herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
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Post by herchenx on May 22, 2013 23:08:02 GMT -5
Thanks for all the help working out a formula for this big tumbler. I ended up ordering 46/70 SiC from therockshed.com. My big scale is not working, so based on my guess at the weight I drafted a formula based on 70# of rock. I had thought it was closer to 100# but lifting it again it didn't seem that heavy. I weighed 1 cup of the grit and it was almost exactly 12oz in my measuring cup. I put 9.5 cups of the grit in to give me just over 7# of grit. Water to just below the top layer of rocks, oiled up the motor and all the pillow bearings on the beast, buttoned it all up and fired it up. I'm going to let it run long so it chews up all the grit well. Maybe open it in 2 weeks to see how things look. Sent from my phone. Attachments:
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Post by johnjsgems on May 23, 2013 10:26:38 GMT -5
Must be "Contempo Lapidary" badged tumbler by the color. I had a 40 lb. version. I see the Contempo owner every year at Tucson.
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Steve
has rocks in the head
Member since June 2005
Posts: 506
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Post by Steve on May 23, 2013 10:35:51 GMT -5
Are you going to take up weight lifting to stay in shape for the care and feeding of the beast?
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on May 23, 2013 11:25:00 GMT -5
I feel the ground shaking here in Atlanta.Beware of avalanche in winter.
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Post by johnjsgems on May 23, 2013 11:28:25 GMT -5
I'm a decrepit old man but was amazed at how heavy the 40lb. metal drum with liner, rocks, and grit weighed. It was a workout for sure. I don't envy John with his monster. The 1/3 hp motor running 24/7 raised my electric bill about $30 per month. I never noticed my little Thumler's having any effect.
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Post by Drummond Island Rocks on May 23, 2013 11:47:30 GMT -5
that's a lot of rocks to be rolling in one barrel. I thought I had read somewhere on here to use "about" one tablespoon of grit per pound of rock in the first stage? If i did my math right 9.5 cups is 152 tablespoons of grit. But then again if you leave it rolling for two weeks then going heavy on the grit might be a good idea.
Chuck
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herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
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Post by herchenx on May 23, 2013 12:01:16 GMT -5
Must be "Contempo Lapidary" badged tumbler by the color. I had a 40 lb. version. I see the Contempo owner every year at Tucson. I had been told that these guys sold to someone else. Diamond Pacific had a 65t tumbler that matches the specs of mine. So are they still in business? Sent from my phone.
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herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
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Post by herchenx on May 23, 2013 12:03:40 GMT -5
that's a lot of rocks to be rolling in one barrel. I thought I had read somewhere on here to use "about" one tablespoon of grit per pound of rock in the first stage? If i did my math right 9.5 cups is 152 tablespoons of grit. But then again if you leave it rolling for two weeks then going heavy on the grit might be a good idea. Chuck I had several different formulas I looked at. The 1# (grit) per 10# (rock) seemed closer to the ratio I use in my smaller tumblers. I'll see in 2 weeks how it did! Sent from my phone.
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quartz
Cave Dweller
breakin' rocks in the hot sun
Member since February 2010
Posts: 3,340
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Post by quartz on May 23, 2013 15:26:40 GMT -5
You used the same amount of grit/weight I do in our 50# drum, gets used up in 10 days. 2 wks. should eat it up pretty well. I base ours differently, 1 lb. per gallon of capacity [ours is 5 gallon], but it works out the same.
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