lonetreestudios
starting to spend too much on rocks
RIP Rodney, AKA @lonetreestudios
Member since December 2006
Posts: 168
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Post by lonetreestudios on Jul 24, 2012 22:39:34 GMT -5
So can anyone offer the logic behind round vs octagonal barrels, primarily in the large (45#, 60#, or more!) sizes? Seems like all the commercially available ones I find (lortone, covington) are octagonal, but there is an eBay seller (with good feedback) that says the round barrels are better for larger capacities....thoughts? Working out a tumbling rack (8 @ 40# barrels or more), and have pretty much got the plan down for making everything but the barrels, and trying to decide between round and multi-sided... Thanks for your input!
LTS
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lonetreestudios
starting to spend too much on rocks
RIP Rodney, AKA @lonetreestudios
Member since December 2006
Posts: 168
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Post by lonetreestudios on Jul 25, 2012 21:14:44 GMT -5
OK, so it should have probably said hexagonal instead of octagonal...but still, 22 views and no comments? Guess I will build round ones and if they don't work add the internal baffles.. One last shot, anyone have one of the big ones that could tell me what RPM they are turning at? Thanks... LTS
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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 Jul 25, 2012 22:29:03 GMT -5
Good Day, We run a double-5-gallon set made of 12" PVC pipe, running them at 17 R.P.M. No baffles in the barrels as I feel the kicking around of the rocks contributes to product damage. The main reason for running round barrels, other than easier construction, is they can run a little faster than hex. or oct. barrels of the same size. I don't know how to link to it; pics. of the unit toward the bottom of page 13 of the homemade section. Have about ten yrs. of run time on this unit, and get very good critiques on the finished product. There's a description of the run procedure back there, we've made a few changes to improve quality. Your questions are welcome. We also have a double 1 3/4 gallon octagon unit that works fine, but much more effort to build. The speeds we run at are from much experimentation based on the Victor's book on tumbling and baroque jewelery. Better result obtained by running 20-25% slower than what is recommended in the book.
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Jasper-hound
starting to spend too much on rocks
Member since June 2010
Posts: 208
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Post by Jasper-hound on Jul 26, 2012 0:46:55 GMT -5
I sure would like to know how you manage to keep enough food in the shop to feed those beasts! You must have a big pile, for sure.
I have a Diamond Pacific large tumbler with the same barrels that Thumler's uses. I think Hex are fine, but they had better have a rubber lining.
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Post by 3rdrockfromthefun on Jul 26, 2012 2:18:16 GMT -5
If I understand correctly, round barrels work better for most situations because, once you get a nice muddy gritty slurry going in the right consistency range, the rocks 'slide' by one another rather than being lifted a bit and dropped on one another. I believe this also results in better overall grind and less time.
No expert here - that's just my impression from reading posts and tutorials by others who tumble and an understanding of what it is a tumbler does.
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Post by johnjsgems on Jul 26, 2012 9:55:23 GMT -5
On incline barrels it is said they (all 3 manufacturers) use large flats which makes the rocks change direction, speeding up the process. I would guess on horizontal barrels the flat surfaces would stir up the mix while turning.
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Post by johnjsgems on Jul 26, 2012 20:33:43 GMT -5
Thumler's small barrels have many flat sides molded into the barrel interior. They always insisted they worked faster than smooth round barrels. If you are making PVC barrels putting in baffles would add a complication. You could probably cut a section of pipe into lengthwise strips and glue 2-4 strips in the barrel. Of course, anything you add would mean a chance to trap grit so you would probably want dedicated barrels for each grit.
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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 Jul 26, 2012 22:28:34 GMT -5
I won't enter discussion of round vs. x amount of sides on a barrel, mainly because all I've run is one octagon set, and the rest are round. The time of completion enters somewhat to us, but the end result is what counts; quality. The idea of the rocks "sliding" by each other isn't quite what is needed, a rolling, tumbling, clicking, constant motion of the rocks with no sliding [generally too slow a rotation] or banging crashing noises [too fast, where the rocks ride up in the barrel and fall on the friends below]. The proper rotational speed will give you this, and it took lots of fiddling and listening to get there, but that's half the fun of it for us. Rockbassethound: yes we have a big pile, years worth. Very careful what we pay for grit. Johnsjems: I've got the pieces together to built an incline this winter, heard they work faster, going to try it.
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colliel82
has rocks in the head
Member since November 2007
Posts: 664
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Post by colliel82 on Jul 27, 2012 8:48:57 GMT -5
Quartz I would love to see pictures as you go on building the incline tumbler as well as the results from it
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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 Jul 27, 2012 21:07:49 GMT -5
Will do colliel82, but it won't be 'till after outside stuff winds up this fall.
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