vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
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Post by vance71975 on Dec 26, 2022 1:50:17 GMT -5
Oh guys, need some input, I have a theory and im not sure how right or wrong it is. How much, if at all does barrel dimensions effect the tumblers effectivness?
I have a Tumble-Bee with a 4lb barrel, the dimensions are Inner diameter: 4" Outer diameter: 4-1/2" Height: 7-1/2" and I have noticed that if I fill it to the standard 2/3 to 3/4 full, the cutting action is just not good, there is barely any rock noise like the rocks are barely moving, but if I fill it half full, it works great. My girl has a komestone (similar to a nat Geo) which has a shorter but wider 2.5lb barrel, and when we fill it 3/4 full it works perfectly.
So what I am wondering is, How much does barrel width effect tumbling? Or Barrel dimensions in general?
Can any of you think of a work around with a taller barrel to be able to put more rocks in and still get an effective tumble or do you think I am just stuck running Half a barrel of rocks if I want it to work?
I have just been loading my barrel based off the standard rule of thumb of 2/3 to 3/4 full and it never even dawned on me till today that with a very tall and narrow barrel that the standard might not work. Thoughts?
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Post by HankRocks on Dec 26, 2022 6:45:07 GMT -5
The size of the barrel does affect the grinding action, more specifically the diameter of the barrel. The more space the rocks have to "fall" or "roll" down the empty area the more grinding. In addition the more weight there is in the vertical the more grinding due to increased pressure. If you carry that to an extreme, with say a 48" diameter barrel that is only 4 inch deep, the grinding action is going to be greatly increased( 4 inch deep may be too shallow as the risk of jamming may increase). If instead you use a barrel that is 4" diameter and 48 " deep, the grinding action will be greatly decreased with the reduced weight of rocks pushing down and the reduced "fall" or "roll" space.
Mix of different size rocks will also affect grind rate. I can increase the grind rate of the 4 inch diameter barrel by limiting the number of max sized rocks, 1" to 1 1/2" to maybe 2 rocks and the rest all gradually smaller and the fill not more than say 60% or so the grind rate should be ok. Add two or 3 more 1 1/2" rocks and increase the fill the grind rate will decrease. There is also the increased risk of of the rocks jamming with an increased number of large rocks.
For my model B coarse runs I usually add one rock on the order of 1/2 to 1 pound. That larger rock seems to increase the grind rate.
The rock size figures I use are all ballpark and I do not have a precise formula. On the other hand if you showed me the barrel and the mix of rocks going in and the resulting fill I would have a pretty good idea of how well the rocks will grind.
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Post by victor1941 on Dec 26, 2022 10:35:25 GMT -5
Vance71975, my observations for a UV-18 vibe are similar to HankRocks. If I want to get max movement I decrease the larger flats or larger pieces and get faster action. If I am polishing larger flats the action is slower and I run the cycle longer. The larger pieces I insert are usually petrified wood and/or the quartz nuggets found mixed in medium size decorative yard rock (1" x 3") as extra filler that I give away. I also have a large percentage of small ceramic media. I should also mention that I am vibing preforms and not rough rock.
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dshanpnw
fully equipped rock polisher
Member since December 2020
Posts: 1,071
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Post by dshanpnw on Dec 26, 2022 17:27:22 GMT -5
That is a really good question. I think Hank rocks has the answer. I have noticed the rocks in my 4 pound barrels take longer than the ones in the 12 pound barrel. There's a lot more tumbling action in the 12 pounder.
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vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
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Post by vance71975 on Dec 26, 2022 17:52:00 GMT -5
That is a really good question. I think Hank rocks has the answer. I have noticed the rocks in my 4 pound barrels take longer than the ones in the 12 pound barrel. There's a lot more tumbling action in the 12 pounder. I expected the weight of a smaller barrel to take longer, that wasnt a shock. But what I didnt expect was the standard rules of thumb to bascially be useless due to my barrel being taller than many others. That one shocked me. Like I cant really do the standard 2/3 full and get a good tumble, seems the most i can do is a fuzz over half full. I mean the fact that its quiet at 2/3 to 3/4 full is nice, but you can also tell it really isnt doing much cause there is barely any rock noise, just the noise from the motor itself. I got the 4lb barrel because I thought I could get through more rocks at once, 3/4 on a bigger barrel being more rocks logically, but considering I have to fill it 1/2 full instead of the standard it really isnt as much of an advantage in the number of rocks department as i hoped it would be lol
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Post by pebblesky on Dec 26, 2022 18:07:49 GMT -5
I remembered jamesp did some experiment in his earlier threads (can't remember which thread) that two shorter 6lbs barrel are more effective in grinding than one longer 12lb barrel with the same diameter.
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vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
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Post by vance71975 on Dec 26, 2022 18:58:48 GMT -5
I remembered jamesp did some experiment in his earlier threads (can't remember which thread) that two shorter 6lbs barrel are more effective in grinding than one longer 12lb barrel with the same diameter. Bigger around seems to work better than taller for sure from what I am seeing.
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Post by Rockoonz on Dec 26, 2022 19:53:48 GMT -5
How about surface speed? Smoothness of the barrel inside surface? I think it could be fun to take my gang tumbler rack and a homogenous material, then run batches in a variety of barrels at the same speed and fill %, then somehow record the comparitive results. Sadly all my barrels nowadays are the metal with hexagon molded inserts in 7#, 15# and 40# (45?) so expect all would run similarly. Might be fun to use the 12" and 10" pulley I replaced it with thinking it was too slow.
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Post by Rockoonz on Dec 26, 2022 19:55:48 GMT -5
I think Rob has done a few experiments on his YouTube as well.
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jamesp
Cave Dweller
Member since October 2012
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Post by jamesp on Dec 27, 2022 8:49:24 GMT -5
One question worth considering. Which would be more effective for tumbling - two 6 short pound barrels or one 12 long pound barrel, all the same diameter. The tumbling action is very different at the barrel ends as opposed to the center of the barrel. Like two Lortone QT6's verses one QT12. Particularly the uniquely shaped QT6 because it is quite a bit narrower than tall. pebblesky - I know one thing, this 24" diameter elliptical tumbler barrel would bruise and frost rocks terribly even when 3/4 full at a slow 12 rpm. Any ideas why ? The build: www.flickr.com/photos/67205364@N06/albums/72157649670517562
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dshanpnw
fully equipped rock polisher
Member since December 2020
Posts: 1,071
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Post by dshanpnw on Dec 27, 2022 8:50:08 GMT -5
That is a really good question. I think Hank rocks has the answer. I have noticed the rocks in my 4 pound barrels take longer than the ones in the 12 pound barrel. There's a lot more tumbling action in the 12 pounder. I expected the weight of a smaller barrel to take longer, that wasnt a shock. But what I didnt expect was the standard rules of thumb to bascially be useless due to my barrel being taller than many others. That one shocked me. Like I cant really do the standard 2/3 full and get a good tumble, seems the most i can do is a fuzz over half full. I mean the fact that its quiet at 2/3 to 3/4 full is nice, but you can also tell it really isnt doing much cause there is barely any rock noise, just the noise from the motor itself. I got the 4lb barrel because I thought I could get through more rocks at once, 3/4 on a bigger barrel being more rocks logically, but considering I have to fill it 1/2 full instead of the standard it really isnt as much of an advantage in the number of rocks department as i hoped it would be lol I hope some beginners will see your posting and get a better idea how to load a 3 or 4 pound barrel or figure out a reason why they are not getting the results they wanted. It's definitely slower if you put larger rocks in there that don't move around enough. Smaller rocks at 2/3 to 3/4 full should work okay.
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jamesp
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Member since October 2012
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Post by jamesp on Dec 27, 2022 9:01:13 GMT -5
assuming tumbles are 1 to 2.5 inches in size and for step 1 shaping:
I always went with 6 inch barrels at fast speeds instead of 8 inch barrels at lower speeds. In other words a shorter more gentle fall per rotation but at more rotations per time. The rocks move much faster but are not making such violent falls. The rocks are scrubbing faster without hitting each other so hard. I know this works. It's noisy though. 6 inch barrels at 60 to 70 rpm is noisy. But 4 inch barrels are too small to get much grinding action. They are just plain slow at grinding step 1.
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vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
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Post by vance71975 on Dec 27, 2022 16:37:33 GMT -5
assuming tumbles are 1 to 2.5 inches in size and for step 1 shaping: I always went with 6 inch barrels at fast speeds instead of 8 inch barrels at lower speeds. In other words a shorter more gentle fall per rotation but at more rotations per time. The rocks move much faster but are not making such violent falls. The rocks are scrubbing faster without hitting each other so hard. I know this works. It's noisy though. 6 inch barrels at 60 to 70 rpm is noisy. But 4 inch barrels are too small to get much grinding action. They are just plain slow at grinding step 1. Sadly, 4in ID barrel is what mine came with and when I got it the choice was made becuase it was cheaper than the two go to brands without all the negitive reviews of the the cheap brands like harbor freight and leegol. Sadly, I knew little about the effect of barrel diameter when I picked it. Still know little, just slightly more lol
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vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
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Post by vance71975 on Dec 27, 2022 16:40:24 GMT -5
I expected the weight of a smaller barrel to take longer, that wasnt a shock. But what I didnt expect was the standard rules of thumb to bascially be useless due to my barrel being taller than many others. That one shocked me. Like I cant really do the standard 2/3 full and get a good tumble, seems the most i can do is a fuzz over half full. I mean the fact that its quiet at 2/3 to 3/4 full is nice, but you can also tell it really isnt doing much cause there is barely any rock noise, just the noise from the motor itself. I got the 4lb barrel because I thought I could get through more rocks at once, 3/4 on a bigger barrel being more rocks logically, but considering I have to fill it 1/2 full instead of the standard it really isnt as much of an advantage in the number of rocks department as i hoped it would be lol I hope some beginners will see your posting and get a better idea how to load a 3 or 4 pound barrel or figure out a reason why they are not getting the results they wanted. It's definitely slower if you put larger rocks in there that don't move around enough. Smaller rocks at 2/3 to 3/4 full should work okay. They are not really larger rocks honestly, none of them are really over half the size of the barrel ID. Even with Say a bunch of 1/2 to 1in rocks, it still does not tumble well if its 2/3 to 3/4 full.
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dillonf
fully equipped rock polisher
Hounding and tumbling
Member since February 2022
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Post by dillonf on Dec 27, 2022 17:22:58 GMT -5
I have a a few lortones of different sizes: QT12,QT6,33B, and I just bought a 45C. I use the QTs strictly for course grinding, and I use the 33Bs for 220-polish. I used to do all steps in the 33B before I got the QTs and the larger barrels definitely grind faster. I can't really speak to the 45C yet. My hope is to do all my 220 grinding in the 45C then use the 33B for only AO grits 500,1000 & polish. I haven't noticed a big difference between the QT12 and QT6 other than I tend to get a bit more bruising in the 12 from time to time if I don't have enough ceramics. Though I must admit I usually throw one or two larger rocks in the QTs which helps the grinding (and is probably causing the bruising ). Sorry to hear that you aren't getting good grinding in the 4lber. With the tumble bee what is the design of the inside of the barrel? Is it round or a series of flat surfaces? If it is perfectly round that could negatively impact the action.
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vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
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Post by vance71975 on Dec 27, 2022 17:39:11 GMT -5
I have a a few lortones of different sizes: QT12,QT6,33B, and I just bought a 45C. I use the QTs strictly for course grinding, and I use the 33Bs for 220-polish. I used to do all steps in the 33B before I got the QTs and the larger barrels definitely grind faster. I can't really speak to the 45C yet. My hope is to do all my 220 grinding in the 45C then use the 33B for only AO grits 500,1000 & polish. I haven't noticed a big difference between the QT12 and QT6 other than I tend to get a bit more bruising in the 12 from time to time if I don't have enough ceramics. Though I must admit I usually throw one or two larger rocks in the QTs which helps the grinding (and is probably causing the bruising ). Sorry to hear that you aren't getting good grinding in the 4lber. With the tumble bee what is the design of the inside of the barrel? Is it round or a series of flat surfaces? If it is perfectly round that could negatively impact the action. Its a round smooth barrel inside with a 4in Inner diameter. It is also very tall at 7 1/2 in long.
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dillonf
fully equipped rock polisher
Hounding and tumbling
Member since February 2022
Posts: 1,622
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Post by dillonf on Dec 27, 2022 17:46:32 GMT -5
I have a a few lortones of different sizes: QT12,QT6,33B, and I just bought a 45C. I use the QTs strictly for course grinding, and I use the 33Bs for 220-polish. I used to do all steps in the 33B before I got the QTs and the larger barrels definitely grind faster. I can't really speak to the 45C yet. My hope is to do all my 220 grinding in the 45C then use the 33B for only AO grits 500,1000 & polish. I haven't noticed a big difference between the QT12 and QT6 other than I tend to get a bit more bruising in the 12 from time to time if I don't have enough ceramics. Though I must admit I usually throw one or two larger rocks in the QTs which helps the grinding (and is probably causing the bruising ). Sorry to hear that you aren't getting good grinding in the 4lber. With the tumble bee what is the design of the inside of the barrel? Is it round or a series of flat surfaces? If it is perfectly round that could negatively impact the action. Its a round smooth barrel inside with a 4in Inner diameter. It is also very tall at 7 1/2 in long. I would guess that the fact that the barrel is perfectly round inside is contributing to the problem you are experiencing. The lortone barrels have a series of flat surfaces on the inside of the barrel that aid in the tumbling action.
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jamesp
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Post by jamesp on Dec 28, 2022 14:14:41 GMT -5
According to early tumbler experts a hex barrel has a more gentle action than a perfectly round barrel. I don't know their reasoning.
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vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
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Post by vance71975 on Dec 28, 2022 15:04:57 GMT -5
According to early tumbler experts a hex barrel has a more gentle action than a perfectly round barrel. I don't know their reasoning. You would think logically that a hex barrel would be rougher consider the rocks would bounce off the flat surfaces. It would seem at least logically that a smooth walled barrel would be a more gentle roll over than a hex barrel. But that is beyond my level of knowledge.
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dillonf
fully equipped rock polisher
Hounding and tumbling
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Post by dillonf on Dec 28, 2022 16:25:02 GMT -5
According to early tumbler experts a hex barrel has a more gentle action than a perfectly round barrel. I don't know their reasoning. That is real interesting - I didn't know that!
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