# String Length Formula Sheets



## EPLC (May 21, 2002)

The attached 3 sheets show calculated starting string lengths based on 1.25%, 1.5% and 1.75% over finished lengths. You can print them from here.


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## CherryJu1ce (Feb 25, 2005)

But what is the purpose of having this information? Whenever I make a set of strings, I simply make my strings and cables 1/4" longer than desired finished length, and twist from there. I've made countless sets, and have yet to make a string or cable that hasn't come out perfect in terms of length.


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## Stash (Jun 1, 2002)

Seems to me a lot of wasted effort to produce these charts. Doesn't include odd string lengths or cable lengths, and how do you know if your string needs to be 1.25 or 1.5 or 1.75" longer than spec?

You could just pull out your trust dollar store calculator and punch in the numbers on the spot.


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## Gunner7800 (Jul 11, 2007)

What number do you use to account for string length lost for each twist? 

Obviously you're going to have to have more twists in a 1.75% string than a 1.25% string to get it to the finished length.


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## Bow pro (Mar 4, 2009)

Man come on guy's he's just tryn to help everyone out....cut him some slack. The chart's he posted will get you really close to ball park what you need to start with. The diff. in the chart's is a general way of how you choose to build string's(how many twist per inch) ....the way i'm reading it anyway.


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## Gunner7800 (Jul 11, 2007)

Bow pro said:


> Man come on guy's he's just tryn to help everyone out....cut him some slack. The chart's he posted will get you really close to ball park what you need to start with. The diff. in the chart's is a general way of how you choose to build string's(how many twist per inch) ....the way i'm reading it anyway.


That's how I was thinking the tpi would work. But I'm pretty new at this so I wasn't sure.


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## Spotshooter2 (Oct 23, 2003)

Cherryjuice , if you are only adding 1/4 to your strings you arent putting very many twists in them then.


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## dwagoner (Sep 27, 2007)

Bow pro said:


> Man come on guy's he's just tryn to help everyone out....cut him some slack. .


AGREE but i dont think there trying to be mean

the chart i have and use calculates for twist ratio also and that added length to set the posts


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## Limey (May 6, 2005)

Spotshooter2 said:


> Cherryjuice , if you are only adding 1/4 to your strings you arent putting very many twists in them then.


That will depend on the string length.

It will be a lot on a floating yoke cable and not many on a one cam string.


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## Limey (May 6, 2005)

EPLC said:


> The attached 3 sheets show calculated starting string lengths based on 1.25%, 1.5% and 1.75% over finished lengths. You can print them from here.


By the way thanks Paul.

Any thing that reduces my "duck up factor" is appreciateed :darkbeer:


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## MR.B (Jan 14, 2006)

Spotshooter2 said:


> Cherryjuice , if you are only adding 1/4 to your strings you arent putting very many twists in them then.


not to mention that the string and cable must not look very uniform


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## yakstone (Jun 30, 2008)

Thanks for the sheets, well done!


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## EPLC (May 21, 2002)

CherryJu1ce said:


> But what is the purpose of having this information? Whenever I make a set of strings, I simply make my strings and cables 1/4" longer than desired finished length, and twist from there. I've made countless sets, and have yet to make a string or cable that hasn't come out perfect in terms of length.


I'm impressed...


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## jcmorgan31 (Nov 9, 2005)

I prefer to have the same twist rate whether it is an 18" Limb Driver cable or a 90" single cam string. Building them all 1/4" long won't accomplish this and twisting them back to length is't the best way to accomplish this. 

EPLC - I assume your layout jig is 1/4" posts?

I have an excel spreadsheet that does what your charts do, but I can put in specific desired finished lengths and it gives me my starting jig settings. My layout posts are 3/8" so I had to modifiy the original formula that was built for 1/4" posts.


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## EPLC (May 21, 2002)

Stash said:


> Seems to me a lot of wasted effort to produce these charts. Doesn't include odd string lengths or cable lengths, and how do you know if your string needs to be 1.25 or 1.5 or 1.75" longer than spec?
> 
> You could just pull out your trust dollar store calculator and punch in the numbers on the spot.


First, it took about 5 minutes to create the chart. Second, the chart covers a wide range of lengths in 1-inch increments so if you have an inbetween number you can easilly figure out the setting. Third, the 1.25, 1.5 and 1.75 charts were provided as options. Many here have said they use the factor of 1.2 to make their strings, but some folks may want more twists per inch so they would use the 1.5 or 1.75 chart. 

Sorry for being such a bore.


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## jcmorgan31 (Nov 9, 2005)

EPLC said:


> First, it took about 5 minutes to creat the chart. Second, the chart covers a wide range of lengths in 1-inch increments so if you have an inbetween number you can easilly figure out the setting. Third, the 1.25, 1.5 and 1.75 charts were provided as options. Many here have said they use the factor of 1.2 to make their strings, but some folks may want more twists per inch so they would use the 1.5 or 1.75 chart.
> 
> Sorry for being such a bore.



This thread is a great example of why AT isn't as much "archers helping archers" as it used to be. A guy posts some good information to help out those that can use it and then the complaining begins. 

If you don't need it, then move on.

:darkbeer:


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## EPLC (May 21, 2002)

jcmorgan31 said:


> I prefer to have the same twist rate whether it is an 18" Limb Driver cable or a 90" single cam string. Building them all 1/4" long won't accomplish this and twisting them back to length is't the best way to accomplish this.
> 
> EPLC - I assume your layout jig is 1/4" posts?
> 
> I have an excel spreadsheet that does what your charts do, but I can put in specific desired finished lengths and it gives me my starting jig settings. My layout posts are 3/8" so I had to modifiy the original formula that was built for 1/4" posts.


Yes, they are based on 1/4" posts. This is also a spreadsheet that I can enter the factor and it calculates the jig settings. I posted printables based on 3 different factors so folks could use the data if they so choose based on their preference.


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## EPLC (May 21, 2002)

Gunner7800 said:


> What number do you use to account for string length lost for each twist?
> 
> Obviously you're going to have to have more twists in a 1.75% string than a 1.25% string to get it to the finished length.


Gunner, some folks may prefer more or less twists than others, the sheet you would use would be based on personal preference. So... if you like more twists use the 1.5 or 1.75, less use the 1.25...


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## Green River (May 13, 2006)

I don't mean to sound like a stick in the mud either but I was comparing some of the lengths on the chart with the formula I use. Adding 1.75" or even 1.25" to a 100" string sounds very excessive to me, are you sure you don't mean 1.25, 1.5, or 1.75 as that many inches per twist? Because if you twist a bow string 1 turn it will only shorten it about .010", 12 turns = about .120" ( aprox. 1/8"). If you add 1.25" to a 100" string I guarantee you will have to tie knots in it to get it to the right length. Again not trying to sling mud here just want to make sure I'm understanding what the chart reads.


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## CherryJu1ce (Feb 25, 2005)

Bow pro said:


> Man come on guy's he's just tryn to help everyone out....cut him some slack. The chart's he posted will get you really close to ball park what you need to start with. The diff. in the chart's is a general way of how you choose to build string's(how many twist per inch) ....the way i'm reading it anyway.


I'm not trying to be condescending or confrontational. I genuinely don't understand the reason behind charts such as this. 



Spotshooter2 said:


> Cherryjuice , if you are only adding 1/4 to your strings you arent putting very many twists in them then.


10 twists per cable, 15 per string. So no, I suppose it's not very many. 



Limey said:


> That will depend on the string length.
> 
> It will be a lot on a floating yoke cable and not many on a one cam string.


I don't make one cam strings, simply because I have no use for single cam bows. 



MR.B said:


> not to mention that the string and cable must not look very uniform


I put the same number of twists in each cable and only 5 more in the string. They actually look very uniform. 



EPLC said:


> I'm impressed...


Again, not trying to be confrontational. 



jcmorgan31 said:


> This thread is a great example of why AT isn't as much "archers helping archers" as it used to be. A guy posts some good information to help out those that can use it and then the complaining begins.
> 
> If you don't need it, then move on.
> 
> :darkbeer:


I'm trying to learn something here. If I were making a 105" string, there's no way I would even think to make it a full inch and a half longer. How many twists are required to take up that length?


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## ex-wolverine (Dec 31, 2004)

*This is what my formula comes out to be*

You can see that Im almost one inch over...My strings come to within 1/16 on an inch when served...and I dont twist or untwist to get my desired length...EL was trying to be helpful...For those of us that are OCD when it comes to String building...Charts can come in handy

Example

*String Length *=105" * Twists*=78.75 *Jig Post Setting *=105.945







CherryJu1ce said:


> I'm not trying to be condescending or confrontational. I genuinely don't understand the reason behind charts such as this. 10 twists per cable, 15 per string. So no, I suppose it's not very many. I don't make one cam strings, simply because I have no use for single cam bows. I put the same number of twists in each cable and only 5 more in the string. They actually look very uniform. Again, not trying to be confrontational. I'm trying to learn something here. If I were making a 105" string, there's no way I would even think to make it a full inch and a half longer. How many twists are required to take up that length?


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## CherryJu1ce (Feb 25, 2005)

ex-wolverine said:


> You can see that Im almost one inch over...My strings come to within 1/16 on an inch when served...and I dont twist or untwist to get my desired length...EL was trying to be helpful...For those of us that are OCD when it comes to String building...Charts can come in handy
> 
> Example
> 
> *String Length *=105" * Twists*=78.75 *Jig Post Setting *=105.945


Oh my Lord! Almost 80 twists!?!


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## ex-wolverine (Dec 31, 2004)

*The longer the string the more twists*



CherryJu1ce said:


> Oh my Lord! Almost 80 twists!?!


Here is a single CAM string PIC for ya...Or you can go to my profile and look at my strings...:darkbeer: they about as uniform of a twist as you will find


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## ericjames (Mar 4, 2009)

ex-wolverine said:


> Here is a single CAM string PIC for ya...Or you can go to my profile and look at my strings...:darkbeer: they about as uniform of a twist as you will find


Great looking strings!


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## Gunner7800 (Jul 11, 2007)

EPLC said:


> Gunner, some folks may prefer more or less twists than others, the sheet you would use would be based on personal preference. So... if you like more twists use the 1.5 or 1.75, less use the 1.25...


Gotcha, thanks EP.


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## Stash (Jun 1, 2002)

I wasn't trying to be confrontational either. I just don't see the value of downloading a chart and printing and storing it with your stringmaking supplies over simply using a calculator to add 1.5% to a number as you need it.

How about some information regarding what percentage you need to make the string longer for varying numbers of twists per inch? Say you have a 100" one-cam string and like 1/2 twist per inch. That's 50 twists - how much does that shorten a string?


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## EPLC (May 21, 2002)

Stash said:


> I wasn't trying to be confrontational either. I just don't see the value of downloading a chart and printing and storing it with your stringmaking supplies over simply using a calculator to add 1.5% to a number as you need it.
> 
> How about some information regarding what percentage you need to make the string longer for varying numbers of twists per inch? Say you have a 100" one-cam string and like 1/2 twist per inch. That's 50 twists - how much does that shorten a string?


Why don't you just figure that out on your little calculator?


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## jdduffy (Sep 19, 2006)

all the settings for 60" strings have the jig set at 60",am I reading this wrong ?


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## EPLC (May 21, 2002)

jdduffy said:


> all the settings for 60" strings have the jig set at 60",am I reading this wrong ?


You are correct, there was an error on the 60" calculation. The fixes are attached.


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## Spotshooter2 (Oct 23, 2003)

> If you add 1.25" to a 100" string I guarantee you will have to tie knots in it to get it to the right length. Again not trying to sling mud here just want to make sure I'm understanding what the chart reads.


 Not really Green River , you have to remember that as you add more twists they start to take more length away with each twists. EPLC and I make our strings quite a bit the same actually. He adds a few more twists than I do but overall not that many. For me on a 100 inch string I times it by .012 which adds another 1.20 to the initial length of the string. I figure the amount of twists I need to add at being 2/3 of the total finished string length , so on a 100 inch string I would be adding 66.6 twists to the string or rounded to 67 twists. This gives me a twist ratio of between 1.3 to 1.5 inches per twists. It sounds like a lot of twists but on a 100 inch string it isn't. This way has been working well for me on my Little Jon string jig where I can get the tension to 300 lbs. Now if you can't get that amount of tension then my or EPLC's method might not work for you.


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## EPLC (May 21, 2002)

Green River said:


> ... If you add 1.25" to a 100" string I guarantee you will have to tie knots in it to get it to the right length. Again not trying to sling mud here just want to make sure I'm understanding what the chart reads.


Actually these numbers work out quite well and produce +/- 1.5 twists per inch. I'd be curious to see some of the strings that are made with much less extra to start with... 

To answer your question: The chart contains the finished string length, the amount added to the final length (based on 1.25, 1.50 or 1.75) and the jig setting, which is the first two numbers added together.


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## Spotshooter2 (Oct 23, 2003)

> Actually these numbers work out quite well and produce +/- 1.5 twists per inch


 EPLC, did you get your numbers turned around and really mean to say 1 twist in 1.5 inches?


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## EPLC (May 21, 2002)

Spotshooter2 said:


> EPLC, did you get your numbers turned around and really mean to say 1 twist in 1.5 inches?


No... it is what ever it is. This 104" string was made @ 1.25 over finished size and twisted down to spec. You're looking at the string under aproximately 100# pressure.


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## EPLC (May 21, 2002)

The box in the picture is about 1" so how many twists do you see? Since I don't really count my twists I use a visual reference for this. Depending on how you look at it, this would be about 1 to 1.5 per inch. From the start of the blue to the start of the next blue is about 1" but you also have a full blue and a half yellow facing you in the same inch. I'm using the blue/yellow visual for what I want to see over a one inch span.


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## EPLC (May 21, 2002)

So... all of this got me curious about how many actual twists there are so I just counted them. Over a 102" span there are 100 blue's and 100 yellow's facing you. I believe that would be 100 full twists.


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## redman (Feb 22, 2003)

great info


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## r49740 (Dec 7, 2006)

Great info. I am still learning so bear with me if you don't mind. I used the charts above and wanted to compare to waht I came up with to see how closse I am to understanding what is being said. So for the following lengths listed on 3 different setups, what would I lay the initial jig posts at? I have the jurassic jig that I serve the loops according to GRIV's method, then I move it to a stretcher to stretch and burnish under 300 lbs. Then I back it to 100 lbs, double check length, then back to 300 to serve.

Final Lengths
String Control Cable Buss Cable
60.50 45.25 42.75
56.25 42.50 40
54.75 39.25 37


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## r49740 (Dec 7, 2006)

ttt


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## UltraEliteLover (Sep 5, 2009)

*string type*

is this for 452x material. any idea what I would use for 8125


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## dillio67 (Oct 1, 2004)

*Post settings*

use the same for 8125


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