7 replies to this topic

[iron Mike]

Hello everyone. Been awhile and my ss16 twin with 42"snow thrower is working great after a rebuild. My problem is I can't find a shear pin for the thrower. I ate an engine block the other morning and bent my auger up really bad,snapped the drive chain at the master link and I don't think that is supposed to happen. Can anyone tell me about shear pins for this thrower and where to put them. I keep hearing"just put a roll pin in there" or "just use a grade 2 bolt" but I would like to do this right. Any help would be greatly appreciated. Thanks guys,Mike.

[superaben]

A shear pin is essentially a cheap bolt.  A standard grade two works well for something this small.  If you were going to engineer it right, the bolt"s shear strength is what you go by and then you figure out what the capacity of the implement is. 

 

You could figure it out like an old farmer explained to me.  He was a wag.  He said to me one time, "You know how they figure out the bridge weight limit signs?  They drive bigger and bigger trucks over a new bridge until it collapses.  Then they rebuild it and put a a sign up with the weight that broke it."

 

Ben W.

[MH81]

There are a lot of shear pins out there, the trick is going to be finding the right one.
Like Ben said, some of it will be a guess, for several reasons.
1) odds are the OEM piece is no longer available.
2) most of the ones that are out there would be for two stage augers and may not be designed for the right shear strength for a single where the auger is doing all the work.
3) These machines have been worked. Many of them without any love for decades. Many of the shear pins have been converted to bolts in an attempt to remove some of the slop, in other words, diameter may be an issue.

At the farm, I've even seen home made pins in some equipment we've picked up. A bolt with a cuts in it at the right spots about half way thru. It would have been better if they had gone clear around so the shear strength is roughly the same however the bolt is in there.

Any idea what diameter the hole is now? If 1/4", there seem to be several options out there.

This one is from an Ariens. You not only need to get the diameter and length right, but also the shear points need to line up with the shaft / auger line.

Sorry to hear you damaged your blower. Gad you are going to be able to put it back together

[MH81]

Out of curiosity, I looked at a couple of single stage blower parts explosions at sears. The models I looked at dont show a shear pin that I could see, not even an NLA one.
What model number do you have.

[boyscout862]

A shear pin is essentially a cheap bolt.  A standard grade two works well for something this small.  If you were going to engineer it right, the bolt"s shear strength is what you go by and then you figure out what the capacity of the implement is. 

 

You could figure it out like an old farmer explained to me.  He was a wag.  He said to me one time, "You know how they figure out the bridge weight limit signs?  They drive bigger and bigger trucks over a new bridge until it collapses.  Then they rebuild it and put a a sign up with the weight that broke it."

 

Ben W.

Ben, when I was a town engineer, I would stand on a bridge when a big dump truck drove over. My calibrated feet would tell me what the posting should be. On atleast one occasssion a state engineer did the formal calculations and came up with the same number. I had many arguments with the state engineer in charge of bridges. Finally I got him to come out and look at what I was talking about. At the first bridge we looked at, he realized that I was right and his inspectors had not been getting under the bridges. They left me alone after that.

 

Look for shear pins for walk behind blowers. They may work for you. Good Luck, Rick

[iron Mike]

Out of curiosity, I looked at a couple of single stage blower parts explosions at sears. The models I looked at dont show a shear pin that I could see, not even an NLA one.
What model number do you have.

I will check the model number but now that I think about it I saw that blow up also and didn't see any shear pins,just bolts.

[iron Mike]

A shear pin is essentially a cheap bolt.  A standard grade two works well for something this small.  If you were going to engineer it right, the bolt"s shear strength is what you go by and then you figure out what the capacity of the implement is. 

 

You could figure it out like an old farmer explained to me.  He was a wag.  He said to me one time, "You know how they figure out the bridge weight limit signs?  They drive bigger and bigger trucks over a new bridge until it collapses.  Then they rebuild it and put a a sign up with the weight that broke it."

 

Ben W.

I'll try grade two bolts. Thanks.

[iron Mike]

I'll try grade two bolts. Thanks.

Near as I can tell that shaft is keyed so I guess there is no give there. Just got to be careful.