Author Topic: spectra bowstrings  (Read 8699 times)

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Offline jeffp51

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Re: spectra bowstrings
« Reply #15 on: December 10, 2015, 01:44:35 pm »
every how-to I have seen on endless loop strings require a funky jig.  Is there a way to do this that I am missing?

I did in fact buy the fishing line out of convenience--and to test the stuff out. If it is 65 lb test, how do you calculate how many strands you need for a give bow weight?  10x the test strength?  If a bow is 50lb, then theoretically one 65# line would hold it at brace, although would not be strong enough to withstand the tension of an arrow shot, right?  Is there a TBB chapter on this?

Offline PatM

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Re: spectra bowstrings
« Reply #16 on: December 10, 2015, 02:16:49 pm »
Make a less funky jig. It's not that hard.   You just need to establish length and a means to  spread the larger  loop of string to give room to serve the end loops.
 Plenty of recommendations as to the safety margin needed for bowstrings relative to bow weight and material being used.

Offline jeffp51

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Re: spectra bowstrings
« Reply #17 on: December 11, 2015, 03:19:55 am »
I'm a little embarassed I have been making endless loop style strings with artificial sinew exclusively since I began making bows 12+years ago. Do yall think this type of low stretch material in an endless loop style would maje any notable improvement in performance?

that is kind of what I want to experiment with. The TBBII chapter on string making says that a 20 grain reduction in mass will result in about 1fps improvement in cast.  If that is true--the B-50 string I made is 1380 grain, but the 10-strand spectra line I just made is only 612 grain.  I am a little dubious, but it suggests that I should see an improvement of about 38 fps over the other string.  I have no chronograph, but does anyone have experience to back that up?

Offline Pappy

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Re: spectra bowstrings
« Reply #18 on: December 11, 2015, 06:46:48 am »
Not sure how much ,but assure you the performance is better with fast flight, less stretch/less arm slap and quieter  for a bonus.  :)
 Pappy
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Offline BowEd

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Re: spectra bowstrings
« Reply #19 on: December 11, 2015, 07:10:51 am »
Ditto...I can see the speed difference with the naked eye practically.The difference for me between 12 strands of B50 and 9 strands of fast flight plus was around 8 feet per second.That's a fact.Even with my sometimes mobile anchor....lol.
I agree with you Chris but he has to get his initial thickness of his serving first.
BowEd
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Ed

Offline Badger

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Re: spectra bowstrings
« Reply #20 on: December 11, 2015, 09:13:22 am »
 Jeffrey, are you sure you weighed your strings right? Thats about 10 times what I would expect.

Offline jeffp51

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Re: spectra bowstrings
« Reply #21 on: December 11, 2015, 10:27:07 am »
Jeffrey, are you sure you weighed your strings right? Thats about 10 times what I would expect.
it seemed heavy to me too. I even re-calibrated my grain scale and still got the same weight.  1382gn for a 12 or 14 strand B-50  flemish-twist string with about 7 inches of serving and a paper nock point. Am I just a really bad string maker?

Offline JoJoDapyro

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Re: spectra bowstrings
« Reply #22 on: December 11, 2015, 10:28:07 am »
Jeffrey, are you sure you weighed your strings right? Thats about 10 times what I would expect.
Are you looking for grams Badger? It would be an 89 gram string.
If you always do what you always did you'll always get what you always got.
27 inch draw, right handed. Bow building and Knapping.

Offline jeffp51

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Re: spectra bowstrings
« Reply #23 on: December 11, 2015, 10:31:24 am »
Wait, no--on second thought--I am probably just getting old and my eyes are giving out.  There is a little, tiny decimal point there-so Badger, you are right.  the string is exactly 10 times lighter at 138.2 grains.  I don't know if I feel better now or worse :-[

Offline JoJoDapyro

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Re: spectra bowstrings
« Reply #24 on: December 11, 2015, 10:33:15 am »
Wait, no--on second thought--I am probably just getting old and my eyes are giving out.  There is a little, tiny decimal point there-so Badger, you are right.  the string is exactly 10 times lighter at 138.2 grains.  I don't know if I feel better now or worse :-[
Stupid decimals!  >:D
If you always do what you always did you'll always get what you always got.
27 inch draw, right handed. Bow building and Knapping.

Offline lebhuntfish

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Re: spectra bowstrings
« Reply #25 on: December 11, 2015, 10:46:55 am »
Jeff, I've made several strings out of the power pro 50 and 65 lb test line. 8 to 10 strands is enough for just about any bow I've ever made it for. I tend to use 12 strands which is normally over kill but I like the size after I pad the loops with b50. I've done a double serving using the spectra as the first layer then my normal serving as the top layer. I've had trouble with that, serving it by hand. But with a serving tool it comes out nicely. My new favorite serving material is halo serving. With that all I need to do is a single layer and I'm good, as long as I make at least a 12 strand string. It's a bit thicker and it says it's specifically designed for finger shooters. But you will want to have a serving tool for sure.

The string I made for my Fury trade bow was made with power pro. And it's on every bow I shoot. It's about 9 to 12 dollars for 350 yards, easy obtainable and if I need some I can just run to town and pick something up. I'm going to give monofilament fishing line a go for a serving to. I see clay hays do it in one of his YouTube videos.

Patrick
« Last Edit: December 11, 2015, 10:51:56 am by lebhuntfish »
Once an Eagle Scout, always an Eagle Scout!

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Building a bow has been the most rewarding, peaceful, and frustrating things I have ever made with my own two hands!

Offline lebhuntfish

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Re: spectra bowstrings
« Reply #26 on: December 11, 2015, 10:53:57 am »
Bee's wax is the secret.

+1, that's the only way! Store bought string wax dosent work, trust me!
Patrick
Once an Eagle Scout, always an Eagle Scout!

Missouri, where all the best wood is! Well maybe not the straightest!

Building a bow has been the most rewarding, peaceful, and frustrating things I have ever made with my own two hands!

Offline Badger

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Re: spectra bowstrings
« Reply #27 on: December 11, 2015, 12:15:46 pm »
  I like the look of linen strings and the no stretch qualities they have. I use 4 strands of d97 and 6 strands of linen in my personnal strings now. It gives me a decent diameter and a good safety factor.

Offline PatM

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Re: spectra bowstrings
« Reply #28 on: December 11, 2015, 12:51:51 pm »
I honestly prefer the fishing line over proper bowstring. It's designed to be more abrasion resistant and has a harder finish already on it.

Offline loon

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Re: spectra bowstrings
« Reply #29 on: December 18, 2015, 05:27:31 pm »
Is there braided spectra or similar cord suitable for bowstrings? Seems like dyneema and spectra are polyethylene but dacron is polyester.

It would be much easier to just tie a knot in the end using relatively thick braided knot than to make a flemish twist or endless loop string. I got a nice looking pvc bow from Tommy Hard which came with such a string (dacron), with knots on the ends.