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Help Needed For Ball Mill


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#46 Arthur Brown

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Posted 02 February 2008 - 10:28 AM

B&Q sell metal rod. Usually in lengths about a metre and lots of sizes.
http://www.movember.com/uk/home/

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#47 digger

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Posted 02 February 2008 - 01:49 PM

B&Q sell metal rod. Usually in lengths about a metre and lots of sizes.


Very true, I have even been guilty of buying metal section / rod from them.

However it is an extreme rip off, have a look though your yellow pages for a local stockholder of machining metals and give them a call to see if they sell bar ends/cut lengths etc. I use a local stockholder and buy offcuts for basically scrap value (they just weigh them and I pay current scrap price) unless I am buying allot of material (Always ask for a discount when buying a decent quantity as no-one ever pays list price).
Phew that was close.

#48 Zinginex

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Posted 02 February 2008 - 08:14 PM

Very true, I have even been guilty of buying metal section / rod from them.

However it is an extreme rip off, have a look though your yellow pages for a local stockholder of machining metals and give them a call to see if they sell bar ends/cut lengths etc. I use a local stockholder and buy offcuts for basically scrap value (they just weigh them and I pay current scrap price) unless I am buying allot of material (Always ask for a discount when buying a decent quantity as no-one ever pays list price).

Ah right thanks
Well i'v just bought some skateboard bearings (8mm ID) and some 8 diameter aluminium rod of ebay. Also some pipe clips to hold the bearings down.
Should arrive soon so hopefully i'll have the rollers made sometime soon but now i need the motor and pulleys...... As i'm a complete noob im going to ask how does the pulley connect to the motor and roller shaft? Do you again just find a pulley with the same diameter as the shafts Diameter and it should be secured on? Or do you have to find threaded rods and pulleys? Or glue the pulley on?
Thanks again.

#49 cooperman435

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Posted 02 February 2008 - 09:30 PM

firstly ali rod will be no use whatsoever as it will simply bend. You need steel or stainless steel to be strong enough.

I really hope no one thinks Im being just excessivly harsh when I say (again) If you cant work out by yourself how to attatch a pulley to a motor shaft or the roller shafts then you really are going to struggle to do anything in this hobby!

The ID of the pulleys will need to be the same as the OD of the shafts there going on so they are a tight fit and then will need a securing method which could be a grub screw through the pulley or glue if its a small enough mill and will be able to cope with the load.

I fear to mention it but have you yet considered the rotational speed ot the jar and the maths needed to make it correct? the individual pulley sizes and the diameter of the rollers (when they have their friction covering on!) will all need to be used to calculate their desired rpms?

there are already a number of posts on here saying all that is needed to construct a ball mill why doesnt it appear though you have done any research already?

Edited by cooperman435, 02 February 2008 - 09:31 PM.


#50 Zinginex

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Posted 02 February 2008 - 10:12 PM

firstly ali rod will be no use whatsoever as it will simply bend. You need steel or stainless steel to be strong enough.

I really hope no one thinks Im being just excessivly harsh when I say (again) If you cant work out by yourself how to attatch a pulley to a motor shaft or the roller shafts then you really are going to struggle to do anything in this hobby!

The ID of the pulleys will need to be the same as the OD of the shafts there going on so they are a tight fit and then will need a securing method which could be a grub screw through the pulley or glue if its a small enough mill and will be able to cope with the load.

I fear to mention it but have you yet considered the rotational speed ot the jar and the maths needed to make it correct? the individual pulley sizes and the diameter of the rollers (when they have their friction covering on!) will all need to be used to calculate their desired rpms?

there are already a number of posts on here saying all that is needed to construct a ball mill why doesnt it appear though you have done any research already?


I feared al rod would maybe be to weak but it was cheap so it won't be too much of a loss.
Well I've been doing this hobby for many months now and I'm able to make starmines, salutes, fountains, make fuse, make stars, smoke compositions and such and I'm having fun and i reckon once I have a working ball mill I will be able to make more experience devces such as shells and rockets. I'm just not very engineering/technology wise. I'm just asking for help. Doesn't mean i'm incapable of the hobby.
I do know about the calculations for how to get the right rpm. I'm not a person to go out straight and waste money on pulleys and motors without thinking. I'm just trying to figure out the way you actual construct each component of the ball mill before I start the project.

Ah i thought it would be a tight enough fit to be enough friction so thankyou for that response. I guess i'll just have to keep searching... :rolleyes: lol

#51 Zinginex

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Posted 05 February 2008 - 05:00 PM

http://www.maplin.co...mp;doy=5m2#spec
http://www.maplin.co...mp;doy=5m2#spec

Hey I've found that motor and these pulleys and i just want an answer if they will be good for a ball mill? Im planning on starting out with quite a small jar, around 50 grams of bp or so and the media.
I will figure out the ratios of how to get the desired rpm but you see it says that at 6V the Rpm is 157 and then as the voltage gowes up the faster the rpm? Does that just mean the more amount of energy i give to it the faster it will run?
THanks

#52 Arthur Brown

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Posted 14 February 2008 - 08:01 PM

Bearing Blks 6mm id N31BQ 9.99 and that is for a PAIR, are bearings from maplin.

WC70M would likely make a motor for a belt drive mill

WC71N could well suit if you are to try a mill with a direct drive to the drum. Get a switched voltage PSU and use the switch to change speeds
http://www.movember.com/uk/home/

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#53 FrankRizzo

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Posted 14 February 2008 - 11:55 PM

http://www.maplin.co...mp;doy=5m2#spec
http://www.maplin.co...mp;doy=5m2#spec

Hey I've found that motor and these pulleys and i just want an answer if they will be good for a ball mill? Im planning on starting out with quite a small jar, around 50 grams of bp or so and the media.
I will figure out the ratios of how to get the desired rpm but you see it says that at 6V the Rpm is 157 and then as the voltage gowes up the faster the rpm? Does that just mean the more amount of energy i give to it the faster it will run?
THanks


Absolutely not. Those motors are nowhere near the power you need for even a modest mill. You need something that consumes at least 75W to be at all effective. While you may only be milling 50g of BP, lead media will add at least another 1.1kg with an optimal charge plus the weight of your milling barrel.

#54 Arthur Brown

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Posted 16 February 2008 - 08:48 PM

The largest mill I am aware of among the members here takes about 25kilos! It closely resembles a cement mixer!

The smallest was once pictured on the forum, it was a small drum about 3" DIA and 1" deep and milled about 10 grammes, all driven by a small stepper motor.

The 100ml 250ml and 300ml jars from
Here

Should fasten directly onto the shaft of the WC71 motor

However the efficiency of a mill with such a small drum is poor But you will get a small mill for 30
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Keep mannequins and watermelons away from fireworks..they always get hurt..




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