[robbstech]

Hi all,
I knocked up this wee ball mill today in less than an hour and I though I would share it with you guys but mainly to get your thoughts on it, mainly safety!


It is basically an electric wheelchair motor with a used sulpher bottle on the shaft. The piece of wood is what holds the bottle to the shaft.

I was just wondering if anyone can see an dangers in my design? Also you can see that it runs on 24 volts which is great for me as no cables are needed when it runs at the bottom of the garden.

Also the white cloth is kitchen towel soaked in cold water to keep the motor cool as it tends to get quite hot.

Also the observant one amungst you will realise that the ball mill is extremely small. This is perfect size for me as I only really want to mill 100g batches at a time. (not due to the "100g rule" but more because it is a really nice number to work with and so easy to measure it out!)

Thanks for looking and please reply!
Rob

[PyroPDC]

not bad (if it works for you then thats the main thing, all i would say i wouldnt use a wet cloth as the motor is designed to get rid of the heat using the motor casing but by putting a cloth around it may make it harder to get rid of the heat, causing the motor to work harder and could burn it out.

how long of use can u get out of the 24v battery

This post has been edited by PyroPDC: 08 September 2010 - 01:02 PM

[robbstech]

PyroPDC, on 08 September 2010 - 01:01 PM, said:

not bad (if it works for you then thats the main thing, all i would say i wouldnt use a wet cloth as the motor is designed to get rid of the heat using the motor casing but by putting a cloth around it may make it harder to get rid of the heat, causing the motor to work harder and could burn it out.

how long of use can u get out of the 24v battery

I understand about the cloth, also i will get about 10 hours on 2 fully charge batteries but I have 4 so I always have 2 topped up

I think I will go ahead and use it, and I will post the results on here tonight aftera full 4 hours mill session!

[PyroPDC]

robbstech, on 08 September 2010 - 01:05 PM, said:

I understand about the cloth, also i will get about 10 hours on 2 fully charge batteries but I have 4 so I always have 2 topped up

I think I will go ahead and use it, and I will post the results on here tonight aftera full 4 hours mill session!

10hr thats a lot of use from 2 batterys.

good job anyway

[robbstech]

PyroPDC, on 08 September 2010 - 01:10 PM, said:

10hr thats a lot of use from 2 batterys.

good job anyway

Yeah it is alot of use but there is no real load on the motor so the current draw is like 2amps so actually i will get 7 hours use approx as they are both 7.5Ah each and I would never use it for more than 5 hours without charging anyway

Thanks for your comments
Rob

[maxman]

You should really be in a position to turn it on/off from a distance! I find that 1hr milling is enough when using pine or willow to make very usable lift. It also reduces the "window" for any accidents.

Maxman

[darkfang77]

What is everyone using as ball milling tubs? I can't think of a homemade type which can be durable enough.

This post has been edited by darkfang77: 09 September 2010 - 03:28 PM

[dr thrust]

best if you remove you first comment, ive seen people taken off the forum for silly remarks.
as for milling jars, cooperman sells them, inoxia sells them, ebay as a few under rock tumblers, and manchester minerals supplies them.

This post has been edited by chris m: 08 September 2010 - 07:33 PM

[robbstech]

chris m, on 08 September 2010 - 07:32 PM, said:

best if you remove you first comment

Who? Me? What is silly about it?

[robbstech]

I used the mill today to mill a 100g batch of BP, it worked beautifully and the powder was extremely fine....But when I came to light it, it was a slow burner about 2 seconds for 2 gram.
Check my other recent thread to find out more!

[dr thrust]

robbstech, on 08 September 2010 - 08:17 PM, said:

Who? Me? What is silly about it?

no not you!

[Potassium chlorate]

darkfang77, on 08 September 2010 - 07:18 PM, said:

Shame, if I had a decent watertight/airtight bottle, I'd just chuck in some ball media and throw it into washing machine for a few hours.
What is everyone using as ball milling tubs? I can't think of a homemade type which can be durable enough.

I use a piece of a 5" plastic mortar tube. The jar and the mill were made by another guy, though, from whom I bought it, but they're homemade anyway.

[robbstech]

chris m, on 08 September 2010 - 08:24 PM, said:

no not you!

[al93535]

What about pyro dust accumulating in the motor? Or a spark being produced when you make a connection to the battery?