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Thread: Cam Rotation: Over/under rotated

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    Default Cam Rotation: Over/under rotated

    My question to all of you is this: What difference on speed, accuracy, draw lenght, draw weight, let-off, etc. does either over or under rotation of the cams make?....AND....how do you correct cam rotation? Cam sync is not an issue. The cams are timed equally in this senario.
    -2011 Martin Silencer 63# 29.5", Limbsaver prism elite .029 sight, Alpine Whisperflite drop away rest, Alpine 5 arrow quiver, G5 1/4" Meta Peep, Carbon Express 8" stabilizer, Gold Tip Warrior and Expedition Hunter (385gr), G5 Montec
    -2011 Martin Silencer, 73# 29.5", Limbsaver prism elite .019 sight, QAD Ultra Rest Pro LD, Tight Spot 5 arrow quiver, 1/4" G5 Meta peep, Carbon Express 8" stabilizer, Gold Tip Expedition Hunter 7595 camo (441gr), G5 Montec BH.

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    Twist the cables/untwist the string will advance the cams.
    Untwist the cables/twist the string will under-rotate the cams.
    (think I got the advance/under-rotate right)

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    Quote Originally Posted by Spiker View Post
    Twist the cables/untwist the string will advance the cams.
    Untwist the cables/twist the string will under-rotate the cams.
    (think I got the advance/under-rotate right)
    I don''t know if I get it right or not either. I understand the terms over or under rotate better.

    mudpig, there's a good sticky thread on AT about optimizing the rotation of Cat cams for better performance. This could be used for almost any dual or binary cam system.

    I'm not sure about it myself. Essentially over rotating a cam will be increasing the draw length. It gives more speed, more letoff, and usually a harsher draw. This done by twisting up the cables and/or untwisting the string.

    The opposite is true for under rotating the cams. It's explained better on AT.
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    I think "over-rotated" and "under-rotated", are examples of horrible usage of the English language!

    They don't mean anything, because they mean opposite things to different people. And they use too many letters (and words) to say what needs to be said.

    When you draw a bow, you start at brace, and go to full draw. If you shorten the string, and/or lengthen the cables, you move the cams closer to their "full draw" position.

    You advance them.

    If you lengthen the string and/or shorten the cables, you back the cams up, away from their full draw position.

    You retard them.

    It's just like setting the ignition timing with an old distributer ignition system in a car. Same terminology, same results.

    Advancing the cams, reduces draw weight and draw length.

    Retarding the cams, increases the draw weight and draw length.

    Always, every time, every bow, every cam system.

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    I only use them terms because the word 'retarded' gets banned.

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    Quote Originally Posted by copterdoc View Post
    I think "over-rotated" and "under-rotated", are examples of horrible usage of the English language!

    They don't mean anything, because they mean opposite things to different people. And they use too many letters (and words) to say what needs to be said.

    When you draw a bow, you start at brace, and go to full draw. If you shorten the string, and/or lengthen the cables, you move the cams closer to their "full draw" position.

    You advance them.

    If you lengthen the string and/or shorten the cables, you back the cams up, away from their full draw position.

    You retard them.

    It's just like setting the ignition timing with an old distributer ignition system in a car. Same terminology, same results.

    Advancing the cams, reduces draw weight and draw length.

    Retarding the cams, increases the draw weight and draw length.

    Always, every time, every bow, every cam system.
    I cannot disagree Copperdoc, however most people don't understand mechanical terms when it comes to advancing and retarding of ignition timing and such but when you rotate something it is easier for the masses to understand...proper english aside.

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    Talking

    First: Thank you for all the answers. They help this newb understand things a little better.

    Second: With this new info.... is it advantagious (for maximized performance) to retard the cam timing, or is it best to be at TDC 0 Degrees??

    Third: Are there any downsides to retarding/advancing the cam timing??

    and...I think that I've found that Sticky at AT, so thanks for that. Haven't had a chance to read and reread it yet to full understanding.
    -2011 Martin Silencer 63# 29.5", Limbsaver prism elite .029 sight, Alpine Whisperflite drop away rest, Alpine 5 arrow quiver, G5 1/4" Meta Peep, Carbon Express 8" stabilizer, Gold Tip Warrior and Expedition Hunter (385gr), G5 Montec
    -2011 Martin Silencer, 73# 29.5", Limbsaver prism elite .019 sight, QAD Ultra Rest Pro LD, Tight Spot 5 arrow quiver, 1/4" G5 Meta peep, Carbon Express 8" stabilizer, Gold Tip Expedition Hunter 7595 camo (441gr), G5 Montec BH.

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    Quote Originally Posted by mudpig View Post
    First: Thank you for all the answers. They help this newb understand things a little better.

    Second: With this new info.... is it advantagious (for maximized performance) to retard the cam timing, or is it best to be at TDC 0 Degrees??

    Third: Are there any downsides to retarding/advancing the cam timing??

    and...I think that I've found that Sticky at AT, so thanks for that. Haven't had a chance to read and reread it yet to full understanding.
    In an ideal world you would want TDC 0 degrees. Some times you have to retard or advance them to get the propper draw length and such. It could also depend on the cam. From my experience on a bow that is a single cam I have found that if you cannot do TDC as you call it, it is better to have it advanced. The same goes for cams such as the NOS cams, CAT 1.5's or any cam with a lobe on it. Cams such as the CAT 2.0 or any cam that is lobeless I would say it would be of lesser importance. Also note I am basing my experrience on tunability and accuracy and not for maximum speed and such.
    Others may have had different experiences so I can only base this on my experiences along with others who have validated my findings.

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    Default AT thread for timing Cat Cams

    http://www.archerytalk.com/vb/showthread.php?t=626601

    Here is the URL to the thread on AT.

    I wonder who wrote it????

    I'm just ready for "YKW" to post on this thread and tell you it doesn't matter just shoot your bow.

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    Quote Originally Posted by gstudt View Post
    http://www.archerytalk.com/vb/showthread.php?t=626601

    Here is the URL to the thread on AT.

    I wonder who wrote it????
    I'm just ready for "YKW" to post on this thread and tell you it doesn't matter just shoot your bow.
    Duhhhh!

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