Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,423
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Post by Wooferhound on Jan 26, 2017 8:17:14 GMT -5
How about some Math for your Rock Tumbler . . .
I own a Lortone 3A Tumbler which does a full rotation every second or 60 RPM.
This will be 3600 turns an hour, 86,400 turns a day, 604,800 turns a week, and 2,592,000 turns in a 30 day month.
The barrel is 4.5 inches in diameter, multiplied by Pi 3.14159 gives about 14.1 inches Circumference.
So if the barrel were rolling down the road it would travel 4230 feet an hour, 19.2 miles a day, 134.6 miles a week, and 577 miles a 30 day month.
Assuming that each rock will slide 4 inches down the other rocks during each rotation, I can guess that a rock slides 1200 feet an hour, 5.45 miles a day, 38.2 miles a week, and 167 miles in a 30 day month.
I was bored, had to do something while I'm waiting on my rocks . . .
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Post by captbob on Jan 26, 2017 9:38:19 GMT -5
Nice work. Way too lazy busy to even think about checking your math, but no wonder those rocks round so quickly with all the miles they are putting in! I had no idea that a Lortone 3 had a 60 rpm rotation speed. That's super fast compared to my large barrels.
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,423
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Post by Wooferhound on Jan 26, 2017 11:08:07 GMT -5
I don't think the RPMs matter as much as the speed that the outside of the drum is traveling. And look at the reliability of a tumbler that does 2.6 million rotations and 577 miles in a month. Slow and steady wins the race . . .
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Deleted
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Post by Deleted on Jan 26, 2017 11:21:49 GMT -5
But what is the rotational velocity? We also need a way to measure grind velocity. I propose a new unit of measure. The number of grams stone removed per hundred grams of grit. This factor can be used to measure all sorts of test parameters. Grit size comparisons, rotational velocity, barrel fill rates, slurry efficiency.... I christen this unit of measure the "Roki Factor". This in honour of the tireless testing and tumbling technological advancements originating at the Roki Shoals Tumbling Laboratory owned by our good friend Jim Price. The Roki Factor!
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,423
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Post by Wooferhound on Jan 26, 2017 11:42:34 GMT -5
>> But what is the rotational velocity? << Is that an African or European Tumbler you are asking about ? I guess my tumbler at 1 rotation per second would be 14.1 inches per second. I have great scales but never weighed the rocks.
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Post by Pat on Jan 26, 2017 11:47:43 GMT -5
My hat is off to both of you. đŸ˜€I have NEVER resorted to math when bored!!
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Deleted
Deleted Member
Member since January 1970
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Post by Deleted on Jan 26, 2017 11:56:40 GMT -5
My hat is off to both of you. đŸ˜€I have NEVER resorted to math when bored!! I'm dating a high school math teacher.
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Fossilman
Cave Dweller
Member since January 2009
Posts: 20,685
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Post by Fossilman on Jan 26, 2017 11:58:06 GMT -5
Nope nope,no math for me either-LOL
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Post by Jugglerguy on Jan 26, 2017 12:25:19 GMT -5
I love this post. If it fit in better with the curriculum I teach, I'd use it in class.
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,423
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Post by Wooferhound on Jan 26, 2017 12:29:42 GMT -5
This would tie the rock tumbling in with Math Class
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Post by captbob on Jan 26, 2017 12:40:14 GMT -5
My hat is off to both of you. đŸ˜€I have NEVER resorted to math when bored!! I'm dating a high school math teacher. Ya'll spend a lot of time talking about math?
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,159
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Post by jamesp on Jan 26, 2017 12:41:32 GMT -5
It seems even more complicated to me. The surface speed is critical no doubt. My mind works in extremes, limits and boundaries or a lack there of. As an engineer they taught us the expression "as X approaches infinity". Or "as X approaches zero".
So, if you have a barrel that is 10 feet in diameter verses 2 inches in diameter, you have to ask the effects. One foot rocks or 1 inch rocks. Tumbling lends itself to "dimensional analysis".-the ratio of the size of the rocks to the size of the barrel(for example). Dimensional analysis numbers are expressed as a ratio or multiple of ratios.
My findings of MOST critical dimensions for rotary tumblers: A good for instance of multiple ratios- a 6 inch barrel turning very fast with 1-2 inch rocks has become a favorite size(for me) for that speed-that diameter-that size rocks. To grind fast with out bruising.... Three factors------ barrel speed, barrel size and size of rocks. If you think about it, all three 'dimensions' are critical and all three play on each other. Slurry ranks high too.
Everything may change if you have a rubber or PVC barrel, or round barrel or octagonal barrel. Or thick slurry, or small media, or large media, or plastic media, or a tilted barrel, or ratio of smalls to large, or PH, or lubricants, or temperature, or water level, etc etc etc Those factors can be set up in the 'dimensionless number" to pursue optimum conditions by inserting as a divisor or multiplier.
Due to the nature of tumbling process being so variable I am highly fascinated in applying dimensional analysis to this process.
No, @shotgunner is NOT talking math.
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Post by Pat on Jan 26, 2017 12:43:22 GMT -5
In my head, math is worthless unless it ties in with real situations such as the tumbling process. As a kid, we were taught math just freely dangling in mid air. Useless.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,159
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Post by jamesp on Jan 26, 2017 12:48:45 GMT -5
In my head, math is worthless unless it ties in with real situations such as the tumbling process. As a kid, we were taught math just freely dangling in mid air. Useless. I had a math professer tell me that a runner never crosses a finish line. He just gets closer and closer in finite amounts. Math can be deceptive. Useless. You said it right Pat, "ties in with real situations". There in is the value of math. It can describe complicated arrangements that no human mind can keep a tally on by using equations and mathematical relationships EX. Tumbling
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Post by Jugglerguy on Jan 26, 2017 12:55:18 GMT -5
I'm dating a high school math teacher. Ya'll spend a lot of time talking about math? Multiplying is math.
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Post by captbob on Jan 26, 2017 13:02:11 GMT -5
Guess I won't be having lunch now ...
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,159
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Post by jamesp on Jan 26, 2017 13:06:42 GMT -5
Ya'll spend a lot of time talking about math? Multiplying is math. My life devoid of such math.
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doublet83
starting to spend too much on rocks
Member since March 2016
Posts: 118
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Post by doublet83 on Jan 26, 2017 13:14:59 GMT -5
But what is the rotational velocity? We also need a way to measure grind velocity. I propose a new unit of measure. The number of grams stone removed per hundred grams of grit. This factor can be used to measure all sorts of test parameters. Grit size comparisons, rotational velocity, barrel fill rates, slurry efficiency.... I christen this unit of measure the "Roki Factor". This in honour of the tireless testing and tumbling technological advancements originating at the Roki Shoals Tumbling Laboratory owned by our good friend Jim Price. The Roki Factor! I've been doing a lot of material removal rate experiments with a scale that is accurate to 0.01 of a gram. I'm finding that around 1.2 lbs of 80 grit removes around 1.0 lb of agate hardness rock. I am using a 15 pound high speed Thumler's tumbler. I am also finding the high speed model is significantly more efficient per lb of grit used than the regular speed, and the big 15 lbs barrel is significantly more efficient than a small 3lbs barrel. Additionally, the longer you use the coarse grit the more efficient it is, as I'm finding even after 4 days, the broken down coarse grit still has decent material removal capability. Also, initial experiments suggest the less grit you ad per charge, the more efficient the grit/material removal ratio becomes.
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jamesp
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Member since October 2012
Posts: 36,159
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Post by jamesp on Jan 26, 2017 13:49:32 GMT -5
Interesting doublet83. I have been using a high cohesion slurry thickener called 'Georgia Red Clay". It creates a lot of suction pulling the rocks together with cohesive forces. You can take 2 equal barrels equally full of rocks. One with water slurry, and one with sticky clay slurry. Lay them both down on a flat floor and roll them by hand. It is surprising how much more force it takes to roll the thick slurry barrel.(makes sense) Again, the suction is pulling the rocks together for faster grinding due to higher forces between the rocks. But also causing more rolling friction and increased load on the motor. The grit breaks down way faster due to the increased grinding force by order of 3 to 4 times faster. But, breaks the grit down so fast it behooves you to add grit daily. And what you found about less grit per charge sure enough seems to fall true. The clay lasts about a week doing daily charges before it gets tired and needs cleaning out and replacement.
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Deleted
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Post by Deleted on Jan 26, 2017 14:33:19 GMT -5
I'm dating a high school math teacher. Ya'll spend a lot of time talking about math? A lot? No... Haha thanks for asking. Some? Yes. I like a challenge. I bet you do too. Just different challenges. And I sell roofing and windows so she teaches me about some geometry math so I can solve windows ordering problems. Plus my roof measures are the best!
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