Caroni Flail Belt Failure

[Eagleview]

Does your flail have a spring loaded tensioning pully?

No mine is tensioned by lifting the top pulley and shaft with a bolt and then locking off . With the usual 3/8" slack that most belts run they can still slip when need be to avoid shock loads to the gearbox and up the shaft to the tractor . Mine runs 5 B section "matched" cog belts , ive had chunks of wood jam the rotor and have smoked the belts before i can get the PTO shut off . For those of you that have the same setup as mine you must raise the gearbox as well as the pulley to keep the shaft parallel . If not the top pulley will not be inline with the bottom pulley and the outside belts will be loose . You will find with that little spring at certain revs (critical mass) the belts will get a "wave" happening and the idler will move in and out . This i think is what is generating all the heat as the belts are slipping when the idler is deflected . A stronger spring may help but if you can push your foot on the drive side of the belts and make the idler deflect it is not strong enough . A thing with tensioning springs with a threaded rod is that the pull of the spring is fairly uniform as it is stretched (over that short distance) and i can't really see how it is expected to work . As you all would know , when you put your foot on the accelerator pedal on a vehicle with a return spring the effort does not get greater the further the pedal is pushed . Only tuned springs can do that and the one on that flail is not a tuned spring .

 

[sunspot]

I sent an email to Caroni asking for the belt dimentions.

 

[IslandTractor]

I sent an email to Caroni asking for the belt dimentions.

I googled the numbers I found on the belts on my TM1900. There is a B43 17x1090 belt (solid, classic section V belt) listed by a few international vendors (Germany, UK, UAE). I think the B stands for the solid classic section. The 43 seems to be inside length in inches which is the same as 1090mm. The 17mm is cross section width at top (widest part of V) (=about 2/3 inch). Height in cross section is 11mm.

I don't know what the NAPA or US standard size description is for these but there must be one. The belts seem to cost about 8-14 bucks each.

 

[SPYDERLK]

I googled the numbers I found on the belts on my TM1900. There is a B43 17x1090 belt (solid, classic section V belt) listed by a few international vendors (Germany, UK, UAE). I think the B stands for the solid classic section. The 43 seems to be inside length in inches which is the same as 1090mm. The 17mm is cross section width at top (widest part of V) (=about 2/3 inch). Height in cross section is 11mm.

I don't know what the NAPA or US standard size description is for these but there must be one. The belts seem to cost about 8-14 bucks each.

So its a B43 belt. You can get them quickly with a phone order to McMaster Carr -"Gates" Brand belts. That is a B section belt with a pitch length of 43 inches. This corrresponds to an outside length of 46" which is much easier to measure.
larry

 

[IslandTractor]

I also found the Gates B43 at RocklandAuto dot com for a $7.35 each (about $3 less than McMaster-Carr). They are described as "GATES Part # B43 {Hi-Power II Belt B 21/32" x 46"} Category: Classical Section Wrapped V-Belt" which sounds right.

Now, I need to find a bigger spring or a solid threaded link. A new threaded link would be nice but then I'd need to deal with an attachment point. Maybe using a small section of chain to replace the existing spring would be easiest. Is there any reason not to just reinforce the existing spring by wrapping wire tightly through it?

 

[Reg]

Right, Gates.com

One OTHER thing that can lead to heating is pulley circumference; too small requires too much bending, absorbs too much power and requires too much more tension.

Ummm, I think Iron Horse meant resonanance, but I'm just guessing.

I'll be talking to Agri-Supply today about the slack spot on mine.

BTW, Gates predict 20,000 to 25,000 hours life for properly selected and maintained V belts. Looking at the hour meter and odo on my truck, that could be equivalent to somewhere around a million truck miles.

 

[sunspot]

You guys are GOOD. I tried a goggle and came up empty
NAPA should be able to cross reference a Gates belt.

 

[SPYDERLK]

I also found the Gates B43 at RocklandAuto dot com for a $7.35 each (about $3 less than McMaster-Carr).

Now, I need to find a bigger spring or a solid threaded link. A new threaded link would be nice but then I'd need to deal with an attachment point. Maybe using a small section of chain to replace the existing spring would be easiest. Is there any reason not to just reinforce the existing spring by wrapping wire tightly through it?

Good price. Glad you found it. Be careful trying to get more out of the existing spring in any way other than stretching it a little further. Any other means of increasing the preload should go around or thru the center of the spring without hooking too the spring anywhere. The spring is fine within itself, but grafting onto it will accelerate failure.
larry

 

[IslandTractor]

Be careful trying to get more out of the existing spring in any way other than stretching it a little further. Any other means of increasing the preload should go around or thru the center of the spring without hooking too the spring anywhere. The spring is fine within itself, but grafting onto it will accelerate failure.
larry

I'm a little confused. I am unsure of the terminology for starters. What I had in mind was some way to avoid needing to figure out how to attach a new solid threaded tensioner. There is a slightly larger than 1/8 inch hole manufactured into the short stock Caroni tensioner where the spring attachs and I don't know if I can find A) similar threaded rod, B) rod with an attachment point at one end. Maybe those are common items. My thought was that I would continue to use the spring as a connector but simply "bypass" the spring by wrapping more wire tightly through it with multiple wraps top to bottom so that in effect it was no longer a spring but just a "solid" connector from the threaded tensioner to the tensioner arm. Jury rigged to be sure. I just don't know even what terminology to use in trying to locate a threaded rod or chain that would allow me to replace the spring but still connect to the tensioner arm.

Edit: I also just realized that if the spring is 1/8 inch wire that if I want a solid connector I could just use a single strand of 1/8 inch wire from tensioner idle arm directly to the existing threaded tensioner. If a 1/8 inch spring is strong enough then is it reasonable to assume that you could replace it with straight 1/8 inch wire?

 

[SPYDERLK]

I checked and measured the tensioning spring. It is a simple 1/8 inch (0.15 inches by micrometer) by 3 inches extension spring with standard machine hooks. I forgot to measure the diameter but it is about an inch. It should not be too hard to find a heavier duty replacement but I haven't tried yet.

I also tightened mine up by another inch and a half. I'll do some mowing and see what the effect is on belt guard temperature.


(Note: 1 hour of medium/heavy mowing left the belt cover too hot to touch for more than a couple of seconds even after taking up most of the adjustment on the spring.....Will look for a heavier spring first and also, per IronHorse's suggestion, a chain to replace the spring.)

The picture associated with the quoted post shows your belts in good shape but very little spring preload. I assume you pulled it out another inch or so after the pic. And it still gets hot. -- Try relaxing the spring. Does it go back to its original length? Im thinking the spring may have taken a new set and you arent really getting anymore out of it. It seems putting on the belts may require the idler to pivot all the way back and your extra preload stretch added to that could have "sprained" the spring.

Also you gotta take a look at what the idler does under load. The belts pull down into the grooves some and the idler must be free to pivot in to keep the slack side of the belts snug.
larry