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Broken belts using tumbler

I purchased a Chicago dual drum rotary tumbler from Harbour Freight
to tumble rocks. I started using it with pieces of quartz up to 1"
longest direction, course grit and water according to the
directions. After 2 days, the belt broke, Harbour Freight gave me a
new belt which also lasted about 2 days. I looked at home improvement
stores for a suitable replacement belt without success so I went back
to Harbour Freight and they replaced the whole machine, saying there
must be a problem, these belts don’t usually break like that. I’ve
been using the new machine since Monday afternoon and this afternoon
(Wed.) the belt broke. I know ‘you get what you pay for’ but now I’m
worried I’m doing something wrong. Does anyone else use these
tumblers successfully? Does anyone have any suggestions for belts
that will not break after 2 days? They appear to be a smooth rubber
’V’ belt.

Thank you, jeanette

People either love or hate the Chicago rotary tumblers. I’ve had
excellent use from two for several years. In many cases, when someone
has reported belts repeatedly breaking, I’ve found they have not read
the maintenance section in the users’ manual which says “Before the
first use, and once a month following, put a few drops of oil on the
Driving Shaft Set (#12) bearings. Check the Belt (#37) tension. It
must be kept as loose as possible without allowing it to slip on the
Driving Pulley (#35). Check before each use.” Both of my tumblers had
the belts entirely too tight when taken from the box. I’ve made it a
habit to check every couple of months and haven’t had to replace the
belt(s) (touch wood LOL)



You aren’t doing anything wrong. It’s just that the Chicago Electric
tumbler sold by Harbor Freight is notorious for breaking belts. I’ve
heard the same experience you are having from many purchasers of this
tumbler. A couple ideas. I recently saw Chicago Electric tumbler
belts on eBay for a reasonable price or I’ve also heard a sewing
machine store is a good place to buy a replacement belt that lasts.

I don’t know if it is a design flaw of the tumbler which I have heard
there are a couple or if it’s the belts that are flawed. Either way
Harbor Freight has got to be losing money on these tumblers with all
the returns and complaints.

The good news is that the barrels on the Chicago Electric tumbler are
pretty good and will fit more reliable makes of tumblers like
Thumlers or Lortone. If you want to invest in a better tumbler it is
always desirable to have extra tumblers so you can use one grade
grit per barrel and don’t have to worry about cross contamination. Or
if you happen to see a used one on eBay or at a garage sale sans
barrels you are all set.

I don’t mean to dog Harbor Freight or Chicago Electric. There are
some tools that are OK but some things that are pure junk and a waste
of money.

I will add that Harbor Freight came to my rescue yesterday. I cut and
sell lots of cabs. I shape them on an 80 grit then 280 grit diamond
wheel. Then put them in a vibratory tumbler with 150/220 grit for 1
or 2 days. Then 600 grit for one or two days. Then into a separate
vibe tumbler for polishing. Not only does this speed up the process
but I get a nicer polish this way. Anyway, yesterday morning I got a
rude surprise. One of my vibe tumblers wore through the bowl spilling
slimy tumbling slurry all over the place. Without one of my tumblers
my cab production comes to a complete stop. So after querying my
usual supplier about upgrading the next size bowl and having them
ignore my emails. I won’t mention their name because they have been
very responsive to my complaints about crappy service. Too late. They
are on the bottom of my list of preferred lapidary suppliers. So in
desperation I looked at the Harbor Freight site because they sell,
you guessed it, Chicago Electric vibratory tumblers. And much to my
pleasant surprise they sold replacement bowls and my local Harbor
Freight store had them in stock. The harbor freight bowl was $12.95
where a replacement bowl for my vibe tumbler was going to run me $75.
After seeing the bowl and how it fit right on my vibe motor I was
sold on them. Bowls for vibe tumblers wear out from the abrasives and
the Harbor Freight bowl will probably not last as long as the $75
replacement but I can buy 6 harbor freight bowls at the same price. I
need to go back to Harbor Freight and buy the two other replacement
bowls they have in stock for spares. Before word gets out and there
is a run on the store because I am such a blabber poster when I find
a solution or product that really works for me.

Rick Copeland
Silversmith and Lapidary Artisan
Rocky Mountain Wonders
Colorado Springs, Colorado

Jeanette. No you are not doing anything wrong except perhaps
overloading the machine. These machines are made primarily for
cleaning shell casings for reloading ammunition and are only run for
a few hours at a time. They do not wear well to tumble stones and run
for long periods. Belts break often!!!

Keep looking, perhaps a vacuum sweeper belt if you can get a proper
size. Good luck and cheers from Don in SOFL.

I know 'you get what you pay for' but now I'm worried I'm doing
something wrong. Does anyone else use these tumblers successfully?
Does anyone have any suggestions for belts that will not break
after 2 days? They appear to be a smooth rubber 'V' belt.

I’ve been using mine for three years and still haven’t broken a belt
but I did do the belt adjustment mentioned in the manual before I
started using it. The only other reason for the belt breaking that I
can think of would be overloading the barrels.



Just be aware that with the replacement HF bowl, you need to make
sure you ONLY run it with the lid securely bolted on. Otherwise, the
plastic will warp and distort very quickly. Not sure what it is with
that particular bowl, but I’ve had it happen! I prefer to run my
green buff in the vibratory with the lid off for a while as I’m
adding pieces, but I can’t do that with that bowl. The lid seems to
be what keeps the structural integrity of the bowl. Ah well.



That particular machine is kind of notorious for its belt issues. We
have one in our shop at school and it’s driven us nuts since we got
it. The one thing we’ve found that works for the belt replacement is
the metal-free elastic ponytail holders… the thick ones. They come
in a variety of diameters, and the largest is just about perfect in
tension and size to drive the thing. Now we keep a bag handy for
whenever we need one.

Hope this helps!
Karen Goeller
No Limitations Designs
Hand-made, one-of-a-kind jewelry

Thank you one and all. I think my problem was the belt tension. I am
used to car, typewriter and other belts that need a tighter tension.
I loosened the tension until the belt slipped, then tightened it
until it just didn’t slip and haven’t broken the belt yet. I don’t
think I over filled the barrels used about 1 lb of stones so with
grit and water, total barrel was under 3 lbs.

I have purchased a single barrel Chicago tumber and the belt for
that one is a round rather than a ‘V’ belt but it also broke before
I realized the tension was too tight. I have ordered Lortone belts
that are advertised to be used on the HF’s dual drum tumbler.
Meanwhile I found a Hoover vacuum belt that was too wide so I cut it
into 3 strips (just with scissors real sloppy job) but it has been
running longer than anything else with this looser tension.


Hello Jeanette,

In addition to Dorothy’s comments about checking the tightness of
the belt and lubricating the motor shaft, also make sure that the
finned wheel is adjusted so that it does not brush against the
housing. Once I moved the wheel ever so slightly, the HF tumbler has
been rolling along for quite some time. I did order extra belts from
HF, but will check out an O-ring store next time.

Judy in Kansas, where the last two days have been so lovely! Got the
forsythia branches inside to force.