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Post by Drummond Island Rocks on Oct 18, 2011 19:22:49 GMT -5
Can anyone tell me what the speed of the barrel is on a store bought lortone or equivalnt 3lb tumbler? We are running a homemade tumbler with lortone 3lb barrels at 37 RPM and it sure dont seem to be getting enough action.
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Post by Jack ( Yorkshire) on Oct 19, 2011 1:18:38 GMT -5
Hi D I R, I used to run 3lbs but changed to 6 lbs a tremendus difference in speed of shaping ,
But you didnt ask that
Yes your running slow I run My rocks at 42 RPM Its a home made one a Lortone barrel is 6 lbs ( It is also hextagonal inside which also helps )
You should be between 35rpm to 65 rpm I Think without looking it up Others will comment please
Jack Yorkshire uk Ps just checked The Victors Book a 4" barrel critical speed is 132Rpm Operating speed is 66RPM
A 7" barrel Critical speed 100RPM Operating speed of a 50RPM And a 10" barrel Critical speed 84RPM Operating speed 42 RPM (from results of US StonewareCompany )
So you need to run yours 2X as long to get the same results
Dont forget it is lenth that these rocks travel inside a barrel NOT the rpm that wears down the rocks and getting the right "cascade" (roughly from 10 past to 23 to on a clock face )
So Dont over fill the barrel 5/8 to 2/3rd is Ideal
Hence a bigger barel has more lenth in the cascade
Taken from "Gem Tumbling - - - - By the Victors "
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quartz
Cave Dweller
breakin' rocks in the hot sun
Member since February 2010
Posts: 3,341
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Post by quartz on Oct 19, 2011 22:14:04 GMT -5
After considerable experimenting, we found things work better for us when running our tumblers at about 75% of the speed recommended in the Victors book; this for three different size units, two round and one octagon. Play with it to make the speed work well for you.
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Post by Drummond Island Rocks on Oct 20, 2011 7:50:41 GMT -5
Thanks for the information, I am thinking I should speed up to around 50 rpms on the 3lb barrels after reading your responses. My first batch of 60/90 took 2 weeks running at 37 rpm and with a 1/3 hp motor its not cheap to run.
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jspencer
freely admits to licking rocks
Member since March 2011
Posts: 929
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Post by jspencer on Oct 20, 2011 23:01:51 GMT -5
I have a dual 3-lb.`r that normally runs about 45-50 rpms. But I also use a small C-frame 1/50th hp motor. It works well for me.
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Post by rocklicker on Oct 21, 2011 23:57:32 GMT -5
Yup about 40 RPM. Slower is better for polishing. One of my 3 pounders is a little slower and I use it for prepolish and polish.
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