33 replies to this topic

[pyroboy1]

Hi
i've been looking around the web for a while and i haven't found any good sights for ball mills. can anyone help?
thanks

[Karl Mitchell-Shead]

Have a look on ebay, there are a couple of gemrocks on there at the moment, one with milling media too, search ball mill

[digger]

Look a bit on the weedy side to me (although ok for very small batches). You would soon outgrow these. For the same money you could make a far more robust mill, if you have a few hours to spare. Mine cost £25 - £30 to make (plus a few welding rods) and will easily turn 50kg.

Edited by digger, 04 February 2010 - 09:09 PM.

[Arthur Brown]

For the less mechanically adept or equipped read this page http://www.mancheste...g_Machines.html
look especially for any mill with a rubber drum they are so much quieter. There are some Evans drums for the usual Beach mills, and there are rubber drums for the 2.25kilo mill too.

[cooperman435]

Ive made plenty of them before for people and Im happy to share the info if you want.

[pyroboy1]

Ive made plenty of them before for people and Im happy to share the info if you want.

yeh can you tell me how please

[parabolic]

sorry to hyjack the thread but can I ask Arthur Brown, which of the two tumbler's between the 'beach 6.75kg with 3 rubber barrels with internal vanes or the 'evans CR2 with 3 rubber barrels with internal vanes. which would you choose?. I'm not on a budget, just want a good machine, and if the CR2 will do the job equally as good as the more expensive beach then fine, I like the sound of the evans CR2 because of the drive toothed belt. The Beech model doesn't say how its driven.

[starseeker]

sorry to hyjack the thread but can I ask Arthur Brown, which of the two tumbler's between the 'beach 6.75kg with 3 rubber barrels with internal vanes or the 'evans CR2 with 3 rubber barrels with internal vanes. which would you choose?. I'm not on a budget, just want a good machine, and if the CR2 will do the job equally as good as the more expensive beach then fine, I like the sound of the evans CR2 because of the drive toothed belt. The Beech model doesn't say how its driven.

I have been using the Evans CR2 using two larger drums rather than three small drums for well over a year now and i am very pleased,i use ceramic media (cyclebs,inoxia )and you can mill 200g batches with each drum.If you use heavier media like brass you can only use one drum.If you think this will be sufficent for the forseeable future then go for it.

[parabolic]

thanks for the quick responce

[Arthur Brown]

Firstly, use plain barrels, whichever make you chose.
Secondly, the Beach barrels are about twice the diameter of the CR2 Evans barrels. Also the Evans barrels have a screw fastener which I don't like while the Beach barrels have a rubber seal which I prefer.

Don't expect to run the full number of drums if you use lead media.

[martyn]

Just out of interest does anyone else use a 3 phase motor and an inverter to drive their mills or rollers.
A 3 phase motor can be picked up on ebay, often new, often for less than a tenner. Likewise an inverter for 30 - 40 quid.
This combination allows you to infinitely variably control the speed of rotation by easily varying the frequency from 0 - 200 % of 50 Hertz, with I believe, minimal loss of power.
I know that when mine is set to 18 Hz, the rpm is 95, which according to the passfire calculator is optimum for my jars.

I've recently bought a ridiculously large hobart dough mixing bowl to build a star roller, but I'm having a seriousl re think since seeing the great little one at the agm.

As Digger says, a pleasant half day tinkering about building your own which will be 100 times stronger than a gem polisher, is time well spent

Martyn.

Edited by martyn, 29 March 2010 - 11:04 PM.

[Arthur Brown]

If you use a speed controller you may get to the region where the motor will not self cool and needs additional cooling.

If I had a workshop I'd build all sorts of things but I don't so I buy things ready made.

[digger]

Just out of interest does anyone else use a 3 phase motor and an inverter to drive their mills or rollers.
A 3 phase motor can be picked up on ebay, often new, often for less than a tenner. Likewise an inverter for 30 - 40 quid.
This combination allows you to infinitely variably control the speed of rotation by easily varying the frequency from 0 - 200 % of 50 Hertz, with I believe, minimal loss of power.
I know that when mine is set to 18 Hz, the rpm is 95, which according to the passfire calculator is optimum for my jars.

I've recently bought a ridiculously large hobart dough mixing bowl to build a star roller, but I'm having a seriousl re think since seeing the great little one at the agm.

As Digger says, a pleasant half day tinkering about building your own which will be 100 times stronger than a gem polisher, is time well spent

Martyn.

Should not be any problem with that. You won't put the 3 phase motor under any real load I would imagine, if you are paranoid you could always hook up the the thermistor input on the inverter. I have a couple one using a 3 phase ATEX rated motor with inverter and a 200V DC motor with speed controller, both are great.

No need to calculate the optimal speed for the jar, just slowly turn it up until the media stick to the outside of the jar and it goes quiet, then just slow it down a bit till they start making a noise again. You will find this is about 70% of critical speed which is the optimum anyway. So no calculation needed.

[Deano 1]

2 years ago I made a temporary mill with a sewing machine motor and peddle, I later swapped the peddle for a bog standard light dimmer switch, I'm still using it today. Total costing was £6.50 for sewing machine (car boot)
£3.00 for 4 bearings (ebay)
half a day pottering about making it. It depends how much you want to mill in one go, bearing in mind UK law.

Edited by Deano 1, 31 March 2010 - 09:56 PM.