Primitive Archer

Main Discussion Area => Bows => Topic started by: oic0 on May 13, 2012, 06:40:34 pm

Title: Is there a formula for brace height?
Post by: oic0 on May 13, 2012, 06:40:34 pm
Is there a formula for how many inches shorter than my nock to nock the string needs to be to get X brace height? Have a decent tiller, ready to shoot, I'm running 3 less than nock to nock and only have about 1 inch :( That of course slaps the piss out of my hand and puts some wobble on the arrow. If 3 inches gets me an inch, do I need a string like 12 - 14 inches short to get a shootable brace height? or am I doing something wrong here.
Title: Re: Is there a formula for brace height?
Post by: beetlebailey1977 on May 13, 2012, 06:54:45 pm
Normally a two to three inch shorter string will get you close to what you need but that can vary from bow to bow.  I choose on a selfbow to brace as low as possible and still clear my feathers.  For me that is at least 6" or more from the back of the grip.
Title: Re: Is there a formula for brace height?
Post by: George Tsoukalas on May 13, 2012, 07:14:02 pm
If it is a Flemish string then twist it. Jawge
Title: Re: Is there a formula for brace height?
Post by: PEARL DRUMS on May 13, 2012, 07:15:28 pm
If its a flemish string twist it up until you get to 5 1/4" brace. Then shoot it 2-3 times, if your arrows fly like crap and is loud twist it 4-5 more times and repeat until your bow quiets down and your arrows fly good. Arm slap can be from a bunch of things, not just brace height. 
Title: Re: Is there a formula for brace height?
Post by: Badger on May 13, 2012, 09:02:56 pm
  3" should be enough, you may have the wrong string material or not enough strands of string. I never go more than 4" on a long bow.
Title: Re: Is there a formula for brace height?
Post by: oic0 on May 13, 2012, 09:33:08 pm
I didnt think this 500+lb cord would stretch so much with so little weight on it. It was stretching over an inch. I need some better string.

I got it to this much brace height with yalls suggestion of 2 or 3 inches. The fletchings are still hitting while its on the string, is that ok?. Maybe I need to lean more towards the 3" and less towards the two. The string is catfish line from the baitshop. Twisted nylon with tar on it or some such. Should I twist that on down / shorten it or look in to getting a real string? or run with what I have? The arrows have a bit of wobble to em in flight. Like the tail end gets kicked up as it leaves the bow.

(http://i48.tinypic.com/11wg86q.jpg)
Title: Re: Is there a formula for brace height?
Post by: PEARL DRUMS on May 13, 2012, 09:37:35 pm
You need a real string.
Title: Re: Is there a formula for brace height?
Post by: George Tsoukalas on May 13, 2012, 09:43:16 pm
Most bowstrings are made from dacron B 50. That is what  recommend so you need to order one from a sponsor that is  inches shorter than the nock to nock distance of your bow or you need to make one. I don't know where there is a sponsor list.  Jawge
Title: Re: Is there a formula for brace height?
Post by: beetlebailey1977 on May 13, 2012, 10:44:43 pm
I agree......get some bowsring material.......can't skimp on that.  If you do you may damage your bow or injure yourself.  Get some B-50 or B-55 material.
Title: Re: Is there a formula for brace height?
Post by: doggonemess on May 13, 2012, 11:01:04 pm
Until I got B-50 from Amazon, I tried lots of different materials for string, and found that the absolute worst was cotton, followed by hemp. My favorite material was 'kite string', but it stretched like crazy. I found that upholstery thread works great - it's very string and incredibly thin, and easy to find. Any fabric / sewing store will have it. It does tear up your fingers, though.

In the end, I'm so happy that I got B-50. It even came pre-waxed.
Title: Re: Is there a formula for brace height?
Post by: lesken2011 on May 14, 2012, 12:21:57 am
One of the old 1940's-50's bow making articles in Popular Mechanics described the use of upholstery thread for the string, but dacron is what I learned on and still use some along with fast flight. To me, the bow design has a lot to do with the best brace height. I had a friend that had a recurve that came with a recommended brace height of 7 1/2 inches which seemed like a lot, but worked well for that design. If I am not sure, I start with a fistmele and the adjust from  there depending on arrow flight, etc. Higher brace heights generally are a little more forgiving, for me at least, but you give up some cast and arrow speed. Arrow spine and feather length are also considerations. IMHO
Title: Re: Is there a formula for brace height?
Post by: Stiks-N-Strings on May 14, 2012, 01:13:50 am
oic0

 If you send me your addy and the length of string you need I'll twist you up a b-50 with one loop and you can learn how to tie a bowyers knot (also called a timber hitch) on the other end
Title: Re: Is there a formula for brace height?
Post by: carpentertimw on May 14, 2012, 12:10:20 pm
Your main problem with that string is that nylon stretches a ridiculous amount. You should get some B-50 or Fast Flight instead.
Title: Re: Is there a formula for brace height?
Post by: johnston on May 14, 2012, 12:22:13 pm
I will no doubt catch some flack for saying this but...My once surgeon level hands are only
a shadow of their former glory and it is tough for me to twist up strings and it hurts like
hell. I asked halfeye about this cause he has hand trouble also. His advice was artificial
sinew (available from 3Rivers).
Twist with a drill, double overhand loop on the top and bowyers knot on the bottom.Works
like a charm and if it is good enough for Rich........

Lane
Title: Re: Is there a formula for brace height?
Post by: oic0 on May 14, 2012, 11:47:28 pm
Picked up a dacron flemish string this morning. 3 inches shorter than nock to nock (56.5"). Soon as it comes in I'm going to shoot the heck out of it till I stop sucking at archery :D

oic0

 If you send me your addy and the length of string you need I'll twist you up a b-50 with one loop and you can learn how to tie a bowyers knot (also called a timber hitch) on the other end

Thats what I get for not paying attention to my thread!. The one I bought was only $8 though and I would have felt bad giving you only that much for postage and the trouble of mailing it. Thank you for the offer though.