ArboristSite.com Sponsors
 
 


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

Discussion in 'Chainsaw' started by nicklt040, Mar 12, 2008.

  1. nicklt040

    nicklt040 ArboristSite Operative

    Joined:
    Feb 23, 2008
    Messages:
    104
    Likes Received:
    7
    Location:
    georgia
    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?
     
  2. HUSKYMAN

    HUSKYMAN Addicted to ArboristSite

    Joined:
    Mar 23, 2001
    Messages:
    3,350
    Likes Received:
    225
    Location:
    Birch Run, Michigan
    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.
     
  3. huskydave

    huskydave Addicted to ArboristSite

    Joined:
    Mar 7, 2007
    Messages:
    1,452
    Likes Received:
    219
    Location:
    Ontario Canada
    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.
     
  4. outdoortype

    outdoortype AboristSite Guru

    Joined:
    Sep 23, 2006
    Messages:
    794
    Likes Received:
    77
    Location:
    Virginia
    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.
     
  5. Del_

    Del_ Tree Freak

    Joined:
    Feb 18, 2002
    Messages:
    20,590
    Likes Received:
    2,272
    Location:
    Where the universes are.
    I pay special attention to long bar/chains when it's around freezing or below. At normal temperatures I never worry about it.
     
    Ole Farmerbuck likes this.
  6. 046

    046 Addicted to ArboristSite

    Joined:
    Apr 8, 2004
    Messages:
    4,454
    Likes Received:
    277
    Location:
    Oklahoma
    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.

     
  7. Saw Bones

    Saw Bones ArboristSite Operative

    Joined:
    Oct 6, 2007
    Messages:
    392
    Likes Received:
    42
    Location:
    Lafayette, La
    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.
     
  8. ciscoguy01

    ciscoguy01 Addicted to ArboristSite

    Joined:
    Oct 26, 2006
    Messages:
    2,079
    Likes Received:
    345
    Location:
    'daks
    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:
     
  9. reachtreeservi

    reachtreeservi Banned

    Joined:
    Feb 23, 2006
    Messages:
    1,096
    Likes Received:
    240
    Location:
    Georgia
    +1
    I AGREE.
     
    04ultra and Just Mow like this.
  10. Ray Bennett

    Ray Bennett AboristSite Guru

    Joined:
    Jan 31, 2006
    Messages:
    617
    Likes Received:
    127
    Location:
    western maryland
    I have never needed to touch mine.
     
    Just Mow likes this.
  11. czar800

    czar800 ArboristSite Operative

    Joined:
    Nov 27, 2007
    Messages:
    490
    Likes Received:
    84
    Location:
    Western Pa

    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
     
    Last edited: Mar 12, 2008
  12. spacemule

    spacemule The Peanut Gallery

    Joined:
    Apr 3, 2003
    Messages:
    18,575
    Likes Received:
    2,088
    Location:
    the sideways 40
    All metals expand and contract with temperature changes.
     
  13. gink595

    gink595 Banned

    Joined:
    Feb 4, 2008
    Messages:
    5,327
    Likes Received:
    804
    Location:
    Hooterville
    +1, and for each metal it expands at different rates
     
    Last edited: Mar 12, 2008
  14. ciscoguy01

    ciscoguy01 Addicted to ArboristSite

    Joined:
    Oct 26, 2006
    Messages:
    2,079
    Likes Received:
    345
    Location:
    'daks
    Temp

    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:
     
  15. spacemule

    spacemule The Peanut Gallery

    Joined:
    Apr 3, 2003
    Messages:
    18,575
    Likes Received:
    2,088
    Location:
    the sideways 40
    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.
     
    Last edited: Mar 12, 2008
  16. Andyshine77

    Andyshine77 Addicted to ArboristSite

    Joined:
    Jan 25, 2004
    Messages:
    7,178
    Likes Received:
    1,419
    Location:
    Cincinnati, OH
    I always loosen my chains at the end of the day, it's an old habit of mine, it only takes a few seconds, so why not do it just to be safe.
     
    SawTroll likes this.
  17. ciscoguy01

    ciscoguy01 Addicted to ArboristSite

    Joined:
    Oct 26, 2006
    Messages:
    2,079
    Likes Received:
    345
    Location:
    'daks
    hmmmmm

    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:
     
  18. spacemule

    spacemule The Peanut Gallery

    Joined:
    Apr 3, 2003
    Messages:
    18,575
    Likes Received:
    2,088
    Location:
    the sideways 40
    We would need to know what the thermal expansion rate is.
     
  19. Lakeside53

    Lakeside53 Stihl Wrenching

    Joined:
    Dec 25, 2004
    Messages:
    24,817
    Likes Received:
    1,643
    Location:
    Woodinville, WA
    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 ;)
     
    Last edited: Mar 12, 2008
  20. spacemule

    spacemule The Peanut Gallery

    Joined:
    Apr 3, 2003
    Messages:
    18,575
    Likes Received:
    2,088
    Location:
    the sideways 40
    I'm too pooped to do the math. :cheers:
     

Share This Page