Instructables
Picture of DIY Rock Tumbler
My wife recently started making beads and other things from polymer clay, and wasn't getting quite the finish she wanted using sandpaper.  It turns out that even children's toy rock tumblers are relatively expensive and the professional models are definitely out of our price range, so she asked me to see if I could assemble something from old bits and pieces we had laying around.

The kind of tumbler I've seen before seemed like a fairly simple arrangement - some kind of barrel turned by horizontal rollers, similar to a tumble dryer, so that's what I set out to build.


 
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Step 1: Parts List

Parts list - these parts all came from my junk pile. Nothing was purchased for this project, so technically it cost $0 to build. As suggested by several people (iceng and ottwafm), the tumbler would be more durable if some kind of wheel bearings were used for the rollers. Bearings for skate board wheels or ride-on mower decks should be easy to find locally.

1) electric motor from Grand Am electric window lifter.
2) old PC power supply. This one happens to be a 90W supply.
3) rollers - could be broom handle or any round pole. These are actually mini rolling pins from my wife's craft supplies.
4) various bits of wood to make a frame and base board.
5) 2 inches of garden hose.
6) power switch.
7) screws, coach bolts w/ nuts
8) anti-slip shelf liner

Tools required:

1) Saw
2) Screwdriver
3) Drill + appropriate sized bits
4) Wrench
5) Sharp knife
6) Soldering iron (or use crimp-on spade connectors)

Step 2: Initial sizing

Picture of Initial sizing
Initial_Sizing_2.jpg
Cut several length of plank to make the ends of the frame, then stand them in their approximate locations.  The position of the driven roller depends on the size of the motor mount.  The position of the other roller is variable, depending on the size of the drum.  The rollers here are 5" apart on centers.  Later I decided to add a third roller at 3.5" to accomodate smaller drums.
Liam.great9811 months ago
I'm going to try and make a rock tumbler using one of those 120v motors from microwaves that turn at ~30rpm.

I tried that - the problem is that it's so slow that the jar will do two or three revolutions per minute, so it will take forever to polish anything.
What I then did was connecting the motor through a flexible steel shaft to the cover of the jar. It works, but it's not as simple and functional as this one.

ottawafm1 month ago
I agree with iceng. Try using skateboard wheel bearings. Or something similar.
dontremember (author)  ottawafm1 month ago
Yes, some kind of wheel bearings would definitely be a good idea. At the time of building, I had a minimal budget to work with, and was really happy to be able to complete the assembly for $zero outlay. As it happens, the tumbler was used for less than two weeks, and has been gathering dust since. I have updated the parts list to suggest wheel bearings for durability.
arduinoversusevil made it!1 month ago

My free-ninety-nine take on your awesome tumbler!

peach jar rock tumbler.jpg
iceng4 months ago

Running 4 tumblers 24/7. I loose a tumbler with good bearings every few months for some mechanical reason or motor.

Your Ible is well presented and made however wood on wood even with lubrication will not long last.

See if you can modify it to use a bearing for conger life.

dontremember (author)  iceng4 months ago
Thank you for the suggestion. I would probably fit some kind of ball-bearing races if it ever needs upgrading. However, right now it is barely being used at all, and the original dry sockets are holding up OK.
m62558 months ago
Awsome. I have a different use. I have a whole lot of ammunition brass I want to sell but needs to be cleaned. I had a vibratory cleaner that burned out. Then I saw online people using Thumblers Tumbler with number 47 stainless steel pins. It's in water with a few tablespoons of dish soap. The results were better than anything I did with my dry media and vibrator. When I looked to purchase the tumbler they were anywhere from 100 to 250 and up. 5 pounds of pins around 30 bucks. This invention will work wonderfully except I'm worried how the coffee can will hold up with all that brass and pins rolling around in there. Anyone use one of these for this?
agrodolce m62554 months ago

I'm going to make one for jewelry and my husband may use it for his brass. I was looking around on YouTube and saw someone using a big thermos. That's what I'm gonna try. They're pretty thick so I think it'll be fine.

dontremember (author)  m62558 months ago

You could equally well use something like a paint can, those generally fit tight enough to need a mallet to close. Any tube with a screw top would work too - a strip of duct tape would help stop it unscrewing. Once you find an appropriate container, you can size the frame to fit. Also, you'll want to pick a motor that can drive the weight without running too hot, and make sure the rollers don't bind. You could even pick up some cheap ball bearing races for the rollers.

excellent project. I only suggest (unless another beat me to it) you can coat the rollers with silicone rubber in a tube (if you have left over from something else), or even several coats of rubber cement or rubber inner tube sleeves..

but use wut ya got!

verra nice indeed
dontremember (author)  spark master2 years ago
Thank you! As it happens, we had a couple of yards of rubber shelf liner available, so that's what was used.
what do you put in it to polish the beads?
dontremember (author)  spark master2 years ago
My wife has tried a number of different things, from play sand slurry down to small dry squares of fine sand paper and denim. I'm not sure which produced the best results. I suppose it depends partly on how smooth the beads are to start with.
well done thanks
gloflyer2 years ago
Totally awesome job. I have a VERY expensive rock tumbler, but needed an extra barrel. I tried the folger's coffee can, but it did not turn reliable. Now I will try adding the shelf liner. It was a big DUH when i saw what you did.

A few tips: Normally you would use tumbling grit instead of sand. I am going to assume that the beads are already reasonably shaped, you just want to add a polish, so a finer grit or even a polish should work fine.

There is way too much sand. Depending on the size of container, back it off to a few tablespoons of grit, and then fill it up about 1/2 way with water.

You do not need any vanes. If you get the slurry to the right consistency, it will slide as needed on its own.

Good luck and let us know how it works.

P.S. A lot of folks use a thin coat of Future floor wax on the beads, and then bake them gently in a low oven.

dontremember (author)  gloflyer2 years ago
Thanks!! I give my wife credit for the shelf liner - I thought maybe just wrapping the rollers would work, but she went ahead and wrapped the barrel too, which works substantially better.
ichibon2 years ago
this is such an awesome project. i will inddeed give it a go. 5/5 from moi.

rimar20002 years ago
Very good work!

Yes, to add vanes is a need. But it is an easy task, now.
dontremember (author)  rimar20002 years ago
Thank you!

We probably won't use the glass jar much. The big red tub in some of the photos is a coffee can with a built-in grip that functions very nicely as a vane. Also, being plastic, I can easily screw through it to add vanes as necessary.