ball mill rpm

[bob]

ok so I know this is a question I should be able to figure out on my own

I thought I know of some web sites that had the equation but I must have been wrong

any way the jar is 7.75 inchs wide and 10.5 inchs long and I`m using 50 cal round musket balls for media (it will be half full of media)

so what rpm should I run it at

Thanks so much

[Mumbles]

Is it 7.75" inner diameter or outer diameter?

[bob]

outer dia 7.75"

inner is about 7.25" but I couldn't get a very good measerment

Thanks

[Mumbles]

Around 64 is optimum.

[olac170]

How did you figure that out? Is there a formula or a website?

[bob]

I think this would be fine but how well would 62.57 rpm work

cause it uses a 6 inch pully insted of a 5.85 inch pully which I don't think I could get

thanks

[Mia]

How did you figure that out? Is there a formula or a website?

 

There is a formulation, but 64-68rpm is just about on the money

 

 

[Mumbles]

There is a formula to calculate optimum speed. There is a calculator on passfire which is fairly convenient. The formula was published in Lloyd Sponnenburgh's booklet on ball milling, though he's said it originally comes from commercial information and literature on industrial ball mills. Critical speed is the rpm at which the media will be stuck to the side of the jar based on centripetal force. All of the values in the formula are to be used in inches. I'm not sure how the 265.45 value is derived, but it is based upon inches.

 

Critical speed = 265.45 / sqrt (jar ID - media diameter)

 

Optimal speed is 65% of the critical speed.

[Neruda]

Hi,

 

if you want to do the calculation using centimeters instead of inches here is the formula:

 

CS= 423.06 / ( Sqr ( jar id - ball od))

[olac170]

Critical speed = 265.45 / sqrt (jar ID - media diameter)

 

Is that jar ID times media diameter?

[Mumbles]

Jar ID minus media diameter.