Deleted
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Post by Deleted on Aug 12, 2011 14:15:49 GMT -5
What speed should a barrel tumble? How is it rated? I am guessing bigger ones need to go a bit faster, but that is all I can guess.
TIA
scott solar 909-957-5212
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quartz
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Post by quartz on Aug 12, 2011 23:20:31 GMT -5
Considerable experimentation settled us on running our 8", 1 3/4 gallon barrel unit at 27 R.P.M. Our 12", 5 gallon barrel unit runs at 17 R.P.M. Bigger generally means slower, rather than faster. We started our speeds using figures in "Gem Tumbling and Barque Jewelry Making", by the Victors. Found about 25% slower than their figures worked better. Product quality and the sound of the tumble [smooth tumbling sound rather than sliding or crashing and banging] are our basis of operation, and experimentation.
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Post by Rockoonz on Aug 13, 2011 3:33:28 GMT -5
those speeds put the circumference of the 8" barrel at 55.5 surface feet per minute and the 12" at 53.4 SFPM, both about the same. Do your barrels have smooth round sides or flats/ribs to stir things up? I'm sure that affects the speed needed as well.
Lee
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quartz
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Post by quartz on Aug 14, 2011 8:59:32 GMT -5
The 8" is octagon, 12" is round, smooth. 8" is UHMW plastic, 12" is PVC w/UHMW ends, both homemade. I don't like internal kickers, cause too much product damage.
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charles kuchar
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Post by charles kuchar on Aug 18, 2011 7:07:15 GMT -5
quartz, what motor are you using for your drive on the 12"? i am trying to get parts to build a 12" now. i do have a washing machine motor of 1/6th horse that would be big enough but maybe it would use to much electricity. i would just be using it for first stage tumbling. charlie
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quartz
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Post by quartz on Aug 18, 2011 13:00:29 GMT -5
Charlie, I have a 1/3 H.P. motor on the 12" unit, and yes, it takes lots of juice, about $20/ month. Each barrel [run two, five gallon capacity each] weighs very near 100 lbs. when full. Would a 1/6 would pull it at the proper speed, I really don't know. Give it a try and let us all know. Larry
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Post by Rockoonz on Aug 18, 2011 15:19:49 GMT -5
A washing machine motor may be marginal as a continuous use motor, if you decide to use it keep an eye on how hot it gets, and keep it away from flammables. I would use a capacitor start 1/4 H.P. motor either continuous duty or farm duty.
Lee
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Deleted
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Post by Deleted on Aug 20, 2011 17:13:30 GMT -5
Thanks for the input. good knowledge here.
so 50-55 sfpm seems to be a good target?
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quartz
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Post by quartz on Aug 20, 2011 22:47:21 GMT -5
Some of the people who have discussed barrel speed here on the forum use factory made tumblers, the speed seems to generally run in the 50-55 sfpm range too, likely a good starting point.
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Deleted
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Post by Deleted on Aug 24, 2011 18:14:25 GMT -5
quartz et al...
thanks for your knowledge.
shotgunner
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docharber
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Post by docharber on Aug 29, 2011 15:43:59 GMT -5
In very large tumblers, the tumbling material rolls much further with each rotation and so the RPM can be slower to get the same abrasion effect over a given period. In hobbyist size barrels up to the size of a QT-12 or larger Thumblers, about 30 RPM is fine. There's no need to be very precide in adjusting the RPM; it won't make a noticeable difference. Using the lortone QT drive pulleys and belts on a 1/2" shaft with a 1/8" vinyl coating on it will runn the tumbler at about the right speed with a motor RPM of 1500-1750 RPM. I think a lot of you are using way too large a drive motor on your machines. The QT-12 motor is only about 1/20 HP or less but works great. Once it's started, a tumbler needs little power to keep going. Keep the bearings lubed and the axles straight and true and the load on the motor will be minimal. Continuous duty HVACV motors seem to work best and you can get them free or cheap from heat and air conditioning installers. They run quieter, cooler and much cheaper than 1/3 HP appliance motors. Many are fan cooled and last indefinitely. Look at commercial machines. You will not find a small tumbler with a large motor. A balanced load on a low friction platform is the key. Placing the drive roller more directly beneath the barrel reduces motor work in starting up, too.
Mark H.
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quartz
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Post by quartz on Aug 31, 2011 11:40:21 GMT -5
Mark, Your ideas are sound and true, but in some areas [here] those motors just aren't available. I've beat myself up trying to find them, even new; in small quantities people just don't seem interested.
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docharber
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Post by docharber on Aug 31, 2011 12:47:23 GMT -5
Do you have an AC/heating repair person you use regularly? Call them. I bet they would find something for you. i just bought a replacement motor off eBay for my Gyroc to replace the Dayton TEFC moptor that came on it- totally enclosed, fan-colled, that is- for $1.25. The down side is that whiele it fits great, John at JS Gems (who would know as he rebuilds equipment) said the air over type motors will burn up without a constant air flow over them. i'm willing to test that hypothesis rather than pay over 4100 minimum to replace the motor originally supplied on the machine. TEFC motors, to my observation, have a double casing to protect them from debris that inhibits cooling. Without it, they should be OK. Now HVAC mnotors may be different, having been made, in some cases but certainly not all, to be mounted in the air stream they create. Squirrel cage blowers don't have the motor mounted in the air flow and they hold up fine. A C-frame motor is open and if you operate it with some protection from splashing and dripping, it should be fine. Just make provisions for ventilation. I also have a motor from a Xerox copuier that is 1/13 HP, dead silent, two speeds, 1300 and about 1700 RPM and cost $20 on ebay. It doesn't even get warm in use on my big tumbler (a 20 lb monster that uses Lortone QT running gear, but hich I can't seem to seal properly). It is fan cooled. Watch the Durplus site (iys in one of the thread titles here, sorry I can't go there without losing this note) as they have a number of motors that might serve the purpose at a given time in stock. If you want new and don't mind the price, there are several sites that carry a huge selection of motors. But really, at $20 a month for electricity, the smaller motor will pay for itself in no time.
Mark H.
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quartz
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Post by quartz on Aug 31, 2011 23:47:08 GMT -5
Air over motors are easy to come up with here, but not self cooled. I've contacted several places based on web sites, even at looking for six of the same motor; without fail to this point, they have not shown interest in selling to me. My money is as green as anyones, maybe my eyes are too close together, or my feet too close to the ground.
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docharber
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Post by docharber on Sept 2, 2011 0:45:14 GMT -5
if you google electric motor one of the first places that wil be listed is a fairly famous supplier - they have replacement TEFC motors like I had on my GyRoc vibe tumbler for a price, of course. I do see similar motors on ebay. You could check with a copier repairman to get a Xerox or similar copier motor from an old junked machine. As long as it's protected from drips a motor with a ventilated case, even without a fan, should work. That's what my lLortone QTs have. They get hot in use but they keep going and going and going. I hope Jon=hn is wrong about the replacement motor I got for my Gyroc. I'll know soon enough when I fire it up again.
Mark H.
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