I'm in shear pin purgatory! Please help

[IslandTractor]

[FONT=Arial, Helvetica, sans-serif]Your point doesn become valid however - for the owner who wants to upgrade his smoothbore shear bolt protection to slip clutch but DOESN'T believe in preventative maintenance

//greg//
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Or for the owner who thinks it wise to rely on two levels of protection when possible as with retrofitted slip clutches on smoothbore shafts. Kinda like wearing seat belts in a car with air bags.

 

[greg_g]

I missed that typographical error. It should read "Your point does become valid....." Sorry

//greg//

 

[Rara Avis]

Kinda like wearing seat belts in a car with air bags.

Not really, because no auto manufacturer will certify that you are safe in a car with airbags, unless you are wearing your seatbelt...

 

[IslandTractor]

Not really, because no auto manufacturer will certify that you are safe in a car with airbags, unless you are wearing your seatbelt...

I just knew that some jailhouse lawyer would come along to pick apart my analogy.

Point remains, that the combo of slip clutch plus shear pin may be somewhat excessive it is not silly. While it should be unnecessary with a properly functioning and well maintained slip clutch it is not silly and doesn't interfer at all with the slip clutch. It is only really an issue for those who are adapting a slip clutch to a mower or implement with a smooth shaft and as the slip clutch must be attached to that shaft with a bolt anyway what is the harm of using a grade 2 bolt to so so?

 

[Rara Avis]

I just knew that some jailhouse lawyer would come along to pick apart my analogy.

Point remains, that the combo of slip clutch plus shear pin may be somewhat excessive it is not silly. While it should be unnecessary with a properly functioning and well maintained slip clutch it is not silly and doesn't interfer at all with the slip clutch. It is only really an issue for those who are adapting a slip clutch to a mower or implement with a smooth shaft and as the slip clutch must be attached to that shaft with a bolt anyway what is the harm of using a grade 2 bolt to so so?

YOU MUST be a belt AND suspenders kind of guy...

 

[greg_g]

... what is the harm of using a grade 2 bolt to so so?

For torque-adjustable slip clutches like mine, the harm is financial. I can adjust the spring tension on mine to be compatible with the PTO horsepower rating of the tractor to which it's connected. But what's the sense of doing that, if a fella keeps sticking in $3.50 shear bolts before the clutch even has a CHANCE to slip?

There is none - because there's no reasonable substitute for good maintenance. And testimony here clearly demonstrates real world experience on how minor that maintenance actually is. So the prudent thing to do is fasten with a grade of bolt that you KNOW will still be holding - when the slip clutch is actually given a chance to do its job.

//greg//

 

[fattyfat1]

breaking shear bolts is a great way for my cutter to tell me it's time to service it's slip clutch! ifn it aint broke-don't fix it! with two jobs and two little boys, this is the best way for me to know that the clutch needs adjusting. don't have time nor patience to putz around with that thing once a month, for a "maybe". sometimes i can go all year only adjusting in spring, sometimes not, but replacing a 99 cent bolt twice a year is way easier than wrestling that stupid plastic shroud and puttering with that clutch. run em both! just my 2cents..

 

[gemini5362]

For torque-adjustable slip clutches like mine, the harm is financial. I can adjust the spring tension on mine to be compatible with the PTO horsepower rating of the tractor to which it's connected. But what's the sense of doing that, if a fella keeps sticking in $3.50 shear bolts before the clutch even has a CHANCE to slip?

There is none - because there's no reasonable substitute for good maintenance. And testimony here clearly demonstrates real world experience on how minor that maintenance actually is. So the prudent thing to do is fasten with a grade of bolt that you KNOW will still be holding - when the slip clutch is actually given a chance to do its job.

//greg//

Why the big problem with people that like to do both. I think you have made your point you seem to think it is a bad idea. but other people prefer to use both methods. I personally agree I would rather just put in a cheap bolt and go my merry way rather than mess with the slip clutch all the time. Do your preventative maintenance all the time and keep your equipment in tip top condition and we will all aplaud you for it. Your financial reward will come if you decide to sell that equipment and it is in good shape and you will get a reward in knowing that whatever you want to do with your equipment you know it will be ready to work. But for the people that for whatever reason does not meet your standards of excellence please dont knock them for doing what maintenance they have the time or knowledge to do.

 

[N80]

There really is no viable argument against someone using a shear bolt and a slip clutch if they want to unless they are actually paying THREE DOLLARS AND FIFTY CENTS per bolt. I was unaware that anyone charged that much for a bolt designed to fail. I think I pay somewhere around 5 cents each.

 

[gemini5362]

There really is no viable argument against someone using a shear bolt and a slip clutch if they want to unless they are actually paying THREE DOLLARS AND FIFTY CENTS per bolt. I was unaware that anyone charged that much for a bolt designed to fail. I think I pay somewhere around 5 cents each.

I think in an earlier post he mentioned that he was using the actual OEM shear bolts. I am sure that they are tested for actual break strength and certified to break at that point. Personally I agree with you I just put a 1/4 inch bolt or depending on what it is I use a 3/8 bolt that I get at TSC by the pound.

On my driveshafts with spines on it I use a shear bolt to hold them in place I have had those bolts shear before. The slip clutch would not offer any protection against that type of movement.