39 replies to this topic

[Pyromaster2003]

why do you need a mortar for your ball mill? What company are you talking about at the end, you have not mentioned a name, just some details of the chemicals...

[pyrotechnist]

I mean't a motor. I can't find a suitable motor for my ball mill.

Edited by Richard H, 06 December 2003 - 01:49 PM.

[Matt]

I use a desktop fan motor, dont say you cant pick up them at op shops for a couple bucks....

-Matt

[pyrotechnist]

Does it work ok for the job? I did have a fan once but chucked it because it had faults and it probably wouldn't have worked anyway for it it was giving up. Does it connect to the main power supply of the house as these motors are dear here in the UK.

[Richard H]

Has any one baught anything from here yet? Has any one heard of this company?  It has listed potassium perchlorate, sulphur, strontium salts, barium salts, and many more chemicals useful for pyro.
http://www.brettmart...istance_2.shtml.

No, this website is simply listing the chemical resistance of it's products to the aforementioned chemicals.

I've had to edit your posts because I'm finding them really hard to read. If the SPG does not get much better I might have to start previewing your messages before they go live.

[Richard H]

I mean't a motor. I can't find a suitable motor for my ball mill.

Why don't you just use a motor from a washing machine? Go down to your local scrap yard or household repairs place and pick one up second hand.

[pyrotechnist]

Ho dam I went to fast at the end and didn't look at it I forgot. I will be more careful thanks for telling me i will look more Frequently and modify errors. Could do that as long as it works ok.

Edited by pyrotechnist, 06 December 2003 - 08:38 PM.

[Frozentech]

I am in the process of making a ball mill so I went down to our local tip to get a washing mashine motor and managed to pick one up for free. However i now have the problem of gearing it down to the correct speed. Washing machines normally have a slow cycle, could this be helpful? Any information would be great?
Regards
P.S I didn't know where to put this post and didnt want to start a new thread just for the question...

Use a belt drive, with pulleys. For example, if your motor turns at 1274 RPM: driving a 2" pulley, to a belt drivnig a 6" pulley which turns a 1" diameter drive roller, turning a 6" diameter milling jar, the jar wil roll at 70 RPM.

If you can, read Lloyd Sponenburgh's book, "Ball Milling Theory and Practice for the Amateur Pyrotechnician". All this info, and much more, including explicit plans for ball mills can be found there. Passfire also has a wealth of ball mill design info.

[Jerronimo]

Yes, that's a very nice idea pyromaniaman,never heard of a thyristor before.
But what about power/torgue?
Normally u reduce rpm by pullies, so the motor keeps making 1400 rpm.
So almost(some friction and heat)all the power will be used.
But if u reduce rpm with a thyristor I don't think the motor will be ass powerfull, because u don't use it's full potential.

[littlejohny]

go here 27 pages of ball mill info.

[pyromaniac303]

I also have an intrest in electronics and a thyristor (as I understand it) is a kind of bistable / latch, with 3 pins:

Drain pin: Connects between the load and the power supply, has to stay at the same or higher voltage than the source pin.

Source pin: Connects to the 0v end of the circuit.

Gate pin: Acts as a latch, when a certain voltage level is reached it decreases the resistance between the other 2 pins and allows the load to operate. And even when the voltage on this pin is no longer present the resistance remains low until either power is switched off to the entire circuit, or the thyristor is shorted out.

article on thyristors

I don't see how this would fit in to a ball mill, and I would have thought that a PWM speed controller should be a much more efficient way of controlling the RPM. Even a potentiometer / variable resistor would offer a simple but less efficient approach.