snapped chain.....twice

[Dr_Zinj]

I may have missed where you said what the shear bolt was.

A lot of times I'll see people using any old bolt or rod in place of the shear pin/bolt.

Such is a disaster waiting to happen.

Regular bolts are hardened metal. Shear pins are soft metal specifically to be cut through. I've made "shear pins/bolts" from scratch by cutting rod stock or from regular bolts and heating them red hot and letting them cool slowly without quenching in order to take the temper out of them, rendering them much softer than normal. Still not the best solution, but can work in a pinch.

 

[SARG]

I may have missed where you said what the shear bolt was.

A lot of times I'll see people using any old bolt or rod in place of the shear pin/bolt.

Such is a disaster waiting to happen.

Regular bolts are hardened metal. Shear pins are soft metal specifically to be cut through. I've made "shear pins/bolts" from scratch by cutting rod stock or from regular bolts and heating them red hot and letting them cool slowly without quenching in order to take the temper out of them, rendering them much softer than normal. Still not the best solution, but can work in a pinch.

Except that many manufacturers such as Martin Meteor use standard grade bolts as "shear" bolts direct from the factory.

 

[Jay4200]

It is my present feeling that the Ecnor blower is better built and wish I had bought one of them this time too.

My 6' Econor does seem to be built well, although (oddly) Econor blowers are relatively light in all size classes. Also, the well-respected Puma is the same blower rebranded.

JayC

 

[slowzuki]

Woah right there! Once you have blown the chain once, it will not hold the same again! All the links on the tension side of the original blow will always be weak in the future.

I chased the first chain I had on my blower with master links before I learned and bought a 10 ft roll. The new chain drasitically reduced my problems from a break every 5 hours to about a break a season. (I put about 100 hours a winter on blowing)

I also reduced my shear bolt size and grade but it still breaks chains before bolts.

Okay I am about to give up. Snapped the chain twice again. Once yesterday and again today. I have the 60H on already and the bolts just won't shear for some reason. It has the right bolts. I now have 5 master links in the chain. I did get a new chain so might change it out. Just don't understand this problem.

 

[slowzuki]

Shear bolts aren't always made from soft material. The neighbours MF baler uses Grade 8 bolts as shear bolts. It warns not to use soft bolts. I did once as a last resort, what a pain to get the smeared bolt out.

Shear protection is just designing a component to fail at a specific torque to save some other component.

I may have missed where you said what the shear bolt was.

A lot of times I'll see people using any old bolt or rod in place of the shear pin/bolt.

Such is a disaster waiting to happen.

Regular bolts are hardened metal. Shear pins are soft metal specifically to be cut through. I've made "shear pins/bolts" from scratch by cutting rod stock or from regular bolts and heating them red hot and letting them cool slowly without quenching in order to take the temper out of them, rendering them much softer than normal. Still not the best solution, but can work in a pinch.

 

[Ford tractor]

Pulling the pins and checking for free movement should be part of everyone's annual PM.

It is sad that the owner manuals are so lacking in detail about the the shear pins and slip clutches.:confused2:

They seem to assume that everyone knows this stuff.
.

Actually, my equipment manuals all give explicit instructions on care and feeding of slip clutches or shear bolts. I did have to actually break down and open them up:laughing:. Maybe the less expensive stuff with 'Engrish' manuals don't have that section?

 

[kevinj]

Actually, my equipment manuals all give explicit instructions on care and feeding of slip clutches or shear bolts. I did have to actually break down and open them up:laughing:. Maybe the less expensive stuff with 'Engrish' manuals don't have that section?

Kubota's english translations are sometimes less than acceptable.

They say something to the effect of making sure the shear bolts are properly tightened.

 

[Don87]

Woah right there! Once you have blown the chain once, it will not hold the same again! All the links on the tension side of the original blow will always be weak in the future.I chased the first chain I had on my blower with master links before I learned and bought a 10 ft roll. The new chain drasitically reduced my problems from a break every 5 hours to about a break a season. (I put about 100 hours a winter on blowing)

I also reduced my shear bolt size and grade but it still breaks chains before bolts.

Exactly, and once a rock goes thru the sprcket, even though the chain didn't break at that exact time.........the chain is substantially weakened.

Best advice is to keep rocks out of the blower, especially one with an exposed chain.

 

[PILOON]

Looking at your pics and noteing the hours of usage suggest that you blow lots of rocks.
(your blower housing is really battle scared for those low hours)
Every rock hit weakens the shear bolt a tad more each time and every bolt sheared puts a good shock load on the chain.
As stated in another post, once the chain snapped it snapped the weakest link but then all the other links became that much weaker.

I don't think the blower is much at fault but rather your drive is.
I'd suggest a new chain and adjust the skid shoes higher to avoid plucking stones.

I know that blower and it is real tough but there is just so much it can take.

 

[flyingcow]

I'm going to drop this thread, but IMO every snowblower is designed to have a few rocks go thru it. What this guy has, is not a rock/shear bolt/or chain problem. I don't know what it is......brand new blower...climb up(the azz)of the company that built the blower.