Metal Parts Tumbler Polisher/Rust Remover/Deburring

There are quite a number of homemade parts tumbler designs here, on YouTube, and elsewhere. I want to publish my design, as I feel it has several advantages over some of the others:

• It uses an enclosed direct drive (No belts, pulleys, gears, sprockets, etc)
• Every component (save for the motor) is available at the popular e-shops or local hardware store for dirt cheap
• Gearmotors may take a little hunting to find a used one, but it is worth the effort for the simplicity it brings to the design
• The bucket is easy to put on and take off, or be replaced if it wears out
• The footprint is only 24" x 16", making it easy to store

I am extremely pleased with the result of the build, but more so the quality of the finish I get on my parts.

The components I used include:

• (1) 0.25HP 120V/1PH motor with an output RPM of 60, and a torque of 200in/lbs
• (6) Urethane skateboard wheels with 8mm ID bearings installed
• (6) 8mm Heim joints
• (10) 8mm Locking collars
• (1) 24" length of 5/16" rod
• (1) Jaw coupling assembly
• (2) Iron pipe floor flanges for 1/2" black iron pipe
• (1) 6" length of 1/2" iron pipe
• (1) Plastic 5 gallon bucket w/ lid
• (3) 1 x 2 Wood strips each 12" long
• (1) 24" x 24" x 3/4" Wood board
• (1) 4" x 4" x 12" Wood block
• Miscellaneous bolts, washers, and nuts

If you are not familiar with a "3-Jaw Coupler", allow me to explain. These are an extremely popular item used in all kinds of industries: manufacturing, agriculture, sanitation - pretty much anywhere a motor has to drive a machine there is a coupler involved.

The 3-jaw style is the most popular, as well as the simplest. The hubs (the steel parts) come in every bore size imaginable. It's just a matter of determining what the motor needs and what the driven machine needs. In my case, the motor has a 3/4" shaft w/ keyway so I got that hub.

To drive the bucket, I used 1/2" iron pipe as the shaft, as it neatly fits into a 7/8" bore hub. I went ahead and tack welded mine together for security sake. BE SURE TO LAY A BEAD OF SEALANT UNDER THE FLANGE SCREWED TO THE BUCKET! It will keep the water/soap from running out - ask me how I know.

Between the two hubs lies the rubber spider. The spider acts as a cushion to reduce shock loads from the driven machine back to the motor. The entire assembly is light, maintenance free (I doubt with this I will never wear out the spider) and requires no lubricants.

I chose lumber for the base. I have a 24" square piece of 3/4" thick plywood for the bottom. I cut a length of 4 x 4 and glued/screwed it to the base board. Lastly I screwed the motor to the block. It feels very solid - but time will tell if it all loosens up. I am hoping not, as the jaw coupler is insulating the motor from shock and vibration of the barrel.

Now it is time to mount the wheels to hold the bucket while spinning. I chose 8mm heim joints, which carry a 5/16" shaft that have the wheels and collars on it. The bucket has a slight taper to it from top to bottom so that had to be taken into account.

I connected the bucket to the motor, and shimmed up the other side of the bucket so it was plumb and square to the motor shaft centerline. Next I assembled the rollers. A combination of the standoffs, some locking collars, and the wheels came together nicely - the shaft location, the wheel locations - nothing slides fore or aft. The locking collars position the shaft so the wheels don't rub on the standoffs. I marked where the bolt holes needed to be drilled and bolted the assembly to the board.

Rinse and repeat for the other side. Since I am clueless as to how much load is going to be experienced, I slanted towards the overbuilt side.

I was worried that without paddles, the parts and media would just slide along the wall of the bucket and not tumbled, so I cut (3) pieces of fur strips and screwed them to the sides of the bucket.

The coupler made easy work of dividing the circumference into thirds for accurate placement.

NOTE: Watch where you drill and screw the paddles - you want to be sure they aren't on the same line as the wheels.

PERFORMANCE FOLLOW UP: I've since learned the paddles are unnecessary, the speed of the rotation is plenty to toss everything around effectively.

Time to fire it up and see what happens. I use a bucket lid adapter - it has an outside lip that goes on the mouth of the bucket - then has a screw top to make it much easier to open and close.

I plugged it in, and to my immense satisfaction, it ran true and straight. The bucket didn't walk away from the coupler, it didn't climb up and over the rollers - just hummed right along.

Next I went out to the yard and got about 15lbs of gravel to see how that would go. Same performance - loud as all get out, but it just tumbled along with no straining whatsoever.

The noise was something - in a closed garage it was still quite loud outside, as well as in the house. I measured it at about 75dB at 5 feet - sure seemed louder than that - maybe just more sharp. I certainly can't run it out in the shop - the neighbors would shoot me.

Noise mitigation is a big challenge at this point. My first attempt was to spray a couple layers of vehicle rubberized undercoating inside the bucket. In my opinion, it took some of the hollow ring out of the bucket, and definitely strengthened it some too.

Second thought was to get some acoustic foam panels, glue them inside a box, and cover the tumbler barrel. The box took the edge off of the loudness, dropping the dB to 66. Much, much better.

For the first proof of concept run, I put in some miscellaneous items (tong blank, sphere, washer, painted lift hook) along with 10lbs of HF ceramic tumbling media, and a dash of Simple Green.

Just 30 minutes made quite an improvement, and after an hour the tongs and sphere were perfect. It would take a while to get the paint off the hook - but this was a test anyways - never used a tumbler before.

Took some time to spiff it up a bit with a paint job, and called it a success. I'm going to get a lot of use out of this in my steel art projects.

Thanks for checking this out!