My $50 lathe mounted brass tumbler, with pics

[Andy]

I have been reading around on DIY tumblers and have stolen many good ideas for this project from posts on this and other forums. I think the only unique thing I am adding to the equation here is the idea to mount it right on my lathe, to reduce cost and keep the thing dirt simple. This couldn't have taken me over an hour and a half to make and test once I had the parts on hand.

Uses a dowel chucked onto the lathe as the drive roller, two casters on a piece of plywood as the dead rollers. 6" pvc pipe with an end cap and 6>4 reducer, fernco as the seal. Clamps hold the plywood to the lathe bed and another clamp holds an outrigger to keep the pvc end cap from riding into the lathe head and creating drag. Lathe is set to 400 rpm, it's lowest setting, and the dowel was turned on the lathe to the appropriate size to give me 60-70 rpm and to ensure it was centered.

You can calculate out the dowel size you need based on your cylinder size and your lathe lowest speed. For me, I would have liked to do a 1/2" dowel to get 30 rpm (and then adjust higher with the variable speed control), but 1/2" seemed to small to nicely span the gap. If I decide to tune it down I'll use a 1/2" metal bar or a 3/8" bar with some grip tape on it.

Holds 1.3 gallons by volume. Right now I have 5 lbs of media in there. Did a test batch of 50 cases and they were done in an hour. Currently doing about 300 cases and we'll see how long that takes. This lathe has a quality 1/2 hp motor so I'm sure I can max load it with whatever will tumble correctly and not worry about the motor. The equivalent thumler has a 1/30hp motor, for example.

Total investment:
pvc pipe: free scrounge
end cap, 6>4 reducer and fernco: ~$30
Three decent casters: $20

I already owned the casters but also had to buy the 5lbs of media, so I'm out of pocket less than $60 total on this thing.

I just built this tonight so once I have the kinks worked out I'll make a nicer bottom plate that incorporates the outrigger built into it, and fine-tune the caster line-up and then install wood blocks on the underside of the bottom plate to guide off the lathe bed and make it easy to remount in exactly the same spot every time. Also might put some grip tape on the dowel where it rides on the pvc. It is working 100% right now but I can see the wood starting to gloss up and I imagine that will lead to slipping at some point.

I can hear it running the basement right now. With the 50 rounds you couldn't even notice it, with the current batch of 300 it sounds about like a treadmill running in another room.

Hope you enjoy reading about the design, if you have a lathe and need a wet tumbler try this out. It was dirt simple.

Andy

[Andy]

Sorry for not having larger pics, I compressed them on my computer but I think the site did it again for me (first time posting pics here). If anyone wants larger photos just let me know. I also have a video or two showing other angles and the thing running.

[VHoward]

Cool!

[SSGOldfart]

I like it but Grem460 also uses his lathe for a tumbler

[dikman]

You didn't mention whether you have fitted any (longitudinal) baffles. If not, I suggest fitting some as it works a lot better with them (my experience here).

[Andy]

Yeah, I used (2) 1/3 circumference sections of 2" pvc for the baffles inside. I didn't know the right term for them.

Drats! I hoped I was the first one to think of this lathe idea but I did come up with it on my own at least.

Ran that batch of 300 for about 2 hours, they were clean except that the primer pockets were only about 90% clean, so if I want them perfect I would probably need to run it a little longer or put some more media in.

[LUBEDUDE]

Cool Beans!

[VHoward]

Absolutely nothing wrong in using tools you already have to accomplish a task. Just because you didn't think of it first makes no difference.

[RickF]

Cool stuff, since I don't have a lathe and having a wet tumbler is on my to do list … you have me wondering if I might somehow be able to use my drill press to build one.

[bbqncigars]

Nice. I wish I'd thought to repurpose my wood lathe like that. Oh well, the Thumler still does a good job.

[customcutter]

I bought a small HF concrete mixer, and it works great. Didn't even have to invest in SS pins.

The lathe idea is very cool though.

[Andy]

For what it is worth, this is the jet variable speed mini lathe (often bench mounted and looks much smaller than this usually). I have the full stand with extension and the bed extension so it looks somewhat like a full size lathe, but it is still about the smallest commercial/semi-pro lathe you could buy. Why I'm mentioning this is that if an outdated lathe shows up at a garage sale it probably has an equivalent motor to what I am running. Many lesser brand/outdated mini lathes would work well for this, and sometimes don't go for much used because their tool rests and/or beds/chucks are not up to the standard for doing good woodworking so there isn't much demand for them. As a case in point I saw an older craftsman entry level wood lathe a year ago that could have been fairly had for $50 that was a mediocre lathe, but would have done this job very well. Worth considering if you find a great deal on a used lathe, or have cause to want a wood lathe as well as a tumbler, and have neither at the moment.

I see those shopsmith tools for sale on craigslist all the time, I'm sure there is a way to run something like this off one of those if you have one.

This doesn't see to be too picky about the bottom plate mounting angle. Something about however I set up the casters, or the tube itself seems to always drive it toward my outrigger roller, so it seems like I really can't mess up the mounting if it is within eyesight of square to the bed. Wanted to mention that in case anyone wondered if it was a hassle to set up/take down. I've had the thing on/off a few times and it is less than a minute even if something doesn't go right with the clamps.

[NavyVet1959]

Or, if you think that you need a bit of exercise, then do a pedal powered brass tumbler. Something like this design (which is for washing clothes), perhaps?

[jmorris]

Reminds me of my "no cost" case trimmer (if we are counting on equipment we already have).

[smoked turkey]

Say Andy that is a very good idea. I thought sometime I would cobble something together in order to try wet tumbling. I think you have given me a wonderful idea. My wood lathe does not have variable speed so don't know how it will work but if I can work out the RPMs I think I will give it a try. Thanks for the cool idea.

[Andy]

One thought if you are making one of these: the 4" fernco is a bear to get on the reduced pvc (5" o.d.) and the 5" fernco is somewhat hard to come by/more expensive. I had to heat mine in hot water to get it on then leave it for a few days to conform to the stretched shape. Now, I can just barely get it on by hand, so probably worth finding the 5" fernco if you are doing this method. I wouldn't go any smaller on the reduced size since I imagine you want to be able to get a hand in there.