53 replies to this topic

[Zinginex]

Hey, i really am wanting to make a ball mill some time soon as the mortar and pestle just don't cut it. I have read up ALOT on ball mills and bearings and how they work but i'm 15 and i'm without bearings, or a motor. I'm pretty sure i'll find a good enough motor some time soon, when my mums washing machine breaks or something but i'm still left with the deal of having to make the rollers roll .

Theres a design where you secure the motor in place on one side of a wooden board and then on the other side you secure either rollers or castor wheels and then attach a belt, from the motor, around the milling jar, which is on the rollers/wheels. Turn the motor on and there you go the motor turns the belt, which turns the jar, which is on the wheels. Pretty simple. I think I'm capable of making that once i find a motor but i was hoping someone here would actualy tell me how hard it is to make a ball mill that rolls with bearings and somehow you connect the motor and cogs to the rollers

I've read up on bearings and i know about ball bearings and roller bearings and such but i have no idea how all you guys ,with ball mills out there, have got a roller inside the bearings. Have you bought like a set which has bearings and the right size roller/metal rod that fits inside the bearings? Where do you buy these "sets"? Do they come with their own perfect sized clamps? Is it just the right fit so once you've hammered the roller in it sticks there? How do you then connect cogs onto these rollers so the belt attaches to them and it drives the rollers? I am really hoping to be able to make one as i'm sure i will find it fun, as i enjoy the pride of homemade devices and making it itself, but i just need quite a bit of advice to start.
Thankyou

[Arthur Brown]

Maplin do bearings RS do bearings (//rswww.com ) Fenner do bearings http://www.fptgroup....ub_products.asp

Google the web for rock tumbler they are low duty ball mills but come at low prices.

Search Cooperman on here

[cooperman435]

Someone say my name?....................

Zinginex its honestly not as hard to construct a mill as you seem to believe. I honestly think your setup where the jar is turned directly by the belt is flawed mainly by the amount of traction you will need to rotate the jar, with 1/2 a container of lead media then bp as well you will struggle to make the belt not slip.

Ive unfortunately run out of the rollers I had in stock so cant offer you some myself but Im trying to find some more so will post if I do.

Ive come up with 2 main designs I use myself, the first is a direct drive unit where the jar has a screw thread protruding from the rear of the jar that engages into the motor output which is already geared to the correct rpm. Its the simplest design and the one most suited to smaller aplications.

The second design is a more standard design with two static rollers Ie simply a rubber roller that is attatched to a solid steel core these sit in bearings that are mounted to the base so the rollers turn in them freely, then the motor is mounted transversly to them (rather than in line like the first design) and the pulley ratios are worked out from the size of the jar (and its desired rp) the size of the rollers and the speed of the motor.

Its honestly not as complicated as that sounds basically make the machine with some adjustability as to where the motor is mounted then work out the pulley sizes.

I can hapilly make you some pulleys on the lathe but you will have to discuss with me the finer details to do the maths.

If you email me from my webpage you can also have a look at both designs as there are puctures of them both in use.

[Zinginex]

Someone say my name?....................

Zinginex its honestly not as hard to construct a mill as you seem to believe. I honestly think your setup where the jar is turned directly by the belt is flawed mainly by the amount of traction you will need to rotate the jar, with 1/2 a container of lead media then bp as well you will struggle to make the belt not slip.

Ive unfortunately run out of the rollers I had in stock so cant offer you some myself but Im trying to find some more so will post if I do.

Ive come up with 2 main designs I use myself, the first is a direct drive unit where the jar has a screw thread protruding from the rear of the jar that engages into the motor output which is already geared to the correct rpm. Its the simplest design and the one most suited to smaller aplications.

The second design is a more standard design with two static rollers Ie simply a rubber roller that is attatched to a solid steel core these sit in bearings that are mounted to the base so the rollers turn in them freely, then the motor is mounted transversly to them (rather than in line like the first design) and the pulley ratios are worked out from the size of the jar (and its desired rp) the size of the rollers and the speed of the motor.

Its honestly not as complicated as that sounds basically make the machine with some adjustability as to where the motor is mounted then work out the pulley sizes.

I can hapilly make you some pulleys on the lathe but you will have to discuss with me the finer details to do the maths.

If you email me from my webpage you can also have a look at both designs as there are puctures of them both in use.

Thanks for the detailed reply but i've done a lot of reading up and i don't mean this rudely, i am grateful for your reply, but i know how to make a ball mill it's just --> standard design with two static rollers Ie simply a rubber roller that is attatched to a solid steel core these sit in bearings that are mounted to the base so the rollers turn in them freely, then the motor is mounted transversly to them (rather than in line like the first design) and the pulley ratios are worked out from the size of the jar (and its desired rp) the size of the rollers and the speed of the motor.

That to me is not simple lol. I don't have a clue where i could find the right size clamps to clamp the bearings, the bearings that are the right size, the steel core rod which is the right size and pulleys.

[cooperman435]

Sorry if I made it sound harder than it is..........

Basically, the rollers I had were purchased from a company who repair conveyors, so they are ready made units. They have an 8mm rod sticking out already.

The bearings are 8mm Id and 22mm Od and easily obtainable through EBay for skateboard wheels. They fit into 22mm plumbing pipe clips and they are ready made to screw down.


I appreciate what you are saying, but I'll be brutally honest, if you cant research even easy to find documents on the net about the maths involved and how to assemble one of these, then I doubt your ability with the sourcing and capabilities for the rest of this hobby. I'm not trying to be harsh just that this is a relativly easy part of the whole process, chemical sourcing being the much harder part and safety being the most important of all.

[Bonny]

I'd start by looking around the web for different peoples' ball mill designs (pictures). Then see what you will need. Many hardware stores carry basic pulleys and belts. Find a local bearing shop (look in phone book) for the bearings and mounting blocks, as well as a better selection of pulleys. The bearing shop or hardware store might have the shafts too. The maths are easy, as they are simply ratios. Speeds will depend on motor speed, pulley sizes, roller size and container size. We can help you with that too, but will need some info from you first.

OR,
buy a rock tumbler to start out and do more research into making one later.

[dr thrust]

sigh! just look on good old ebay, for bearings, type in !"pillow block" these aren't that expensive and can be screwed straight to a wooden board, just select the internal size you want say 12mm,20mm ect and while your at it pick up some similar sized rod or tube, if the hole on your pulleys at bit small, you can drill it out

[Arthur Brown]

Zinginex
A simple project like a mill should be within the ability of anyone with either access to a credit card for online purchase, or access to a school workshop. A gem/rock polisher is a pretty standard piece of a school project.

[Zinginex]

lol trust me i've done a lot of reading. I just read my first post and it wasn't clear. I meant to ask where i can find the bearings and rods that will actualy fit so basically you get a bearings with, for example, 8mm ID then find a rod with a diameter of 8mm and then just knock it into the bearings?

[dr thrust]

!!!!!!!!!!!!!!! EBAY!!!!!!!!!!!!!!! arrrrgggg

[Zinginex]

!!!!!!!!!!!!!!! EBAY!!!!!!!!!!!!!!! arrrrgggg

I know you can find stuff on the web if you sift through thousands of search results from google and such but i'm just asking on a pyrotechnic forum in the pyro tools section on how to connect bearings and rollers... Ebay doesn't give out that kinda information.

[dr thrust]

ebay does give out the info in the way of a picture, if you look at a pillow block bearing you will see that there is a grub screw built into the bearing you just pass a similar sized bar though the hole a tighten up! also the block bearing is designed to screw down to a base, have a LOOK!,

Edited by chris m, 05 January 2008 - 12:19 AM.

[cooperman435]

Ok. I see where you're going. I presume you don't have a particularly engineering-based background.

The bearings supporting the rollers for the large ball mill on my website aren't attached to the rods running through them at all, they just sit loose (but as they are 8mm id bearings and 8mm bar running through them they're not actually loose per se).

As Chris M says, quite a few do have grub screws to lock down the centre of the bearing to the rod, though these tend to be the larger variety.

[Zinginex]

http://cgi.ebay.co.u...1QQcmdZViewItem

I can't see a "grub screw" in that picture but i do understnad you now. Yes i don't have an engineering background but i am capable of making a ball mill and pyrotechnics. So once a rod is secured in the bearings and they are secure down on the wooden board how do you then connect the cogs to the rollers that the belt can fit around?

[W.P]

You're probably adverse to this suggestion but why do you not purchase a chinese (the red ones with rubber barrels) from Harbour Freight so that not only are you able to mill things whilst in the process building your own ball mill you can also look at the design of the commercial mill with your own hands?

Google Harbour Freight or go to http://www.harbourfreight.com and search of rock tumblers- you can get one for price + P&P for £35 max. Expect a 2 week wait for deelivery, if you do not have the debit card to purchase the mill then sign up for one from HSBC (you just need a passport ID and your parents/guardians signature) or get your parents to purchase it (assuming they know of your hobby).