How is this possible?

Discussion in 'Magna-Matic' started by Sprinkler Buddy, Aug 10, 2013.

  1. Sprinkler Buddy

    Sprinkler Buddy LawnSite Bronze Member
    from Florida
    Messages: 1,185

    I sharpen and balance my blades with Magna Matic products, love them by the way.

    Occasionally after sharpening a blade, one side will be way off balance. No apparent nicks prior to sharpening. You would think the blade would ware about the same at both ends. I'm not talking by just a little, that's the norm, I mean way off!

    You guys see this much when balancing your blades?
  2. windflower

    windflower LawnSite Bronze Member
    Messages: 1,098

    Any grass build up on the blade? (That green slime on the back of the blade) Did it center on the balancer? Only time I've ever seen it is when the lifters are getting pretty worn.
  3. Sprinkler Buddy

    Sprinkler Buddy LawnSite Bronze Member
    from Florida
    Messages: 1,185

    No grass build up and I use low lift blades, very little if any wear.
  4. Magna-Matic

    Magna-Matic Sponsor
    Messages: 839

    Hello All,

    Please remember that mass of the blade may not be evenly distributed across the blade.

    Another possibility of a blade being very out of balance often, is if the center hole is not stamped in center of the blade. Hold the blade vertically, and measure the distances from left to right of the center hole. If it is off more than 0.015 inches the blade was faulty from the start. This condition is very difficult to correct, and the blade should not be used.
  5. CQ_DX

    CQ_DX LawnSite Member
    from MA
    Messages: 67

    What model equipment and what brand blades are we talking about here?
    What model M-M balancer are you using?

    Presumptions (correct me if wrong):

    1. Your blades have been cleaned WELL prior to sharpening - true?
    2. You are NOT using adapter inserts inside the center mounting hole - true?
    3. You are checking your M-M balancer and keeping it free of metallic build up clinging to the magnets - true?
    4. The blades you are sharpening do not have anything attached, like brackets, trash cups, etc. - true?
    5. There are no stickers/labels attached - true?
    6. Paint is not flaking off - true?
    7. You have removed the blade from the balancer and changed it 180 degrees and the same end remains the heavy end and dips just as far and just as fast - true?
    8. Same as above but now you turn the blade over and have the opposite surface against the cone/magnets and see no difference - true? And then turn it 180 degrees and no difference - true?
    9. This is a single blade and NOT a stacked blade assembly - true?
    10. You have checked flatness - true? What are the differences in the gaps and how long are the blades?

    If the above are all true, there is no explanation why a blade is out of balance after sharpening and checking for balance with any of the M-M balancers other than your technique. Unbalance cannot happen as you are in complete control to bring it into balance - or not.

    I don't care if the hole is off center - you can counter act this by processing and checking the balance. If you have an 8 foot 2x4 and the hole is two inches off center, you can cut 2 inches off the long end and now the mass is fairly equal about the center point - and you can fine tune the balance from there. Granted the tip to tip distance is now shorter but this is not the concern nor the issue.

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