jamesp
Cave Dweller
Member since October 2012
Posts: 36,557
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Post by jamesp on Dec 29, 2022 9:12:11 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! 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. Go figure. That information came from an early manual or book when rock tumbling design was at a pinnacle. Can't remember the name of the book. What happens in this barrel ? Viking Inc. put a ton of engineering into their tumblers way back when. What were their secrets in this design ?
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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 29, 2022 12:48:30 GMT -5
That is real interesting - I didn't know that! 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. Go figure. That information came from an early manual or book when rock tumbling design was at a pinnacle. Can't remember the name of the book. What happens in this barrel ? Viking Inc. put a ton of engineering into their tumblers way back when. What were their secrets in this design ? Beats me what the sceret was, looks cool as hell tho lol.
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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 29, 2022 17:27:43 GMT -5
jamesp vance71975That viking is one cool tumbler! I'm guessing it does what this one does: I thought the flat sides inside the lortone barrels aided the tumbling action because I saw this on the Rock Shed description of them: And . . . it seems kind of intuitive, but my experience with Physics 101 taught me that not everything that seems intuitive is actually accurate! So, it is cool to find out that a smooth round barrel actually has more aggressive action than a hex barrel! I have actually considered the Covington I pictured above, because it seems cool, but the price was a bit too steep.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,557
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Post by jamesp on Dec 30, 2022 6:49:06 GMT -5
jamesp vance71975That viking is one cool tumbler! I'm guessing it does what this one does: I thought the flat sides inside the lortone barrels aided the tumbling action because I saw this on the Rock Shed description of them: And . . . it seems kind of intuitive, but my experience with Physics 101 taught me that not everything that seems intuitive is actually accurate! So, it is cool to find out that a smooth round barrel actually has more aggressive action than a hex barrel! I have actually considered the Covington I pictured above, because it seems cool, but the price was a bit too steep. Round barrels and particularly large diameter round barrels work well for fast grinding for step 1 Dillon. Polishing rocks in a giant 3 foot diameter round barrel is not a good idea. Smaller diameter hex/oct barrels work best for gentler finishing and polish steps(reason below). You should consider the Covington slant barrel. Slant barrel tumblers don't have to be sealed like a horizontal barrel tumbler. The cap can be removed to view the tumble in action and add rocks/water/grit/slurry thickeners as needed. No chance of gas buildup since the cap is not sealed and allows gases to escape. They work great for gaseous loads like glass, obsidian and metals. Tumbling metals make tons of gas. My wife stole my slant hex Viking pictured above for tumbling her metal lamp parts. I have a video of it running with the cap off. The 'avalanche' of rocks is kept almost horizontal moving left to right at the longest/widest part of the barrel instead of the rocks rolling more violently down a hill(or wave) in a horizontal barrel tumbler. The steps in a hex barrel(I remember now) breaks or tips the hill 6 times per revolution in a horizontal barrel whereas a perfectly round barrel maintains a steeper more aggressive rolling hill or wave of rocks. Analogy - a shallow ocean surf with a flat sand bottom verses a deeply rippled sand bottom, the rippled sand bottom disturbs wave action from below and reduces the height of surfing waves above.
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vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
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Post by vance71975 on Jan 1, 2023 9:44:41 GMT -5
jamesp vance71975 That viking is one cool tumbler! I'm guessing it does what this one does: I thought the flat sides inside the lortone barrels aided the tumbling action because I saw this on the Rock Shed description of them: And . . . it seems kind of intuitive, but my experience with Physics 101 taught me that not everything that seems intuitive is actually accurate! So, it is cool to find out that a smooth round barrel actually has more aggressive action than a hex barrel! I have actually considered the Covington I pictured above, because it seems cool, but the price was a bit too steep. Round barrels and particularly large diameter round barrels work well for fast grinding for step 1 Dillon. Polishing rocks in a giant 3 foot diameter round barrel is not a good idea. Smaller diameter hex/oct barrels work best for gentler finishing and polish steps(reason below). You should consider the Covington slant barrel. Slant barrel tumblers don't have to be sealed like a horizontal barrel tumbler. The cap can be removed to view the tumble in action and add rocks/water/grit/slurry thickeners as needed. No chance of gas buildup since the cap is not sealed and allows gases to escape. They work great for gaseous loads like glass, obsidian and metals. Tumbling metals make tons of gas. My wife stole my slant hex Viking pictured above for tumbling her metal lamp parts. I have a video of it running with the cap off. The 'avalanche' of rocks is kept almost horizontal moving left to right at the longest/widest part of the barrel instead of the rocks rolling more violently down a hill(or wave) in a horizontal barrel tumbler. The steps in a hex barrel(I remember now) breaks or tips the hill 6 times per revolution in a horizontal barrel whereas a perfectly round barrel maintains a steeper more aggressive rolling hill or wave of rocks. Analogy - a shallow ocean surf with a flat sand bottom verses a deeply rippled sand bottom, the rippled sand bottom disturbs wave action from below and reduces the height of surfing waves above. I am not gonna say your wrong, cause im sure you know a hell of a lot more about it than I do. On a slant barrel, that makes total sense. On a standard tumbler like a flat rotary I cant wrap my brain around how a hex barrel would be smoother. I must be missing something, because logically, it would seem that as the barrel turns, the rock would hit the flat spots and bounce off rather roughly, where as in a smooth walled barrel, logically, they would simply gently roll over each other, if that makes sense. Like I cant logically see how a hex barrel with flat surfaces would be smoother.
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,432
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Post by Wooferhound on Jan 1, 2023 10:54:17 GMT -5
With a Hex walled barrel ... The rocks would be dumped off the Top in Waves instead of continuously with Round walls.
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Post by Rockoonz on Jan 1, 2023 12:24:54 GMT -5
Since the manufacturers and their product testers have reached that conclusion in the hex vs more round tumble barrel discussion I am forced to believe them. We can argue that it doesn't make sense, but decades of practice with consistent results carries more weight than our personal conclusions. I think I have a possible reason. People who have made their own barrels with smooth walled pipe often add something to keep the slurry from sticking to the wall and just sliding instead of tumbling, like flat glass or 2 surfaces that form to each other they don't want to separate. Combined with the right (wrong) surface speed that mass could be carried up to the top of the barrel where gravity takes over and the mass drops violently onto the rest of the batch. The hex barrel, on the other hand, with the slide/turn/slide/turn action, will keep everything moving at a uniform rate, and just like the interstate highway where all vehicles are traveling a roughly equal speed, there are few, if any, serious collisions. Everything stays in motion so there is more, but gentler motion. A theory anyway. What we put in the barrel is also a factor, lots of flats with few rounds and smalls can also create large sticky masses that collide more than grind, and speed plays a part, but that's a separate discussion.
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Post by mohs on Jan 1, 2023 12:31:06 GMT -5
the above is really good because I been thinking first problemohs ha just how incredible gravity works it just never fails! butte tested mostly so a question is there a screw spiral inner drum set up ? maybe with a step off at the top tuen turn tirn
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vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
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Post by vance71975 on Jan 1, 2023 19:15:37 GMT -5
Since the manufacturers and their product testers have reached that conclusion in the hex vs more round tumble barrel discussion I am forced to believe them. We can argue that it doesn't make sense, but decades of practice with consistent results carries more weight than our personal conclusions. I think I have a possible reason. People who have made their own barrels with smooth walled pipe often add something to keep the slurry from sticking to the wall and just sliding instead of tumbling, like flat glass or 2 surfaces that form to each other they don't want to separate. Combined with the right (wrong) surface speed that mass could be carried up to the top of the barrel where gravity takes over and the mass drops violently onto the rest of the batch. The hex barrel, on the other hand, with the slide/turn/slide/turn action, will keep everything moving at a uniform rate, and just like the interstate highway where all vehicles are traveling a roughly equal speed, there are few, if any, serious collisions. Everything stays in motion so there is more, but gentler motion. A theory anyway. What we put in the barrel is also a factor, lots of flats with few rounds and smalls can also create large sticky masses that collide more than grind, and speed plays a part, but that's a separate discussion. Only thing I would point out is that manufacturers care more about profit than results. I trust the users answers far more than a manufacturers because I have zero faith in companies caring about anything but profit. But your reason here makes sense, thank you because i couldnt get it to click in my brain until now.
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Post by Rockoonz on Jan 2, 2023 1:46:25 GMT -5
Since the manufacturers and their product testers have reached that conclusion in the hex vs more round tumble barrel discussion I am forced to believe them. We can argue that it doesn't make sense, but decades of practice with consistent results carries more weight than our personal conclusions. I think I have a possible reason. People who have made their own barrels with smooth walled pipe often add something to keep the slurry from sticking to the wall and just sliding instead of tumbling, like flat glass or 2 surfaces that form to each other they don't want to separate. Combined with the right (wrong) surface speed that mass could be carried up to the top of the barrel where gravity takes over and the mass drops violently onto the rest of the batch. The hex barrel, on the other hand, with the slide/turn/slide/turn action, will keep everything moving at a uniform rate, and just like the interstate highway where all vehicles are traveling a roughly equal speed, there are few, if any, serious collisions. Everything stays in motion so there is more, but gentler motion. A theory anyway. What we put in the barrel is also a factor, lots of flats with few rounds and smalls can also create large sticky masses that collide more than grind, and speed plays a part, but that's a separate discussion. Only thing I would point out is that manufacturers care more about profit than results. I trust the users answers far more than a manufacturers because I have zero faith in companies caring about anything but profit. But your reason here makes sense, thank you because i couldnt get it to click in my brain until now. Did you know that the originators of one of the largest sellers of rock tumblers personally took their wares to Quartzsite every winter years ago, then went to mexico to rockhound before returning? They filled those profitable barrels with their own rocks and tumbled them. I was blessed to be able to sit in on sales meetings with their grandson, who now runs the company and also is still personally a rockhound and lapidary. Sure, they aren't running a non profit but they do know more about their product than the average user and have spent a lot of time developing machines that will do the job by using them. Profits are directly connected to the product performing as promised, typically with tools the failures tend to be more frequently connected to the ability of the user to follow the directions.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,557
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Post by jamesp on Jan 2, 2023 5:16:49 GMT -5
With a Hex walled barrel ... The rocks would be dumped off the Top in Waves instead of continuously with Round walls. Like that vance71975. A round barrel maintains the highest 'avalanche within' or 'hill of rolling rocks' and causes harsher impacts. A hex barrel disrupts and lowers or tips the 'avalanche within' 6 times a rotation. Or it could be said that the rocks stay flatter across the inside of a hex barrel.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,557
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Post by jamesp on Jan 2, 2023 5:37:44 GMT -5
Since the manufacturers and their product testers have reached that conclusion in the hex vs more round tumble barrel discussion I am forced to believe them. We can argue that it doesn't make sense, but decades of practice with consistent results carries more weight than our personal conclusions. I think I have a possible reason. People who have made their own barrels with smooth walled pipe often add something to keep the slurry from sticking to the wall and just sliding instead of tumbling, like flat glass or 2 surfaces that form to each other they don't want to separate. Combined with the right (wrong) surface speed that mass could be carried up to the top of the barrel where gravity takes over and the mass drops violently onto the rest of the batch. The hex barrel, on the other hand, with the slide/turn/slide/turn action, will keep everything moving at a uniform rate, and just like the interstate highway where all vehicles are traveling a roughly equal speed, there are few, if any, serious collisions. Everything stays in motion so there is more, but gentler motion. A theory anyway. What we put in the barrel is also a factor, lots of flats with few rounds and smalls can also create large sticky masses that collide more than grind, and speed plays a part, but that's a separate discussion. Yep, I got nailed by the slippage problem Lee. There was a guy selling 8" PVC barrels on EBAY so I bought one 12 years ago and decided to build my first rotary tumbler. Completed the tumbler and set it up at a typical 25 rpm for an 8" barrel only to find out the rocks were slipping instead of tumbling. Called the guy and told him the problem. He said the barrel had to spin at least 40 rpm to prevent slipping. But a 40+ rpm 8 inch barrel was OK for step 1 coarse grind and too violent for finish and polish steps. Read about slurry. So I got a the idea to add sticky clay to the batch and that stopped the slippage at 25 rpm.
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Post by Rockoonz on Jan 2, 2023 10:46:44 GMT -5
Since the manufacturers and their product testers have reached that conclusion in the hex vs more round tumble barrel discussion I am forced to believe them. We can argue that it doesn't make sense, but decades of practice with consistent results carries more weight than our personal conclusions. I think I have a possible reason. People who have made their own barrels with smooth walled pipe often add something to keep the slurry from sticking to the wall and just sliding instead of tumbling, like flat glass or 2 surfaces that form to each other they don't want to separate. Combined with the right (wrong) surface speed that mass could be carried up to the top of the barrel where gravity takes over and the mass drops violently onto the rest of the batch. The hex barrel, on the other hand, with the slide/turn/slide/turn action, will keep everything moving at a uniform rate, and just like the interstate highway where all vehicles are traveling a roughly equal speed, there are few, if any, serious collisions. Everything stays in motion so there is more, but gentler motion. A theory anyway. What we put in the barrel is also a factor, lots of flats with few rounds and smalls can also create large sticky masses that collide more than grind, and speed plays a part, but that's a separate discussion. Yep, I got nailed by the slippage problem Lee. There was a guy selling 8" PVC barrels on EBAY so I bought one 12 years ago and decided to build my first rotary tumbler. Completed the tumbler and set it up at a typical 25 rpm for an 8" barrel only to find out the rocks were slipping instead of tumbling. Called the guy and told him the problem. He said the barrel had to spin at least 40 rpm to prevent slipping. But a 40+ rpm 8 inch barrel was OK for step 1 coarse grind and too violent for finish and polish steps. Read about slurry. So I got a the idea to add sticky clay to the batch and that stopped the slippage at 25 rpm. Did you glue baffles inside the barrels? Seems I've heard of people doing that also to break up the slide action. Seems like problem solving with tumbling can be a bit of a moving target situation if you tumble a variety of shapes/hardnesses and want to find a universal solution.
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Post by HankRocks on Jan 2, 2023 12:05:21 GMT -5
Since the manufacturers and their product testers have reached that conclusion in the hex vs more round tumble barrel discussion I am forced to believe them. We can argue that it doesn't make sense, but decades of practice with consistent results carries more weight than our personal conclusions. I think I have a possible reason. People who have made their own barrels with smooth walled pipe often add something to keep the slurry from sticking to the wall and just sliding instead of tumbling, like flat glass or 2 surfaces that form to each other they don't want to separate. Combined with the right (wrong) surface speed that mass could be carried up to the top of the barrel where gravity takes over and the mass drops violently onto the rest of the batch. The hex barrel, on the other hand, with the slide/turn/slide/turn action, will keep everything moving at a uniform rate, and just like the interstate highway where all vehicles are traveling a roughly equal speed, there are few, if any, serious collisions. Everything stays in motion so there is more, but gentler motion. A theory anyway. What we put in the barrel is also a factor, lots of flats with few rounds and smalls can also create large sticky masses that collide more than grind, and speed plays a part, but that's a separate discussion. Yep, I got nailed by the slippage problem Lee. There was a guy selling 8" PVC barrels on EBAY so I bought one 12 years ago and decided to build my first rotary tumbler. Completed the tumbler and set it up at a typical 25 rpm for an 8" barrel only to find out the rocks were slipping instead of tumbling. Called the guy and told him the problem. He said the barrel had to spin at least 40 rpm to prevent slipping. But a 40+ rpm 8 inch barrel was OK for step 1 coarse grind and too violent for finish and polish steps. Read about slurry. So I got a the idea to add sticky clay to the batch and that stopped the slippage at 25 rpm. I suspect that un-lined metal barrels or PVC barrels will have more slippage of rocks. The rubber barrels, or rubber lined barrels should have a higher coefficient of friction and the individual rocks contacting the side should be more likely to tumble a bit. I did a quick non-scientific test and pushed a 1 inch rock against the a Model B barrel and the same rock against the side of a non painted piece of metal. The metal resisted sliding a bit less than the lined barrel. Then there the whole issue of slurry and how it affects my observation. As mentioned the perfect round barrel(for coarse runs) would have slight baffles on the walls to increase the "churn". I am sure the perfect baffle would probably have an angled side towards the oncoming rocks so as not to create a trap for any smalls. I am getting a headache, fortunately my Model B barrels do a pretty good job of grinding which I measure by how much grit is broken down in a normal coarse run.
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vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
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Post by vance71975 on Jan 2, 2023 18:52:16 GMT -5
Yep, I got nailed by the slippage problem Lee. There was a guy selling 8" PVC barrels on EBAY so I bought one 12 years ago and decided to build my first rotary tumbler. Completed the tumbler and set it up at a typical 25 rpm for an 8" barrel only to find out the rocks were slipping instead of tumbling. Called the guy and told him the problem. He said the barrel had to spin at least 40 rpm to prevent slipping. But a 40+ rpm 8 inch barrel was OK for step 1 coarse grind and too violent for finish and polish steps. Read about slurry. So I got a the idea to add sticky clay to the batch and that stopped the slippage at 25 rpm. I suspect that un-lined metal barrels or PVC barrels will have more slippage of rocks. The rubber barrels, or rubber lined barrels should have a higher coefficient of friction and the individual rocks contacting the side should be more likely to tumble a bit. I did a quick non-scientific test and pushed a 1 inch rock against the a Model B barrel and the same rock against the side of a non painted piece of metal. The metal resisted sliding a bit less than the lined barrel. Then there the whole issue of slurry and how it affects my observation. As mentioned the perfect round barrel(for coarse runs) would have slight baffles on the walls to increase the "churn". I am sure the perfect baffle would probably have an angled side towards the oncoming rocks so as not to create a trap for any smalls. I am getting a headache, fortunately my Model B barrels do a pretty good job of grinding which I measure by how much grit is broken down in a normal coarse run. I have considered when I build my home made tumbler making a large diameter PVC barrel and taking Small Diameter PVC pipe,cutting it in half and welding the half pipes inside the large barrel to increase the tumbling action with little half circle archs. Not sure how of a good idea it is, but its a thought.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,557
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Post by jamesp on Jan 3, 2023 4:12:03 GMT -5
Yep, I got nailed by the slippage problem Lee. There was a guy selling 8" PVC barrels on EBAY so I bought one 12 years ago and decided to build my first rotary tumbler. Completed the tumbler and set it up at a typical 25 rpm for an 8" barrel only to find out the rocks were slipping instead of tumbling. Called the guy and told him the problem. He said the barrel had to spin at least 40 rpm to prevent slipping. But a 40+ rpm 8 inch barrel was OK for step 1 coarse grind and too violent for finish and polish steps. Read about slurry. So I got a the idea to add sticky clay to the batch and that stopped the slippage at 25 rpm. Did you glue baffles inside the barrels? Seems I've heard of people doing that also to break up the slide action. Seems like problem solving with tumbling can be a bit of a moving target situation if you tumble a variety of shapes/hardnesses and want to find a universal solution. I never tried the the baffles Lee HankRocks vance71975The slurry took care of the problem. But I added a set of slow shafts for finishing steps 2-3-4 and continued to run step 1 at faster speeds. It was surprising to see how quickly a nice polish was made running the barrel slow. Clay did well for step 1-2-3, and sugar did the trick for polish. Clay slowed the polish process probably due to the sharp quartz sand particles in the clay so sugar was used instead for polish. Used the rotary for a few years until finally buying a vibe to do steps 2-3-4. Of course the vibe does a faster job. On a side note a 5/8 full barrel slipped more than 2/3 full barrel, and a 2/3 full barrell more than a 3/4+ full barrel. So barrel fill affected slippage too. And anytime slippage occured in step 1 the PVC would wear quickly. I did glue some PVC inserts to thicken the pvc wall and end cap to lengthen the life of the PVC: www.flickr.com/photos/67205364@N06/sets/72157672945278964Worn out PVC barrels(I switched to HDPE pipe barrels) Back lighting shows thin spot in pvc end cap:
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Post by Bob on Feb 8, 2023 23:26:37 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. I'm running 3 x Lortone 12lb barrels and 3 x 6lb barrels. My experience is the opposite of this. That's one reason why I wish I didn't have the 6lb barrels.
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