Thumler's Tumbler Model B Drive Belt Life - Poor

[9.3X62AL]

Hi, 9.3x62AL -

You're absolutely spot on about those Thumler's - they're designed to run for weeks on end. So, I was taken aback why my belts were breaking. To this day, I don't know what was the cause, and I've addressed about everything. Like you say, could be the humidity factor. I was given clues, though, about when a factory belt was about to fail - these belts are nearly transparent and little fractures would show up. When those showed up, the belt was only hours away from failure. And I went through quite a few of them.

Oh well, at least the ethylene-propylene o-rings are about 7 times cheaper and seem to last much longer, for me at least.

Happy Tumbling -

Bayou52

Just weird. Maybe Thumler's got a bad lot of drive belts that you got a large helping of. I imagine the company uses a vendor/sub-contractor to make/provide the belts to their specs, and you got the short end of the stick.

[Bayou52]

Just weird. Maybe Thumler's got a bad lot of drive belts that you got a large helping of. I imagine the company uses a vendor/sub-contractor to make/provide the belts to their specs, and you got the short end of the stick.

I was thinking the same thing, 9.3x62AL - bad belts to begin with.

Just curious - your belts seem to be working fine. Are they transparent when you look at them, or do they have a solid color? The newer ones I was using were transparent.

Thanks....

[9.3X62AL]

My OEM belts have always been transparent, and have a definite joint showing.

[ak_milsurp]

What about a belt replacment idea for the smaller thumblers tumbler AR-2? I mostly use vibratory tumblers, but reserve my ancient AR 2 for small batches

[fastfire]

As Montana said, tension maybe to tight?

I use 5lbs ss media fill Full of brass, fill to the top with hot water, Lemi shine and Joy soap.
Once in a while I'll have to reduce the weight but as long as it turns it's a go.
Run for 30-40 min each batch. The more SS you use the less time it takes.
Replaced the belt once in 6 years of use.

[mold maker]

My original Thumblers is from the 80s and I just re-placed the belt and drive axle this Winter. it only saw about a year of rest, and upon reuse the belt broke immediately. I tried a vacuum belt and it seemed too tight, causing the large pulley to release from the shaft.
The new axle and OE belt have around 225 hr on them now with no problem.
No idea why the original belt lasted so long other than regular use. When it finally broke it fell into many pieces.

[Bayou52]

I'm amazed to hear that y'all are getting such good belt life out of your Thumler's belts. Definitely better than my experience, for sure.

One theme I'm hearing as a posdible cause of poor Thumler's belt life is that the belt might be too tight. Yet the Thumler's model B has no adjustment for belt tension. The motor simply is bolted in place, and the drive axle bushings simply snap into their slots. Nothing to adjust.

So, without a way to adjust tension, how can you check if the belt might be too tight?

Thanks for the ideas, fellas...

Bayou52

[340six]

I'm amazed to hear that y'all are getting such good belt life out of your Thumler's belts. Definitely better than my experience, for sure.

One theme I'm hearing as a posdible cause of poor Thumler's belt life is that the belt might be too tight. Yet the Thumler's model B has no adjustment for belt tension. The motor simply is bolted in place, and the drive axle bushings simply snap into their slots. Nothing to adjust.

So, without a way to adjust tension, how can you check if the belt might be too tight?

Thanks for the ideas, fellas...

Bayou52

For a rubber O ring I have always gone to
Tiger Seal & Gasket Manufacturing Co., Inc. {LSU GUY}

2522 Connecticut Ave Kenner, Louisiana 70062

(888) 875-5125 It is close to me and just do it as a walk in. They can also make anything ya want while ya wait. Or at least did for me.

I just got a Model B sent to me from Cabela's and the pulley on the shaft spins and goes back and forth. Like the pulley is pressed on crooked / bent
So as the motor turns it it wobbles back and forth. This is not just the shaft going back and forth as it should be inside the while bushings.
So I called them and they sent another and the same thing. It turns and rotates the pulley moves back and forth. Not just the shaft but the pulley itself wobbles. Like the pulley was bent when pressed on the shaft. {ie} not a bent shaft. Is your pulley like this?
Or This happen to anyone else?

[Bayou52]

For a rubber O ring I have always gone to
Tiger Seal & Gasket Manufacturing Co., Inc. {LSU GUY}

2522 Connecticut Ave Kenner, Louisiana 70062

(888) 875-5125 It is close to me and just do it as a walk in. They can also make anything ya want while ya wait. Or at least did for me.

I just got a Model B sent to me from Cabela's and the pulley on the shaft spins and goes back and forth. Like the pulley is pressed on crooked / bent
So as the motor turns it it wobbles back and forth. This is not just the shaft going back and forth as it should be inside the while bushings.
So I called them and they sent another and the same thing. It turns and rotates the pulley moves back and forth. Not just the shaft but the pulley itself wobbles. Like the pulley was bent when pressed on the shaft. {ie} not a bent shaft. Is your pulley like this?
Or This happen to anyone else?

Hi, 340six -

Thanks for the info on Tiger Seal. Even though I'm in Slidell, I was unaware of them. Always happy to support local businesses.

I'm still on my first o-ring - it's lasted over a year now - much longer than those factory belts.

About your issue with the drive shaft pulley being off center and wobbling, I know the exact issue, as I had the same thing. Like you, I called the office and got a replacement. The replacement shaft and pulley were true - no wobbles. So, that solved the problem for me. In your case, I would call again and discuss the issue. I would also offer to send back both drive shafts once you get a true one and if they send you a postage paid box. They may not want the old ones back, but at least you've taken the high ground with the offer. I do recall them being very cooperative with no questions asked.

Also, once you get a true drive shaft, you might want to check the channel on the drive shaft pulley - mine had little burs in it left over from the casting mold. A couple of passes with a rat-tailed file smoothed the channel nicely. The burs could damage the belt/o-ring.

So, after getting some initial bugs worked out, my Thumlers model B spins smoothly with no sway, wobbles or hitches. I really enjoy using it and wet tumbling brass.

Let me know how you make out.

Bayou52

[EDG]

I have the AR-12 Thumbler's Tumbler - the one with the 12 lb rubber drum
I bought it in 1970 and promptly ran all my brass through it including 1000 nasty SL-54 machine gun fired 30-06 cases.
I bought 2 extra belts for it. They are still stored in the tool chest and I am still running the original belt.

[mold maker]

My first TT was well used before I acquired it. The drive shaft and brgs were sloppy and still had the original belt as far as I could tell. After another several years, the pulley loosened on the shaft, and all attempts to repair failed. A new set of shafts and spare brgs put it back in service and I expect it to serve me for a long time. The original pulley was metal, and the new ones are molded plastic.

[Catch]

When I first purchased my tumbler, I noticed that the motor had a slight vibration up and down on the non belt end. As it progressed in the cycle it seemed to get worse now and then and I turned it off and made an L shaped piece of aluminum which I attached to the floor of the unit and to the bottom nut on the bolt that holds the motor together. This gave the motor a brace on each end and seemed to cure the small vibration. I have never had a problem with the belt that came with the unit, but you might try the added brace on the opposite end of the motor and see if your belt last longer then. Hope this helps...........Catch

[powderburnerr]

I do not put a gallon of water in mine ,the water level is just below or barely above the level of the media , and I do about 100 long 45 cases with 50 or so smaller cases thrown in ,havent broken a belt in 10 years of solid use , ,once in a while I give it a shot of spray oil on the shafts when they squeek. 2.5 to 3 hir=urs and lots of clean cases come out of some really black water.

[Nueces]

I've got more than 5 years on my first belt on the Thumler Model B. I dealt with the motor vibes by putting a piece of foam pipe insulation under the free end of the motor casing. I also adjusted the position of the motor pulley so that it was parallel to the driven pulley at the center of it's side to side wandering. An occasional drop of CLP for the plastic shaft bearings.

Now and then, I run an over weight barrel. I monitored motor running temperature with my hand and was surprised to find no significant heat buildup. Bloomin' thing is like the Energizer bunny.

The newer lid gaskets appear to be some sort of vinyl rather than the rubber I got originally. The vinyl seals better and doesn't curl up around the edge.

[Bayou52]

When I first purchased my tumbler, I noticed that the motor had a slight vibration up and down on the non belt end. As it progressed in the cycle it seemed to get worse now and then and I turned it off and made an L shaped piece of aluminum which I attached to the floor of the unit and to the bottom nut on the bolt that holds the motor together. This gave the motor a brace on each end and seemed to cure the small vibration. I have never had a problem with the belt that came with the unit, but you might try the added brace on the opposite end of the motor and see if your belt last longer then. Hope this helps...........Catch

Hi, Catch -

Nice idea. Do you have a pic of your brace?

I've not had any motor vibration issues with my Thumlers, but I've heard others having a problem. My motor seems to run smoothly and cooly.

Bayou52

[Buck Neck It]

The motor on mine runs hot. This is a unit that was gifted to me after sitting around unused for many years. Oiling the bearings hasn't cured the problem. Anyone have a cure/or similar problem?

[carbine]

Mine runs hot as well. Nature of the beast? Regarding the OP original question, my Model B went 10 years, 4 hrs a week before I replaced the belt. Got stretched

[Bayou52]

The motor on mine runs hot. This is a unit that was gifted to me after sitting around unused for many years. Oiling the bearings hasn't cured the problem. Anyone have a cure/or similar problem?

I read where these Thumler's motors were overload protected so they are supposed to shut off when overloaded or over heated. Has your moter gotten so hot as to actually shut off?

Bayou52

[Buck Neck It]

I haven't used it very much yet. I am one of those sluts who doesn't mind shooting tarnished brass, but I could reform my ways! I ran it once with a heavy load for 4 hours and it didn't kick out or burn up. It runs hot even with the belt off.

The belt definitely looks like an off-the-shelf o ring.

[Bayou52]

I haven't used it very much yet. I am one of those sluts who doesn't mind shooting tarnished brass, but I could reform my ways! I ran it once with a heavy load for 4 hours and it didn't kick out or burn up. It runs hot even with the belt off.

The belt definitely looks like an off-the-shelf o ring.

I typically run my Thumlers in 4 hour sessions. I've run it as much as 8 hours in one session. I run it with a full 15 pound load each time. This motor feels warm, but never hot. It has never shut itself off.

Other than the factory belts not lasting worth a flip, the Thumlers has worked well for me. O-rings have cured that situation. My tumbler is now 2 years old.....

Bayou52