Magic shrinking belts

[dontknowanything]

This is a new one for me.

We have a McConnell topper (it's sh!t, but that's another story). Last year I changed all 5 belts that driver the flail with a matched set of new ones. They fit on perfectly, and the tensioner worked etc. This morning, the tensioner spring snapped, which turns out to have been due to four of the 5 belts shrinking by about 15mm (they are 1780mm belts), and pulling the spring in half.

One of the belts is still the correct length, the other four I had to cut off with a saw, as they were too tight even without the tensioner in place. WTF? No one I know has ever seen belts shrink like this, what's going on?

 

[llamedos]

Is the fabric in the Kevlar?


In a previous life ....

 

[icanshootwell]

Get rid and get yourself a flail, lot less hastle

 

[dontknowanything]

Get rid and get yourself a flail, lot less hastle

It is a flail

 

[icanshootwell]

OK its the ones on the side i guess, you will have to put all new ones on and cross your fingers, you can still get rid

 

[Courier]

Take all 5 unused belts back to the supplier and get another set of a better make.

 

[Flat 10]

Random

 

[Zebbedee]

Yes I have come across belts shrinking on my lime spreader, no idea why and nobody believed me either

 

[Zebbedee]

I replaced with a top quality belt I think they were called red back ? Or similiar and they are excellent

 

[Robt]

Belts will shrink over time.... as they dry out or cool down then dry out they will shrink. Once they were warm, had you have gotten that far. You would have found they were orginal length. A couple of tenths of a mm will make all the difference. Also remember we are talking ag spec grade here not military or race spec rubber

 

[David.]

Aren't matched sets now a thing of the past, manufacturing process is much more uniformly accurate nowadays than in the old days when they had to rummage the entire stores to find some exactly alike.

 

[Hairy Bob]

Not necessarily, there's still a bit of variance between batches. Take 10 brand new belts, with the same part number and different batch numbers, measure them against each other and you might find 2-3 pairs among them. I'd be surprised if you find a set of 3 the same, I never can when I've got a set of 3 or 4 to replace!
Source: working on ag, construction, mining and factory machinery for the last 12 years.