Tumbler suppliers Kingsley North http://www.kingsleynorth.com/tumblersr.html has both types. For the rotary Lortone Model 3A is the most popular for most of us and the price for it is $58.00. The vibrating one http://www.kingsleynorth.com/tumblersv.html that has a 4 lb capacity is $85.00 and the model is 9-1059 They also have mixed stainless steel shot at $16.00 a lb. http://www.kingsleynorth.com/mediametal.html
Harbor Freight Tools http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=46376 has a 3 lb tumbler for $28.00 and I believe several people have then on our forum. I don't know if they will hold up at all but if you want one and don't have the money for one of the others this might be the way to get you started. You will see they also have a tumbling media that costs only $7.99. It doesn't say anything about it so I am sure it is not stainless and will require special care to keep it from rusting. It is not worth the trouble. Get stainless steel!
Lortone http://www.lortone.com/tumblers.html has tumblers also but they are $62.00 for the 3lb size.
Dads Rock Shop http://www.dadsrockshop.com/tumbler_rotary.html Has the 3lb size for $57.95 and he has a 4 lb on for $ 78.95 that looks interesting like it might work well for larger pieces but will not be so big as to have to have a lot of shot. His shot is $17.50 lb http://www.dadsrockshop.com/tumbler_metalfinish.html and doesn't have pins in it.
Ok you get the picture. It seems that the retail on most sites is $62.00 for the Lortone tumbler. Also some people are using reloading type tumblers used to polish the casing for bullets. Some of those are not used with water so you have to be careful when you buy they that they are sealed for wet tumbling. Do a search on Google and you will get a lot of places to look. Just be sure you get Stainless Steel shot. It is easy to take care of.
Now down to the mechanics of the whole thing. First you need to scrub out the tub that comes with the tumbler with soda paste and a toothbrush. The rubber usually has a coating or the rubber itself from the molding sometimes will cause the first tumbling to turn the water black and has caused some people problems by turning their jewelry gray. It is just a coating on the jewelry but has to be done over so may as well do the scrubbing first and get it over with.
Tumbling Not put the shot in. It should come up into the tumbler about a � or 1/3 of the tumbler. (Mine is only an inch deep and it works fine I only have one lb of shot in mine) That is what most people say. I will leave this open for you to decide. Maybe talk to other. Some say 2 lbs. That leaves a lb for you to put in jewelry.
Some people will put in plastic pellets to soften the tumbling. I thought I would try that and bought a bunch of plastic pony beads. Not the ones that are coated with paint but the ones that have the color all the way through them. I used them and then I took them out. I can't tell the difference. So I don't use them now.
Now put in your jewelry. If you are putting in components like jump rings you can string them on a wire so they are easy to remove. Some chains need that too if they have thing hanging that you can string into. It does help with tangling. And rings also. If you have a lot of rings just string them on a wire loosely and they will still tumble nicely but you will be able to get them out easily.
Cover the whole mess with water about an inch over the top of the jewelry and shot. Drop a couple of drops of Dawn dish liquid in and set it on the tumbler. For some reason my tumbler doesn't like to start turning right to start with. I have found that if I leave it off the little v shaped holder that is supposed to hold the knob that you tighten on the lid, that it will turn better. It is funny because it tells you to put in so that holds the tub in place but it doesn't work for me so if you have problems with it starting to turn you might try that. I never use it any more.
Timing Now you let tumble for about an hour and then look at something in it to see how it is coming along. If you are tumbling just to polish you won't need to leave it as long as if you want to harden something up. So these are things you have to learn as you go a long. But start with an hour and look and see how it is doing. Sliver can be tumbled all nite if you want but I never do. Gold filled should not be tumbled so long because it is after all a layer of gold and tumbling does remove some material each time. But I tumble it for an hour or so and that is usually enough.
Maintenance The tumbler will need to oiled once in a while. Here where it is sandy and the air is dry it seems to be oiled often. I use 3 in 1 oil and oil the rods that the tub sits on at the ends of each one. I will oil and then wipe off and oil again because it usually looks black and so I just wipe it.
Now there are some stones that you shouldn't tumble. Any soft stone or anything that is coated or beads that are lined with color shouldn't be tumbled. Amber, Azurite, Malachite, Rhodochrocite, some Turquoise and Varisite, and probably others, are all soft. If the polish on the stone is not glassy and hard looking chances are the finish will come off with tumbling. Turquoise and Varisite are sometimes treated and are hard enough to handle the tumbling. Some people have said they have tumbled pearls for short times too with out problems. If in doubt don't tumble or if you have beads just tumble one to see. It is all a learning process. And Beads and stones that are the same rock but from different sources will be different so you can't say just because it is Lapis it will tumble fine.
The rocks that we use are all made up of different minerals and if there is more of one mineral that is soft, in one location when the rock was formed it could be softer than if it were formed in a different location where the minerals that went into forming it were of a harder nature. None of the stones we use are of a pure nature. That is what makes them so interesting and beautiful.