I always loosen b&c after operation.....Right?

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nicklt040

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I always loosen the b&c on my saws after operating. I read this in a owners manual. The manual said if you leave the b&c tight it coul mess the bearings or seals up. I have some pretty old saws, I never bought on new though. So I dont know how the owners before me operated/cared for their saws. I have not had a crank bearing or seal go out on any of my saws. I take it that the manual is right it makes sense to me. I just read a thread that stated someone had a 6 month old saw that torched the piston because of a crank seal air leak. This was in the huskey vs. stihl post. Maybe it was the operator not the manufactuer, maybe?
 
Its a good idea. Usually after running a tank of gas through the saw the chain will have stretched a little and be loose enough that you dont have to loosen it any more. But if the chain is tight and the bar is warm, then go ahead and loosen it.
 
If your chain is adjusted properly and not too tight it should be fine. Temperature changes can stretch or shrink a chain so that is why it would say that in the manual.
 
I read the same thing...

...In the manual that came with an MS310. I was kind of befuddled myself because you're not supposed to tension a chain when it is hot, right? So if you tension it properly(when b&C has cooled)it's not going to contract much more while sitting in your garage.
 
seems this would only apply if you are dumb enough to adjust your chain hot. if your chain stretches out that far to need it, something is wrong. like oiler is plugged up or you started with a loose chain.

if you've done maintenance and adjusted your chain to proper tension before you start your engine. when saw cools back down to ambient temps. max saw can contract is back to starting point.

I always loosen the b&c on my saws after operating. I read this in a owners manual. The manual said if you leave the b&c tight it coul mess the bearings or seals up. I have some pretty old saws, I never bought on new though. So I dont know how the owners before me operated/cared for their saws. I have not had a crank bearing or seal go out on any of my saws. I take it that the manual is right it makes sense to me. I just read a thread that stated someone had a 6 month old saw that torched the piston because of a crank seal air leak. This was in the huskey vs. stihl post. Maybe it was the operator not the manufactuer, maybe?
 
I always loosen the b&c on my saws after operating. I read this in a owners manual. The manual said if you leave the b&c tight it coul mess the bearings or seals up. I have some pretty old saws, I never bought on new though. So I dont know how the owners before me operated/cared for their saws. I have not had a crank bearing or seal go out on any of my saws. I take it that the manual is right it makes sense to me. I just read a thread that stated someone had a 6 month old saw that torched the piston because of a crank seal air leak. This was in the huskey vs. stihl post. Maybe it was the operator not the manufactuer, maybe?

I figure it is in the cant hurt, and might help catagory. If I have to tighten my chain while cutting, then I loosen it when I am done till every thing cools down.
 
Odd

That's super strange and I'd like to see some feedback from the Tech's on this... I've NEVER loosened a chain when done for the day or week or however long. I've never had a bearing go bad either. As far as the chain stretching, Stihl chain and the Oregon LGX I have NEVER had stretch a bit no matter the heat conditions... Some of the other Oregon and Carlton I noticed would loosen up a couple times before being consistent, but never the 2 aforementioned... If a chain really stretches, wouldn't that be dangerous? How exactly and what exactly stretches on a chain. I doubt the links can, I don't think the pins that hold the links together can.?.? Which means by my guessing maybe the drive links and how they sit on the clutch??? Explain exactly what stretches eh?

:popcorn: :confused:
 
seems this would only apply if you are dumb enough to adjust your chain hot. if your chain stretches out that far to need it, something is wrong. like oiler is plugged up or you started with a loose chain.

if you've done maintenance and adjusted your chain to proper tension before you start your engine. when saw cools back down to ambient temps. max saw can contract is back to starting point.

+1
I AGREE.
 
That's super strange and I'd like to see some feedback from the Tech's on this... I've NEVER loosened a chain when done for the day or week or however long. I've never had a bearing go bad either. As far as the chain stretching, Stihl chain and the Oregon LGX I have NEVER had stretch a bit no matter the heat conditions... Some of the other Oregon and Carlton I noticed would loosen up a couple times before being consistent, but never the 2 aforementioned... If a chain really stretches, wouldn't that be dangerous? How exactly and what exactly stretches on a chain. I doubt the links can, I don't think the pins that hold the links together can.?.? Which means by my guessing maybe the drive links and how they sit on the clutch??? Explain exactly what stretches eh?

:popcorn: :confused:


I am like you never had any problems, As for what stretches, all parts of the chain, Do to changes in temp. steel expands and contracts
 
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Temp

+1, and for each metal it expands at different rates

The only thing is, we're only talking a couple hundred degrees here. I don't think metal, especially hardend high carbon steel expands/contracts that much for just a couple hundred degrees... I mean, we're talking like 1" of expansion for say 60 teeth, that's a lot of difference wouldn't you agree??? Ya'll get where I'm coming from??? It just seems strange is all...

:confused:
 
The only thing is, we're only talking a couple hundred degrees here. I don't think metal, especially hardend high carbon steel expands/contracts that much for just a couple hundred degrees... I mean, we're talking like 1" of expansion for say 60 teeth, that's a lot of difference wouldn't you agree??? Ya'll get where I'm coming from??? It just seems strange is all...

:confused:

Actually, not anywhere near 1". Look how far a chain adjuster adjusts. An 1/8" movement is the difference between extremely tight and really loose. Furthermore, consider that chain length is more than twice bar length. A 20" bar is going to be 50" or more of chain length. Even if you were talking an 1", that's still only 2% on a 20" chain.
 
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hmmmmm

Actually, not anywhere near 1". Look how far a chain adjuster adjusts. An 1/8" movement is the difference between extremely tight and really loose. Furthermore, consider that chain length is more than twice bar length. A 20" bar is going to be 50" or more of chain length. Even if you were talking an 1", that's still only 2% on a 20" chain.

I reckon... Still seems like alot though eh? 2% is quite a bit even for metal. Think of it this way, say you have a sheet of steel that is cut to 20'X40'. That means when heated this sheet is now 20'5" X40'10". In all actuality, thats' no where near possible I don't believe. I dunno, it still just doesn't make any sense to me for it to expand/contract that much on such a small length. Try this. When someone buys a new chain, overtighten it just a bit, like me, I think you'll find that it doesn't actually stretch. It stays just as tight all the time. I overtighten all my chains since I started running newer saws due to the rpms and throwing chains. I also notice they don't loosen up ever... I'd like to see some math with tensile and yields for the types of metals they are using with some heat variables to see if this is really possible. Aren't the pins made of carbide??? This is actually a super interesting thread...

:confused:
 
I reckon... Still seems like alot though eh? 2% is quite a bit even for metal. Think of it this way, say you have a sheet of steel that is cut to 20'X40'. That means when heated this sheet is now 20'5" X40'10". In all actuality, thats' no where near possible I don't believe. I dunno, it still just doesn't make any sense to me for it to expand/contract that much on such a small length. Try this. When someone buys a new chain, overtighten it just a bit, like me, I think you'll find that it doesn't actually stretch. It stays just as tight all the time. I overtighten all my chains since I started running newer saws due to the rpms and throwing chains. I also notice they don't loosen up ever... I'd like to see some math with tensile and yields for the types of metals they are using with some heat variables to see if this is really possible. Aren't the pins made of carbide??? This is actually a super interesting thread...

:confused:
We would need to know what the thermal expansion rate is.
 
2% LOLOLOL

Steel runs about 10.8 to 13 x 10E-6 ppm per degree K (call it C..). This the LINEAR expansion coefficient, not "volumetric".

You do the math... Chain steel would be closer to the low end.

Oh... the bar get hotter too ;)
 
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2% LOLOLOL

Steel runs about 10.8 to 13 x 10E-6 ppm per degree K (call it C..). This the LINEAR expansion coefficient, not "volumetric".

Yeah, I didn't know what the figure was. I thought the expansion rate was more than that. What do you think; are bent cranks and ruined seals an old wives' tale?
 
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