Rotary Tumbler Design

[gzig5]

Looking for suggestions. I'm thinking about building a rotary tumbler like the Thumbler's model B that would hold 10-15 pounds of material. The Thumbler's sell for about $200 shipped which isn't horrible, but it isn't free either. The frame and drive are no problem and I have appropriate motors. I'm struggling with the drum design which is typically faceted and includes a molded rubber liner that seals water tight when the lid is clamped on. I can bend up and weld a drum, but what to do about the liner which looks something like the one in this pic and sells for $55?

http://www.provision-resources.com/s...12Tliner-w.jpg

I'll mainly be tumbling brass rifle cartridges with little stainless steel rods as media in a soap solution, so it needs to be water tight. I think the rubber liner is there for reducing noise and the think could be made to work without it, but it would be loud. The HF ones I have seen are too small.
Greg

[ulav8r]

Years ago I bought a roll of rubber-like gasket material to line a blast cabinet. It would also make a good liner for a tumbler. It was about .1 thick.

[ZINOM]

Might sound stupid but don't some places spray on undercoat (for cars)?...that might be an option...no?

Or some of the spray can stuff from places like Eastwood.

Probably not worth the 2 cents I put in actually

John

[Bruce Griffing]

I am just brainstorming, but wouldn't spray truck bed liner be a good choice?

[Cobbler]

I built a rotary tumbler using a treadmill as the basis for the design. For the barrel I used 8" PVC with some plastic ends I turned on the lathe. Mine has 3 plastic paddles made from some 1"x1" angle screwed to the inside of the barrel. There are photos and some discussion of the project here...

http://garagegunsmithing.com/forum/v...php?f=31&t=542

I would bet with just a slight re-design of the through bolt and an O-ring on each end cap and it would be reasonably water tight.

Why do you tumble them wet? Everyone I know uses either ground walnut shells or ground corn cobs.

[dp]

Get a large PVC 4-way cross connector, put 6" stub pipes on each connection (forming a big "X"), fill with your work, abrasive and fluids, cap with threaded caps, spin slowly for a while.

One of the strangest tumblers I've seen is a car tire mounted on a rim and attached to a spindle with motor. The tire had been drilled on the sidewall and a pvc cap attached somehow to allow access. Obviously not pressurized. The stuff would go in there and the tire would rotate at a slow speed for as long as it took. It was large, but dead quiet, and had huge capacity. I might consider a tire from a utility trailer.

Image of a cross connector:

http://www.littlegreenhouse.com/accessory/p-cross.jpg

[Boucher]

Would a small cement mixer work?
http://www.harborfreight.com/power-tools/mixers.html

[gzig5]

Why do you tumble them wet? Everyone I know uses either ground walnut shells or ground corn cobs.

That's what I used to do when I started, then I went to ultra sonic which works great but needs small batches, and now this. The brass comes out looking like new, no matter how dirty inside and out. Media doesn't stick in flash holes. The water solutions carries away the junk and help cut the carbon.

http://www.ar15.com/forums/topic.html?b=6&f=42&t=311325

There are a few sources for the media which costs about $10/lb delivered. Expensive, but will last a lifetime or two.


The big PVC pipe will work if I can find a short section for a reasonable price. If I have to pay $50+ for material for the drum I might as well go whole hog and get the Thumbler's.

[gzig5]

Would a small cement mixer work?
http://www.harborfreight.com/power-tools/mixers.html

Yes, it would and there are high volume guys that use them, but it is about 10,000% too big for my needs. I'm talking about a drum 8-10" in diameter and about as tall.

[Highpower]

Would a small cement mixer work?
http://www.harborfreight.com/power-tools/mixers.html

FWIW... Sierra Bullets uses small cement mixers sprayed with the truck bed liner material inside. They use ground corncob though for the final polishing on their bullets.

I'm a bit leery of using the little stainless "needle bearings" myself. Impacting my cases with steel sounds like a good way to work harden the brass. I can't prove that of course.
I do use a RCBS Sidewinder tumbler with similar drums for doing my moly coating though. Holds 10 - 15 lbs of bullets & stainless balls with no problem.