roxgrrl
off to a rocking start
Member since October 2009
Posts: 17
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Post by roxgrrl on Nov 28, 2009 13:36:31 GMT -5
Hi everyone! Quick question: I've heard many people say that an optimum barrel volume is 2/3 full. I have a Lortone (?) QT6 barrel. I weight my loads out each time to ensure I don't exceed 6lbs. After I add water, grit, and pellets, I'm barely reaching 1/2 full. Is it okay to run with lesser volume if I'm close to the weight limit? How can I achieve the best results with a 6lb tumbler?  Thanks!  |
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Sabre52
Cave Dweller 
Me and my gal, Rosie
Member since August 2005
Posts: 20,497
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Post by Sabre52 on Nov 28, 2009 21:31:00 GMT -5
Howdy, Optimum load for the correct action in the barrel is 2/3 full as there is less drop to the load so less damage to the stones before your slurry gets thicker and there's more surface to surface action so they grind a bit faster. All that being true, as they get older, my Lortones at least, won't turn a barrel 2/3 full as it's just to darn heavy of a load once you add rocks, grit and water. Really easy to go over 10 pounds with a 2/3 full load and all the fixins. I'm actually down to running a single 1/2 full six pound barrel on my QT66 and QT12 bases. I could get away with the fuller loads when the machines were young but not any more. I run the half full barrels all the time though and they work OK but I do add some old slurry to thicken the load when running more delicate stones like quartz crystal or obsidian.....Mel
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MikeS
fully equipped rock polisher
Member since January 2009
Posts: 1,081
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Post by MikeS on Nov 28, 2009 21:43:30 GMT -5
you may try adding plastic tile spacers to make up the volume...they don't weigh much at all, shouldn't effect the motors ability to turn the barrel...
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Post by Hard Rock Cafe on Nov 29, 2009 10:05:30 GMT -5
Did you tare your scale so that you're weighing just the rock, water, etc. and not the barrel, too? If not, you could weigh the barrel separately so that you know how much that adds to the total.
I think it would help to bring the volume up with tile spacers or pellets.
Chuck
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,497
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Post by Sabre52 on Nov 30, 2009 9:19:50 GMT -5
Only comment I'd add is that if you add plastic pellets or spacers during coarse grind you will retard the grind action so the coarse phase take much longer. Rock to rock contact seems to grind much better than rock to plastic.....Mel
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chassroc
Cave Dweller
Rocks are abundant when you have rocktumblinghobby pals
Member since January 2005
Posts: 3,586
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Post by chassroc on Nov 30, 2009 10:10:06 GMT -5
Ditto to what Mel said plus...I like violence in the coarse grind...much better to have rocks fragment as early as is possible
Charlie
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MikeS
fully equipped rock polisher
Member since January 2009
Posts: 1,081
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Post by MikeS on Nov 30, 2009 22:09:51 GMT -5
It can definately be a trade-off...time vs. damage to the stones. The tile spacers will definately slow the grind. If you are working with a durable material that doesn't crack or fracture easily, you can get away with a more vigorus tumble. However, if you are working with a more brittle material that is prone to fracturing, you will want to add some volume in the form of plastic to settle the motion down a bit in the tumbler in order to perserve the stones you are working with.
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Brad
starting to spend too much on rocks
Member since July 2006
Posts: 161
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Post by Brad on Nov 30, 2009 22:33:29 GMT -5
roxgrrl,
I'm confused. Why are you trying to keep the weight under 6#?
And what weight are you trying to keep under 6#. Everything, including the barrel itself? Rocks, water, grit, & pellets?
For a grit load in my Lortone 6# barrels, I put in 4.5# to 4.75# of rock (agates, jasper, pet wood), half a cup of grit, and enough water to almost cover the rocks. (For a grit load in my 12# barrel, I double those amounts of rock & grit).
For a polish load, I put 5# of rock, half a bar of Ivory soap, water to cover the rocks, and a bunch of plastic pellets in a 6# barrel.
I've never worried about the total weight.
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rollingstone
starting to spend too much on rocks
Member since July 2009
Posts: 236
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Post by rollingstone on Nov 30, 2009 23:20:29 GMT -5
Rox,
Lortone uses exactly the same motor for their QT6, QT66 (2-6 lb barrels) and Q12 tumblers. So the limit is really 12 lbs, so go ahead and add as much rock as you wish. Until I shut mine down awhile ago to take a break from tumbling, I ran mine non-stop for almost 5 years with the barrel usually 3/4 full of rock and never had a problem.
-Don
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roxgrrl
off to a rocking start
Member since October 2009
Posts: 17
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Post by roxgrrl on Dec 5, 2009 14:13:38 GMT -5
Hey everyone, Thanks much for all the great feedback. Yes, I was weighing the everything together (barrel, grit, H2O, and rocks). No wonder I had so few in there! Have a great day!  |
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