well.

Copper can be cheaper depending on your source of lead. It is more work however. To me, and this is just my personal opinion, it is better to start out with lead shot to get used to things. After you have got a good grasp on milling and want another larger mill, then I recomend to move up to copper filled lead. When I make my new mill, I am thinking I will probably get lead shot again. When that wears out, I will get brass rod. It costs about $80 per jar for properly charging it, but it will NEVER wear out. All that must be done is cutting it, which is done with an electric saw. Brass rod may not be dense enough for smaller mills.

[chris17]

I finished my new mill a few days ago. I had to build an all new one because I coulnd't stand my old crappy mill.

[Djsethall]

I have found a link for anyone in the US wanting steel media. It is an Ebay Store. I was wondering if the efficiency could be increased by using different size balls? Anywho here is the Link http://stores.ebay.c...aderLinksQQtZkm?

[Mumbles]

I have been looking at various materials for media. I was wondering if there were any grades of stainless steel that are better than others. Of course sparking is my #1 concern, but lack of corrosion is also important. I have found a good supplier for 303, 304, 416, and 440.

[Djsethall]

I have just researched brass balls for media. For those with safety in mind. There is a place here in the states that sells 1/2" brass balls for $0.63 a peice if you buy 100 of them. That puts media at about $63.00. If anyone can find a better deal please let me know.