adrian65
Cave Dweller
Arch to golden memories and to great friends.
Member since February 2007
Posts: 10,777
|
Post by adrian65 on Sept 14, 2010 12:57:31 GMT -5
Hello everyone!
I want to set my 15 lbs hexagonal Thulmers barrel into a rotary tumbler. I decided on a 20 rpm for the barrel. My problem is: when computing the diameters of the rods, wheels, etc, should I simply take it as it is, or should I take into account some ratio adjustments to compensate the rotation speed loss due to slips? How much would that be? Could it be neglected or not? Does anyone has experience about this, when building your own tumbler?
Thank you,
Adrian
|
|
|
Post by Hard Rock Cafe on Sept 14, 2010 13:31:26 GMT -5
I admire your precision Adrian! I found I was limited by the sizes of available pulleys and settled for close enough. No doubt you'll be machining your own! For what it's worth, I've never noticed any slips with my 15 lb hexagonal barrel, unless you count belt stretching so that it's not tight on the pulleys. Chuck
|
|
drjo
fully equipped rock polisher
Honduran Opal & DIY Nut
Member since May 2008
Posts: 1,581
|
Post by drjo on Sept 14, 2010 19:27:22 GMT -5
15lbs shouldn't slip Just take into account the size of the shaft covers. Dr Joe .
|
|
adrian65
Cave Dweller
Arch to golden memories and to great friends.
Member since February 2007
Posts: 10,777
|
Post by adrian65 on Sept 14, 2010 23:21:14 GMT -5
Thank you, Chuck and Joe.
Joe, I was thinking to add some rubber bands on the barrel, not on the shafts. Is that OK? I would prefer this way 'cause if I put shaft covers, that would decrease the shafts' rotation speed so I'd need a bigger driven wheel.
Adrian
|
|
drjo
fully equipped rock polisher
Honduran Opal & DIY Nut
Member since May 2008
Posts: 1,581
|
Post by drjo on Sept 15, 2010 7:43:45 GMT -5
If you've got a material that is durable and will stay put it's not a problem.
Dr Joe
.
|
|
|
Post by jakesrocks on Sept 15, 2010 8:33:58 GMT -5
Go to your local tire store and ask for an old truck inner tube. Cut 2 bands out of it about an inch wide, and stretch them over the flat rims on the barrel. They should fit tight enough to stay put. If not, use a little bit of rubber glue. Don
|
|
adrian65
Cave Dweller
Arch to golden memories and to great friends.
Member since February 2007
Posts: 10,777
|
Post by adrian65 on Sept 15, 2010 10:10:52 GMT -5
Another idea popped in my mind: what if, instead using belts and pulleys, to attach a strong reductor (wheel and coill type) directly on the motor and then link the slow speed end of that reductor directly on the center of the lid of the barrel? The diameter of the shafts wouldn't count then, they only would become bearings for the barrel.
Any opinions? Is this system used?
Adrian
|
|
drjo
fully equipped rock polisher
Honduran Opal & DIY Nut
Member since May 2008
Posts: 1,581
|
Post by drjo on Sept 15, 2010 15:38:33 GMT -5
|
|
adrian65
Cave Dweller
Arch to golden memories and to great friends.
Member since February 2007
Posts: 10,777
|
Post by adrian65 on Sept 16, 2010 3:57:29 GMT -5
Oh, so the system is in use, and even for the high end tumblers! Thank you Dr Joe.
Adrian
|
|
drjo
fully equipped rock polisher
Honduran Opal & DIY Nut
Member since May 2008
Posts: 1,581
|
Post by drjo on Sept 16, 2010 7:47:29 GMT -5
|
|
adrian65
Cave Dweller
Arch to golden memories and to great friends.
Member since February 2007
Posts: 10,777
|
Post by adrian65 on Sept 16, 2010 12:12:06 GMT -5
;D Inventive! That motor must be including some strong reductor inside, to be linked directly to that tyre tumbler.
|
|