# Binary Tuning - ****** the Bottom



## fletched (May 10, 2006)

Thanks for posting your findings, I find them useful. 

As for the timing of binaries, since the cables slave the cams together, one can not catch up to the other. If one cam hits the wall first and can't move any farther, the other cam still may have some room to move. You can pull hard enough to overcome the slaving of the cams and make them both hit the wall. I set my draw stop by using a draw board and scale. I find the lowest let off point and set my draw stop at this point. If one cam is out of the valley at full draw, it will make the valley shorter. As for cam rap, I like to position the cam so that as soon as I start pulling the string, the cables are starting to travel the draw mod track. If your cam is rotated forward too much, you will have a dead spot of draw cycle before your cables start up the draw mod track. It can give a false impression that the cam rap is longer but it isn't a very useful amount. I don't always concern myself with the amount of rap but rather the effectiveness of the rap. If I want to increase the performance, I do it by putting by usable rap at the end of the draw as opposed to the front. I rather shorten the string and lengthen the draw module as lengthen the string and shorten the draw module. You pull the string to rap the cables, so you want the cables working the whole time.


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## Hozer (Jan 26, 2008)

Hey Fletched,
thanks for the detailed response. When you set your peg via the scale, do you move the peg so that it is just kissing the limb, or do you attempt to compress the o-ring while keeping the cams in the position required for the lowest holding weight?

Great observation on usable wrap. It sort of flies in the face of what lots of people are saying to do, but it makes a lot of sense to me. One way to find out - try it. I will.


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## fletched (May 10, 2006)

I push the draw stop into the limb just a little. I like to hold my bow in the valley and use the wall to help trigger the shot. If you bury into the wall to hard before you pull through the shot, you loose the advantage of the wall. 

Anytime you add a longer string to a bow, you will increase the draw length. This will usually give you more speed. But the secret is to get more speed without increasing the draw length. By positioning the cam so that it gets full use of the draw cycle is the way this is done. When you add a longer string, the cam rotation puts the cables farther a way from the draw cam. You have to draw the bow a little before the cable actually starts running it's course through the draw cam. This little area of movement is what I call the dead spot. I like to eliminate the dead spot buy rotating my cam so that the cables set closer to the draw cam so as soon as I start pulling the string, the cables are running up the draw cam. If the bow's draw length is shortened, I just put a longer draw module on the bow. This is when I stated that I like to put the draw length on the end of the cycle, not the beginning. this also makes the bow feel easier to draw since you are putting more energy into the beginning of the draw cycle where you have more pulling power. I find a bow to be more tunable this way as well. The cams don't seem to drop into let off as hard either and the bow shoots quieter. I also find that when a cam is rotated to far forward, it seems to pull against itself untill you reach enough pressure to flip the cam into rotation. This can make tuning more difficult in my opinion. The arrow needs to leave the bow when the cams are at the end of the optimum rotation, not after the cam has past that point.


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## hrchdog (Dec 13, 2004)

fletched can you post a pic of your cam and cable position to give us a better idea of what you are talking about?


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## Hozer (Jan 26, 2008)

That was my next question. Pictures?


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## fletched (May 10, 2006)

I'll get some posted in the next day or so.


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## Hozer (Jan 26, 2008)

Thanks!


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## marl59 (Jun 17, 2007)

*Cam wrap question.*

Fletched, I understand what you are saying and it makes perfect sense. Do you adjust the cam wrap by the lengthening or shortening the cables? I think I need to shorten my cables to acheive the optimum point of arrow leaving the string, When I shorten the cables what should I then do to the length of the string? Should I also shorten the string? Sorry if I'm not clear.


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## fletched (May 10, 2006)

I haven't taken any pics yet but will soon.

marl59- It depends on the draw length and poundage. On a binary cam system when you lengthen the string, it will increase the poundage and draw length. When you shorten the cables, it will do the same thing. If you shorten the string and cables both, it will lengthen the brace height, shorten the ata and preload the limbs and maintain the draw length respectively. If you lengthen the string and cables both, it will lower the brace height, lengthen the ata, and unload the limbs and maintain the draw length respectively. If you like the poundage and draw length you have now, you can shorten the cables a little and lengthen the string a little. This will change the cam position or you can lengthen the cables and shorten the string to do the same. You need to keep the ata and brace height in mind so that you can maintain or change these specs to make the bow fit and shoot better. Also keep in mind that the bow will only perform as good as the design will allow. You can make changes to help gain performance but you can't perform a miracle so don't even try. Don't use the more is better law. It doesn't apply to bows. What I mean is to stay within the boundries and perimeters. Don't go crazy and greatly alter the string lengths on a bow thinking that you found the hidden secret. The cams and limbs have an effective range. I just try to maximize it. I try to get the most of what it's bacis designs will allow. Just a little here and a little there can make a big difference once added up.


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## Hozer (Jan 26, 2008)

Thanks Fletched for the excellent tuning summary. I knew some of this stuff, but seeing it all in the different combinations and results is nice. Good to have when you are messing with your bow at 11:30 at night and you can't think straight!


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## marl59 (Jun 17, 2007)

Yes, Thanks Fletched. I just got my bow shooting bullet holes today so I'm not going to change anything for a coupe of weeks. I shot my second best score ever last Monday night even though it wasn't tuned very well.Thanks for the clear explanations. I realize also what you said about not overdoing the tweak. These bows are built for the masses and work well right out of the box. But with a little more time spent and some trial and error they can be made to work a little more efficiently. I'm up for that. Thanks again for your direction, I'll post my results after making some adjustments. "08" 101st Airborne.


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## meyerske (Dec 26, 2004)

Hozer said:


> Those of you who follow binary tuning know this isn't right.
> 
> But for those who are interested in tuning binaries, maybe you'd be interested in reading about my experience and can offer some thoughts.
> 
> ...


Interesting. Why not just install a draw stop on both the top and bottom cams? (at least for Elite's bows you can do this)


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## fletched (May 10, 2006)

meyerske said:


> Interesting. Why not just install a draw stop on both the top and bottom cams? (at least for Elite's bows you can do this)


A draw stop on top and bottom would serve no purpose. Since the cams are slaved together, when you stop one cam, the other stops with it.


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## meyerske (Dec 26, 2004)

fletched said:


> A draw stop on top and bottom would serve no purpose. Since the cams are slaved together, when you stop one cam, the other stops with it.


No, that's not quite right. When the top cam stops due to the draw stop, the bottom cam can still move slightly since there is no hard stop for it. Try it. Pull to full draw, then pull a little harder and you'll see what I mean. The new Elites have a draw stop on each cam.


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## fletched (May 10, 2006)

meyerske said:


> No, that's not quite right. When the top cam stops due to the draw stop, the bottom cam can still move slightly since there is no hard stop for it. Try it. Pull to full draw, then pull a little harder and you'll see what I mean. The new Elites have a draw stop on each cam.


Uder normal conditions, the one draw stop is fine. I am sure if you pull over hard, it can make the bottom move some. The problem you have with two stops is people not getting them set exactly the same which can defeat the purpose.


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## soonerboy (Sep 6, 2004)

This is GREAT!!! stuff. Would love to see the pictures of your cam.


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## jtb1967 (Sep 22, 2004)

Yes, detailed photos are a must!


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## mattcrov (Apr 12, 2006)

Thanks everyone for the tips, I have just got a Tribute 2006 and am waiting on some new strings from Deeslin, am gonna put a draw board together and get her fine tuned. Pics would be great guys, if you can, of cams etc

cheers :darkbeer:


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## soonerboy (Sep 6, 2004)

fletched---you the MAN. I have an 08 Constitution 27" draw that I just could not get to group. fletched clicked a light on for me about cable rap. I put a 1.5" shorter string on the bow, the 29" mods, and took 10 twists out of the cables. Bingo, I now have a bow that is 27.25" draw, 53#(I lost 7# of draw weight), but most importantly---It groups. I think the key is cutting down that "Dead Zone" fletched talked about.


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