vance71975
has rocks in the head
Member since September 2022
Posts: 707
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Post by vance71975 on Jan 29, 2023 11:57:20 GMT -5
Is there a Universal Spacing of the drive bars that will allow you to use pretty much any barrel? If so what is the ideal distance between bars that can hold the most varied amout of barrel sizes?
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Post by Rockoonz on Jan 29, 2023 13:25:32 GMT -5
No, there is not. What size, diameter barrels do you have? jamesp is probably going to be the best source of real world data on the topic, seemed like I read a post about spacing that he authored recently in the thread about coatings on bars? The spacing for 3# barrels will not work well for any larger size, and vice versa. I am only using the metal 15 and 40 lb barrels now and the widest it is reasonable to use for the 15# will generally accomodate the 40#, but still not ideal, in fact the original Scott-Murray base that came with the 40 lb barrels was too close IMO. I currently use an upgraded 2 barrel 15# base for the 40#, but it's ready for another redo that will involve spreading them out wider and lifting the pillow blocks to clear the deck of the base. The large multi barrel base SB our next project, will dial it in to fit the 15 lb barrels, I think it was originally set up for the large diameter Lortone rubber barrels. The old factory 2 story multi barrel base I have is kinda old school modular, pillow blocks can be moved around for various barrels, you just need to find the right belts to fit the various widths. I think I'll drag out the bases and get started on something, it would be good to finally start tumbling again. |
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Post by Rockoonz on Jan 29, 2023 19:27:53 GMT -5
Okay, I looked it up, 2/3 to 3/4 of the barrel diameter seems to be the ticket. Here's the 2 bases I have. The "smaller" with the wood deck is what I have used for 15 and 40 lb barrels. Spacing is 6", so 2/3 of the 9" barrel diameter for the 15" barrels. The wide 2 story frame is also 6" on top, and I assume the 4 1/2" spacing on the bottom must have been for a 6" barrel, maybe the larger rubber Lortone barrels. I'm planning to start a separate thread on the tumbler "rebuilds", don't want to take your question all the way out into the weeds.     |
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jamesp
Cave Dweller 
Member since October 2012
Posts: 35,976
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Post by jamesp on Jan 29, 2023 21:15:07 GMT -5
I use about 60% of the barrel diameter. 6" shaft center to shaft center(big 1.5" shafts) for 6.5" and 9.5" barrels. sort of a compromise for 2 size barrels...
And have always run slick PVC or HDPE barrels directly on the steel shafts. Never had any life with rubber on shafts, not even heavy hydraulic hose.
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Post by Drummond Island Rocks on Jan 30, 2023 13:06:38 GMT -5
I use about 60% of the barrel diameter. 6" shaft center to shaft center(big 1.5" shafts) for 6.5" and 9.5" barrels. sort of a compromise for 2 size barrels... And have always run slick PVC or HDPE barrels directly on the steel shafts. Never had any life with rubber on shafts, not even heavy hydraulic hose. I never investigated to see if there was a rule of thumb specific to home built. I just did a dry mock up first. Too close and the barrels are not seated well and slippage can be an issue. Too far apart and the shafts start to pinch the barrel creating resistance on the motor. That being said my 6 and 12 pound barrels land at about 65% the diameter and my 3 pound barrels are a little closer to 70%. All three of my build have used rubber heated hose on the shafts with no issues. I wonder if that is because the barrels are all rubber VS your hard HDPE? I did learn on my first build years ago to place shaft collars at each end of the hose. I had a hose somehow migrate toward a pillow block bearing and did not notice. That ended up tearing up the bearing and shaft before I caught it. Lortone 12 pound barrel is 7.75" diameter and my shafts are 5" apart Lortone 3 pound barrel is 4.5" diameter and my shafts are 3" apart Chuck |
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jamesp
Cave Dweller
Member since October 2012
Posts: 35,976
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Post by jamesp on Jan 31, 2023 12:09:49 GMT -5
I use about 60% of the barrel diameter. 6" shaft center to shaft center(big 1.5" shafts) for 6.5" and 9.5" barrels. sort of a compromise for 2 size barrels... And have always run slick PVC or HDPE barrels directly on the steel shafts. Never had any life with rubber on shafts, not even heavy hydraulic hose. I never investigated to see if there was a rule of thumb specific to home built. I just did a dry mock up first. Too close and the barrels are not seated well and slippage can be an issue. Too far apart and the shafts start to pinch the barrel creating resistance on the motor. That being said my 6 and 12 pound barrels land at about 65% the diameter and my 3 pound barrels are a little closer to 70%. All three of my build have used rubber heated hose on the shafts with no issues. I wonder if that is because the barrels are all rubber VS your hard HDPE? I did learn on my first build years ago to place shaft collars at each end of the hose. I had a hose somehow migrate toward a pillow block bearing and did not notice. That ended up tearing up the bearing and shaft before I caught it. Lortone 12 pound barrel is 7.75" diameter and my shafts are 5" apart Lortone 3 pound barrel is 4.5" diameter and my shafts are 3" apart Chuck I did learn the hard way if the shafts are not parallel to each other the barrel would walk to one end and create a lot of rubbing on the shaft and barrel. And assist migration of hose. Not to mention wear force against the end roller. One of the garden hoses has lasted 30 years in the plant nursery. It was the only one rated for hot/cold water of the bunch. The other cold water garden hoses barely lasted 5 years. Not all hoses created equally...good that you mention heater hose. And yes, it could be the harder PVC/HDPE barrels would wear the hose quicker. In some cases like glass if you turn the tumbler off the slurry would quickly concrete to the bottom of the barrel(in like 3 minutes !) causing off-balance and more shaft-to-barrel slippage at re-start. In that case I would quickly stand them on end so the concretion would be balanced at bottom of the barrel. Why glass slurry concretes so fast is a mystery. Not PVC but HDPE will 'creep'. When a band clamp is tightened on the end of an HDPE barrel it will pinch the mouth of the barrel to a bit oval. If a larger diameter(9.5") HDPE barrel is heavily loaded with rocks and out in the hot sun not rotating it will warp a bit due to sitting on wider shafts due to pinching effect of overly wide shafts you mentioned. Remember Silly Putty ? Start up would have a lub-dub(out of round) bumpy rotation. Makes one wonder if a ruffled outside surface rotary barrel would grind rocks faster. One of the HDPE barrels was has a serious bend in the middle weld where I obviously did not cut the pipe straight across. It too has a funny wobble action. Makes one wonder if the inside of the barrel had a wedge shaped ridge running the inside circumference at the middle of the barrel if it would not increase grinding action by constantly dividing the rocks every rotation. |
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