635 replies to this topic

[cooperman435]

I recommend building one out of 10mm polycarbonate, its see-through and its bullet proof.

Not if made into the jar its self! Its impact resistant not pressure proof! it would act as any other container would do if powder was ignited inside and explode!

[pyrotrev]

It might be worth mentioning that wooden milling barrels have been used for milling BP - I think it was either Italian or Maltese factories, maybe Karlfoxman can confirm that. Obviously you'd need to use a fine grained timber and probably varnish it and use for one mix only, however it does make building an octagonal barrel (with round end pieces for drive) very easy so it might be of interest.

[ridley]

sssssssssssssssssssss

Edited by ridley, 14 February 2015 - 09:59 PM.

[ridley]

Hi,

Do you think these would be a good source for rollers for a ball mill/star roller?

http://cgi.ebay.co.u...bayphotohosting

Ridley

[Bonny]

Hi,

Do you think these would be a good source for rollers for a ball mill/star roller?

http://cgi.ebay.co.u...bayphotohosting

Ridley

I'm sure they will be fine.

[kelly]

There seems to be a lot of concern about media for milling. Try getting lug nuts from the auto wreckers, I got enough to fill a 5 litre bucket for the cost of a $6.00 donation to the Red Cross tin. Okay so they are steel, but these are only used in my charcoal drum. As for brass media, someone mentioned that they got sparks from brass, well as a nonferrous metal (a metal NOT containing carbon) this is impossible! I don't know where the sparks came from but it certianly was not from brass!!!!

kelly

[Bonny]

There seems to be a lot of concern about media for milling. Try getting lug nuts from the auto wreckers, I got enough to fill a 5 litre bucket for the cost of a $6.00 donation to the Red Cross tin. Okay so they are steel, but these are only used in my charcoal drum. As for brass media, someone mentioned that they got sparks from brass, well as a nonferrous metal (a metal NOT containing carbon) this is impossible! I don't know where the sparks came from but it certianly was not from brass!!!!

kelly

As you said, if someone got sparks from brass, it was not pure brass. I wouldn't recommend using steel on anything, including charcoal. Once milled, that charcoal could contain steel particles, making it risky to use making BP etc...in a ball mill.

[Arthur Brown]

If you search http://rswww.com ( and probably farnell and CPC ) for conveyor rollers you will find plastic and steel and stainless rollers in various widths and various load capacities up to hundreds of kilos so you could have the makings of drum rolling support for 200kilos with ease! that way you would not be overloading the mill with milling a few g of powder using a few kilos of lead.

You can also get powered rollers which run off mains or 24vdc -- instant 200kilo ball moll but at a price!!

[Caramanos2000]

Anyone have one of these: http://pyrocreations...c/sdetail/11960

[smomi]

Right now I'm building a new ball mill and it will have a jar with dimensions of 25cm x 10.2cm I.D (9.84" x 4.02"). The media I will use will be brass cylinders filled with lead. What would be the best dimensions for my media?

Progress so far:

http://img126.images...dsc00036wz5.jpg
http://img524.images...dsc00037ca0.jpg
At the moment I'm covering the screwholes with some filler. After that it will be painted white to immediately notice if the jar is leaking or if any other dust is falling on it.

Sry for bad English.

[pyrotrev]

Anyone have one of these: http://pyrocreations...c/sdetail/11960

I like the warning about not milling flash !!!!!

Edited by pyrotrev, 23 June 2008 - 12:25 PM.

[Hi-Fi.re]

Hi Everyone,

Recently started taking steps towards making my own Ball Mill. Well what a carry on, most topics claim that 65% critical speed is key, so after putting in the mills measurments on passfire ive got completely stuck, here are my results.

Jar ID - 5"
Media OD - 0.669" (17mm)
Critical Speed - 127 Rpm
Optimal Speed - 82 Rpm

So what does the Critical Speed have to be 65% of ?

Thanks for any help.

[cooperman435]

The critical speed is the rpm that would cause your media to be held against the jar sides by inertia. Optimal speed is the rpm needed (65% of the critical speed) to get the best milling action from your setup


SO

critical speed IS 127rpm
optimal speed IS 82rpm which is 65% of the critical speed.

Edited by cooperman435, 04 August 2008 - 07:51 PM.

[Hi-Fi.re]

Ohhhh Makes it sound so simple now.

[paul]

It might be worth mentioning that wooden milling barrels have been used for milling BP - I think it was either Italian or Maltese factories, maybe Karlfoxman can confirm that. Obviously you'd need to use a fine grained timber and probably varnish it and use for one mix only, however it does make building an octagonal barrel (with round end pieces for drive) very easy so it might be of interest.

I´ve got a book solely on the history and manufacture of BP and I can assure you, nearly every country used to use these.
They most often had a liner of leather inside... Often even hard-wood balls were used, but most of the time brass...


Book: Schwarzpulver und Sprengsalpeter

I recommend this book to everyone who speaks a bit German. A pitty that great book is not available in English language.
Nearly 500 pages about BP manufacture now and then, ball milling and lots of very very interesting patents...