Saskrock
fully equipped rock polisher
Member since October 2007
Posts: 1,852
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Post by Saskrock on Mar 23, 2008 0:53:18 GMT -5
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dshalldms
starting to spend too much on rocks
Member since January 2008
Posts: 113
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Post by dshalldms on Mar 23, 2008 3:51:52 GMT -5
Hi Scott,
Thank you for this timely post. I was thinking of buiding something similar, I only have one suggestion...
Instead of one offset weight, use two.
Start with them opposite each other and then move them towards each other until they are together. When they are opposite each other you would have little or no vibration. When they are superimposed the vibrations would be at their maximum.
This would be similar to the old Geode Industries... Viking Vibrasonic setup. Who never set their machine anywhere near the maximum, as this could shake the unit apart.
This is the reason why so many vibro tumblers break down!
Hope this helps,
Derek
PS You might try using rubber washers, less noisy.
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L.L.
starting to spend too much on rocks
Great Pyrenee?s Lover Extraordinaire
Member since January 2008
Posts: 135
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Post by L.L. on Mar 23, 2008 11:31:37 GMT -5
I built one using this plan and like Derek said ir probably would have been better with two offset weights to adjust the vibration. The motor I used was a continuous duty fan motor from a Hunter air filter which I thought would hold up pretty good. The motor lasted all of two hours before the vibration killed the bearings in the motor and it seized up. And it was extremely noisy when it was running. I don't know if a bucket is the best thing to use, it just seems to amplify the noise. I'm now in the process of building a whole new unit of my own design. If I can ever get around to finishing it I'll let you know how it works out.
Lee
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dshalldms
starting to spend too much on rocks
Member since January 2008
Posts: 113
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Post by dshalldms on Mar 24, 2008 6:02:55 GMT -5
Hi Lee,
Some info that may help!
The old Geode Industries Viking Vibrasonic Tumbler solved the motor problem by isolating it. This was done by using the following setup...
The double shafted motor ( motor with a through shaft ) is mounted to the main frame. There is a drive pulley at each of the motor shaft. The vibrating table is mounted to the main frame by means of 4 rubber cushioned springs.
On the underside of the vibrating table is mounted a spindle between two Plummer blocks, at each end of which is mounted two adjustable weights together with a drive pulley.
On the top side of the vibrating table is mounted the barrel. The whole system is set up so that the oscillation at either end of the table is synchronized.
The idea being to generate a high frequency vibrations of about 3000cpm and not violent oscillations.
Thus the motor being in a fixed position is isolated from the vibrations by means of the two belts. These needed to be replace on a regular basis but it's a much cheaper option than replacing motors.
Isolating the motor will solve your problems too.
Hope this helps,
Derek
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Post by deb193redux on Mar 24, 2008 11:30:15 GMT -5
Isolating the motor with a belt makes this similar to the design of Gy-Roc.
I think the Gy-Roc replacement motor might not be a bad choice if you don't have a used one. It will be built to take some amount of vibration. - or one made for a vibrating lap.
THe bowl is my chief concern. This tumbler was intended for brass and leaks were not as much of an issue. Nor was the threaded rod in the center. Maybe get a replacement bowl form a Raytech-5# of a Thumler UV-10, or even a Gy-ROC model A.
Mode vibe bowls have a cone in the center so that any penetration by the rod occurs above the waterline, or does not occur at all.
The Lot-O and Mini-sonic do not have center cones, but seem to get more of a top-to-bottom turn over instead of around the donut.
For me the most useful think would be any information on the vibration and axis of vibration needed to get this kind of roll over motion. Or, is it just bowl shape?
Been collecting infor fo a while, but still not ready to comit to a design.
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dshalldms
starting to spend too much on rocks
Member since January 2008
Posts: 113
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Post by dshalldms on Mar 26, 2008 2:45:30 GMT -5
Hi deb193redux,
In answer to your question about rotation...
Given that the drive shaft is rotating in the horizontal plane and the weights in vertical, the rotation of the load will always tend to also be in the vertical.
On the other hand, if the drive shaft is rotating in the vertical plane and the weights in the horizontal... the rotation of the load will always tend to be in the horizontal.
You will notice that in both cases I use the term ( tend to be ), this is because the shape of the container also has some influence in the rotation of the load.
In terms of efficiency...
The configuration combining ... horizontal drive shaft, vertical weights and a horizontal barrel shaped container, gives the best tumbling action.
Hope this helps,
Derek
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zarguy
fully equipped rock polisher
Cedar City, Utah - rockhound heaven!
Member since December 2005
Posts: 1,791
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Post by zarguy on Mar 31, 2008 0:45:48 GMT -5
I want to build a vibratory tumbler. The Gy-Roc 10 lb looks like what I want, but can't afford. The photos I've seen don't show enough detail for me to make my own. Does anyone have one & want to post good detailed photos, so we can build our own?
Lynn
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dshalldms
starting to spend too much on rocks
Member since January 2008
Posts: 113
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Post by dshalldms on Mar 31, 2008 3:54:23 GMT -5
Hi Lynn,
Why not try the 3lb Model B...
This together with the stacking feature and two extra bowls will almost give you the 10lbs at nearly half the cost.
This is what I intend to do as I feel it's a better option than building one.
Hope this helps,
Derek
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