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How to put together a $600+ Vibratory Tumbler for Half the Price

By Dan Imel, Rochester Lapidary Society
From The Rockcollector, Nov. 2012

Ever have that great urge to have a 45-lb. vibratory tumbler? Wince at the $600+ price tag that one of the best units currently on the market, Thumbler's Tumbler, carries? How can you get around that? Harbor Freight carries a vibratory tumbler they rate at 18 lbs. The unit is well engineered and can run a larger barrel. If you look at the reviews, the barrel is too thin for rock tumbling but the unit itself is pretty good. I decided to see what I could do with one of these. If you watch the sales, Harbor Freight frequently has them for sale for $150. Use their 20% off coupon available in most Sunday papers and you now have a large tumbler for only $120. I'd looked at these tumblers for a few years now and was always scared off by the barrels. The solution: Buy the Thumbler's Tumbler barrel. You may have to order the tumbler online if your local Harbor Freight doesn't have them in stock or you don't have one locally. Not to fear, they have a flat rate shipping of no more than $6.99 per order.

Now, time for the modifications first, throw the tumbler barrel away. It's way too thin for rocks. You might save it for the polish stage but, in my experience, it's also so thin that it distorts when you tighten down the hand knob and isn't worth the effort. Mine had holes in it after a little over 200 hours of 80 grit and Harbor Freight doesn't sell replacements. Keep the washers, etc. You'll need to search the web for the Thumbler's Tumbler 45-lb barrel. I found a place that sells them for $180 by the time you add shipping.

Next, even before you use the tumbler the first time, replace the 12-inch, 3/8-inch threaded rod that holds the barrel in place. Why? The threading tolerance is too tight for the grit you'll get on it while tumbling and the hand knob will lock up. Normal bolts and nuts don't have as tight of a tolerance and don't have an issue. It's not pleasant, disassembling the tumbler from underneath with a full barrel of rocks on top you can't remove.

To remove the original rod, with the barrel off, remove the four bolds holding the motor bracket to the plate the barrel sits on. This gives you access to the nut on the underside holding the rod in place. A new 12 inch rod is about $2 at most major home improvement stores. While you are at it, buy two large 3/8 washers and two smaller 3/8-inch washers and place the largest washers closest to the plate the rod passes through on each side and the smaller next to that, add a 3/8-inch lock washer on each side then thread on two 3/8 nuts and tighten, one from each side, and you are done. You'll also need a new hand knob to hold the barrel down. They are available for less than $5 at most wood working stores, 3/8-inch. Cost of all parts should be less than $10 and you may have many of the parts already. I couldn't try the original hand knob from Harbor Freight, since I was never able to get it off the rod. It may work with a different rod. If it threads on or off hard when you get grit on the rod, replace it before it locks up. I'm a wood worker and buy bulk bags of knobs for less than $2 each knob.

Now for that added touch that may be totally unnecessary but doesn't cost anything. Find the lid from a 5-gallon bucket. Dry wall buckets are great. Drill a 3/8 to 1⁄2-inch hole in the center. Place the lid face up between the barrel and the plate the tumbler rests on. I'm figuring that the lid will reduce wear on the part of the barrel that tends to wear out first and its free, so why not?

You'll have to tighten the hand knob down tightly so the barrel doesn't move but this has been true for every vibratory tumbler I've had that's shaped like a donut. I have about 2000 hours on the tumbler so far and it seems to work as well as the $600+ version for roughly half the price. I'm not putting the Thumbler's Tumbler down, they make a very fine product. I'm just providing a more affordable alternative.

45 Pounds too big?

Not into 45-lb. tumblers? Think 18 lbs. would be more than enough? Do the same thing with Harbor freight's 5 lb. tumbler and Thumbler's Tumbler's 18 lb. barrel. Total cost should be about $130.

On the weight differences, the Thumbler's Tumbler's barrels are only slightly larger than their Harbor Freight counterparts. I think the difference is that the Harbor Freight tumblers were designed for polishing shell cases, etc. and, as such, have a lower weight to volume rating than rock tumblers.

For barrels, I recommend The Rock Shed. They seem to have some of the best prices I was able to find online.