rrod
having dreams about rocks
Member since December 2020
Posts: 72
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Post by rrod on Nov 9, 2021 11:42:51 GMT -5
Now that I have two Thumler's B bases, I thought it would be fun to test out having one set up for a slower (say 1/2) tumble speed. I've tried looking for any variation of gear that would slow things down: a smaller motor pulley, a larger shaft pulley, a straight-up slower motor, but it's hard to know what will actually work. Anyone have suggestions?
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Post by Rockindad on Nov 9, 2021 20:24:26 GMT -5
What does yours spin at now? While I really like ours, it is mostly for the barrels. The machines themselves are already pretty slow. Our older one only rolls at 19 rpm's, the other one at 21-22. Couldn't imagine slowing them down and will probably abandon the Thumler frames/motors for a homemade setup.
As to your question- I don't know how much of a smaller pulley you are going to find for the motor shaft, it is already pretty small. As far as the shaft/axle pulley you will run into clearance issues quickly as the factory pulley only clears the base by a 1/4" or so. Willing to cut the base? If you are really determined look into a variable speed DC motor, see if you can get a free/cheap treadmill on Craigslist.
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rrod
having dreams about rocks
Member since December 2020
Posts: 72
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Post by rrod on Nov 9, 2021 22:01:09 GMT -5
What does yours spin at now? While I really like ours, it is mostly for the barrels. The machines themselves are already pretty slow. Our older one only rolls at 19 rpm's, the other one at 21-22. Couldn't imagine slowing them down and will probably abandon the Thumler frames/motors for a homemade setup. As to your question- I don't know how much of a smaller pulley you are going to find for the motor shaft, it is already pretty small. As far as the shaft/axle pulley you will run into clearance issues quickly as the factory pulley only clears the base by a 1/4" or so. Willing to cut the base? If you are really determined look into a variable speed DC motor, see if you can get a free/cheap treadmill on Craigslist. Thanks for the reply! This is all part of my continuing obsession with tumbling labradorite. The B spins about 20rpm, but since it's about 1.5 times the diameter of the 3lb Thumler barrels (which spin at 30rpm on the A-R1), the linear velocity at the edge of the tumbling space is pretty much the same. I might be willing to cut the base (and table, I guess) if I had any skills at using rotating sharp things, but I don't So you're suggestion for a variable DC motor is probably the way to go, though it would be nice if these things came with one in the first place!
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Post by holajonathan on Nov 15, 2021 3:29:51 GMT -5
I've got a model B and and two model B copies that spin twice as fast. I've tumbled a whole lot of rocks in the model B, and I've never got the sense that it was damaging rocks based on the speed. To the contrary, it is the most gentle tumbler I own, and I've got a whole bunch of different tumblers. Labradorite is just a naturally fractured rock that will drive you crazy until you surrender. I hope you prove me wrong. As for tweaking the model B, you could slow it slightly with a TRIAC speed controller. This is like a dimmer and simply reduces the AC voltage. Lower voltage also lowers torque, however, so as a practical matter you might only be able to reduce speed by 10-20% while still having enough torque to spin the barrel.
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