DIY question on mechanical stuff

[eVe GiiDiiOn]

My son likes to watch Myth Busters. After watching it he now wants to build something and decided on a rock tumbler. I tried to buy one, but he wanted to build it. I figured we could use a piece of PVC pipe with a "cleanout(?)" connector on one end and a plug on the other. I figured we'd need some kind of motor to turn it, which I can buy at a local shop. My problem is connecting the motor to the pipe. Any suggestions on how to do this? I figured I could use something like roller blades to rest the pipe on and allow it to turn. Any suggestions for the project? I realize this is off topic, but I'm afraid while I read this group to figure out how to do some home repairs, I need suggestions on this from some one who is mechanically inclined. His father is not part of his life and in some areas I'm not a very good replacement.

I"m also looking for a active rock group (yes I see the pun) in which to post this message.

Thanks

[Richard J Kinch]

Look no further:

[prfesser]

Caution advised. Is this the episode wherein the Mythbusters make black powder using a rock tumbler? There are all sorts of ways to hurt oneself and others, and to bring the ire of humorless officials including police, lawyers, judges, etc., with this sort of activity.

[Eric in North TX]

That's only because we live in a nanny / police state. Have you noticed the more nanny like the laws become the more outrageously people behave, kind of a boomerang effect.

[Jack]

I'll totally agree with that. But try getting the general public to see it. As I see the picture this nation will never recover until it becomes ruled by a Despot who lays down the law and controls everything. If that turns out to be a good one then all will be well. But the odds are that will not be so and we will beome another Iraq. Its been coming along for a long time as you say with the nanny laws making it happen.

Jack

[hallerb]

bush is doing his best to ruin our nation, trying to make it a police state...........

spying on americans tracking all calls, the only reason they dont record them is data handling isnt up to it yet, but never fear it will be soon.

remember that old twilight zone episode with a idiot turning in others for a wide variety of implied infractions?

this time it will be big brother who has the noose on you

king bush is just disappointed he will be neuutered by this election

[hallerb]

bush is doing his best to ruin our nation, trying to make it a police state...........

spying on americans tracking all calls, the only reason they dont record them is data handling isnt up to it yet, but never fear it will be soon.

remember that old twilight zone episode with a idiot turning in others for a wide variety of implied infractions?

this time it will be big brother who has the noose on you

king bush is just disappointed he will be neuutered by this election

[Pat]

If you're trying to make black powder, another (possibly safer) option would be to make a potato canon which uses hair spray as a propellant.

If I were making a rock tumbler, I think I would start with a Rotissarie motor for a BBQ. Take the plastic plumbing pipe for the tumbler and put cleanouts (screwed plugs) on each end so you can get it open. Drill a hole in the middle of the end caps and slide the shaft through. Epoxy one end. Load in the rocks. Slide the other end into place and seal with silicone caulk. Then put in the brackets it comes with (even put in the BBQ if need be) and you'll be done.

Maybe something like this:

[HotRod]

I think using plastic or ABS pipe for a rock tumbler may not be the best idea. First I think it would wear pretty fast and second I believe a nice static charge will be generated during the process. For those that have ever sand blasted pieces of steel in a plastic bucket can you say ouch....

[Goedjn]

I wouldn't connect the motor directly to the pipe at all. the easiest thing would be to steal the motor out of a washing machine or something, and just wrap the belt around a pulley on the motor, and around the pipe. Just don't get any fingers caught in the belt. Failing that, replace the pulley with a rubber-tired wheel, and just shove the wheel against the pipe.

How fast is a rock tumbler supposed to turn?

[Bob F]

Not anywhere near as fast as what you propose.

Bob

[David Nebenzahl]

Bob F spake thus:

True that; we're talking about rpms up to the low 2 figures, not 1740 rpm. One possibility that comes to my mind is the small motor in the bottom of a discarded microwave that rotates the platter. I pulled one out recently; runs at about 2-4 rpm or so.