Hobby or Case Tumbler

My inspiration for building this tumbler was to build a brass casing cleaner; however it can be used to clean and polish everything from brass to sparkplugs and stones. I built it out of easy to get materials and parts that satisfy the three R’s of environmentalism, reduce, reuse and recycle. The two 1 kilogram coffee cans came from my own recycling bin, the two-speed motor, power cord and the switch came from an old electric heater. The nuts and bolts came from my local hardware store and three internal parts I made from a plastic-cooking spoon. Almost all of the parts came from the garbage except the nuts bolts and washers. The total cost to me was under five dollars and one day to build. Tumblers the size of this one can cost up to three hundred dollars to buy in stores, so the tumbler is not only environmentally friendly it is also economically friendly as long as you can afford a day to build.

I started with two coffee cans of the same size I retrieved from my recycling bin. Any container that is solid and has a lid can be used to make the tumbling chamber or the base. Tin or thick plastic will do best for mounting screws and bolts.

One can I drilled five holes (the tumbler chamber). I saved the plastic lids of the coffee cans to use later as a protective base and as the lid of the tumbler chamber. Three of the holes I drilled ½ inch in from the outer edge to mount the suppression mounts. The two holes I drilled for the motor mounts were strategically located by placing the motor on the bottom of the tumbler chamber locating the shaft of the motor in the center of the chamber. Then I marked the hole placement with an ice pick.

For the base I cut the bottom out of this coffee container with a can opener. Weather tin or plastic be sure the base is solid enough to support the finished product. This can be done by placing a five-pound weight on the top of the base and gently shaking, if it collapses it is not strong enough.

I made the spacers to mount the motor out of an old plastic-cooking spoon. Just about any thing can be used as spacers as long as they are square at the ends with a hole in the center and fit the available space for mounting the motor.

I mounted the cooking spoon in the chuck of my drill press and the drill bit in the vice mounted to the base of the drill press. This acted as if the drill press was a lath, boring through the center of the plastic perfectly. I cut off the desired length of the motor mount with a hacksaw blade while the drill chuck was spinning. This made the cutoffs square for a tight mount to the tumbler chamber.

Then it was a simple mater of bolting the motor and mounts with two bolts, washers and two nuts. When the motor is mounted to the tumbler chamber the next step is to attach and adjust the counterweight. The counterweight is made the same manner as the motor mounts after the center of the counter weight is drilled out for a bolt you drill at one end a 90% angle a hole the same size as the motor shaft. In one end there is a screw to hold the counterweight tight to the shaft at the other there is the bolt. The amount of vibration can be adjusted by moving the counterweight along the motor shaft or unscrewing the bolt to expand the center of gravity of the counterweight.

When the counterweight is complete the tumbler chamber can be connected to the base. The connection between the two needs to be flexible I did this with springs to create the suppression mounts. The suppression mounts allow the tumbler chamber to vibrate without transferring the energy from the tumbler chamber to the base. To do this I mounted three L. brackets on the base with rivets. The L. brackets were located with the holes in the brackets in corresponding locations with the holes in the tumbling chamber. After the L. brackets are in place I put a washer on a long bolt and put the bolt in one of the holes ½ inch from the rim. With the bolt passing through the bottom of the tumbling chamber I added a washer to the outside of the chamber. On top of the washer I added two nuts to the bolt and tightened them, the second of the two nuts act as a locking nut stopping the nuts from undoing from the vibration. I repeated this for the other two holes.

When all three bolts are in place I add a washer and a spring to each bolt and placed the base on top of the springs by holes in the L. brackets. With the base in place I added a spring, washer and two nuts. The two nuts are tightened against each other to lock them so that the vibration will not cause the nuts to loosen. As shown in the color-coded diagram above there isn’t a solid connection between the tumbler chamber and the base. Without a solid connection all the energy created by the motor is transferred to the tumbler chamber.

With the two halves joined the next thing to do is mount the switch to the side of the base, this is done by drilling a hole in the side of the base and screwing the switch to the side of the base. Once the switch is installed you drill a hole in the other side of the base for the power cord. You put the power cord through the hole and connect the wires. The green wire from the power cord is connected to the base, the white and the black wire is connected to the switch. Since the motor I used is a two-speed motor, all three wires from the motor are connected to the switch. If you were to use a single speed motor the motor would only have two wires, one would go to the switch and one would go to the white wire on the power cord depending on the switch. With the wires connected you tie the wires down to the inside of the base to keep them from getting tangled in the counter weight with that done you secure the power cord with a collar or a grommet.

Different materials will require different polishing media.
The last thing to do is to put one plastic lid on the bottom to protect your table or work bench, load your tumbling media into the tumbler chamber put the lid on the tumbler chamber, plug in the tumbler, turn it on and start tumbling. Depending on the material to be tumbled the media can consist of crushed nuts to crushed glass with polishing compound. Brass products are polished with crushed corncob and polishing compound. Steel products are polished with crushed glass and a coarse polishing compound. The different materials are tumbled for different time periods. So have fun with your new environmentally friendly tumbler.