bob Posted August 15, 2012 Share Posted August 15, 2012 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 Link to comment Share on other sites More sharing options...
Mumbles Posted August 15, 2012 Share Posted August 15, 2012 Is it 7.75" inner diameter or outer diameter? Link to comment Share on other sites More sharing options...
bob Posted August 16, 2012 Author Share Posted August 16, 2012 outer dia 7.75"inner is about 7.25" but I couldn't get a very good measerment Thanks Link to comment Share on other sites More sharing options...
Mumbles Posted August 16, 2012 Share Posted August 16, 2012 Around 64 is optimum. Link to comment Share on other sites More sharing options...
olac170 Posted August 18, 2012 Share Posted August 18, 2012 How did you figure that out? Is there a formula or a website? Link to comment Share on other sites More sharing options...
bob Posted August 18, 2012 Author Share Posted August 18, 2012 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 getthanks Link to comment Share on other sites More sharing options...
Mia Posted August 18, 2012 Share Posted August 18, 2012 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 Link to comment Share on other sites More sharing options...
Mumbles Posted August 19, 2012 Share Posted August 19, 2012 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. Link to comment Share on other sites More sharing options...
Neruda Posted August 21, 2012 Share Posted August 21, 2012 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)) Link to comment Share on other sites More sharing options...
olac170 Posted August 23, 2012 Share Posted August 23, 2012 Critical speed = 265.45 / sqrt (jar ID - media diameter) Is that jar ID times media diameter? Link to comment Share on other sites More sharing options...
Mumbles Posted August 23, 2012 Share Posted August 23, 2012 Jar ID minus media diameter. Link to comment Share on other sites More sharing options...
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