The Arbalist Guild

Would you like to react to this message? Create an account in a few clicks or log in to continue.

Crossbows - Everything about Building, Modding, and Using your Crossbow Gear

Latest topics

» Look what the smith sent
by stuckinthemud1 Fri Jul 31, 2020 1:35 pm

» Covid 19 and crossbow builders
by kenh Thu Jul 30, 2020 10:22 am

» Crossbow accuracy
by Geezer Thu Jul 30, 2020 7:51 am

» How do you feel about miniature crossbows?
by El Zurdo Wed Jul 29, 2020 7:21 am

» Claw crossbow prototype
by Dennis Greenaway Tue Jul 28, 2020 10:34 pm

» how to Build a non Chinese repeating crossbow?
by Dennis Greenaway Tue Jul 28, 2020 4:05 pm

» Just finished my windlass crossbow!
by Dennis Greenaway Tue Jul 28, 2020 4:01 pm

» Sinew backed crossbow prod tillering. Update and questions.
by stuckinthemud1 Tue Jul 28, 2020 2:43 am

» snakeskin not birch bark on composite bows in medieval period
by Cornerstone Mon Jul 27, 2020 3:50 pm

» two axle mechanism makers/accurate plans?
by stuckinthemud1 Wed Jul 22, 2020 10:34 am

» Anyone make their own bolts?
by MPDVM Tue Jul 07, 2020 11:14 pm

» ash lath and pin-lock crossbow
by stuckinthemud1 Sat Jul 04, 2020 2:42 am

» Stonebow Buildalong
by banuvatt Thu Jun 25, 2020 9:00 pm

» How to Attach a PVC Prod to a Stock?
by banuvatt Tue Jun 02, 2020 8:22 am

» finally started my first composite bow
by stuckinthemud1 Fri May 29, 2020 12:40 am

» AMAZING MINI CROSSBOW code name KillCovid-19
by El Zurdo Thu May 21, 2020 3:14 am

» Draw length ash lath
by banuvatt Thu Apr 23, 2020 9:47 am

» Would like to buy or rent a Han Chinese Trigger
by PierreC Thu Apr 23, 2020 2:37 am

» High Draw Weight PVC Crossbow Build
by banuvatt Fri Apr 17, 2020 3:07 pm

» Universal standard Crossbow nut
by Fangbows Tue Apr 14, 2020 11:57 pm

» Making Chinese 240lb Han Crossbow
by banuvatt Tue Apr 07, 2020 8:40 am

» Goat’s foot lever drawings
by Geezer Mon Mar 23, 2020 9:18 am

» First Build
by banuvatt Thu Mar 05, 2020 7:14 pm

» How to Test the Breaking Strength of a Matieral for a Bow String?
by banuvatt Thu Mar 05, 2020 4:06 am

» Can anyone help me ID this?
by Geezer Sat Jan 25, 2020 4:30 pm


    affects of brace height

    avatar
    panne
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows

    Posts : 46
    Join date : 2012-10-21
    Location : abbeville, la

    affects of brace height Empty affects of brace height

    Post by panne on Wed Dec 12, 2012 9:46 am

    looking for some insight on how different brace heights affect performance on a crossbow, without changing the prod mounting and trigger locations, using the same weight bolt.

    thanks,
    panne
    Todd the archer
    Todd the archer
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!

    Posts : 581
    Join date : 2010-02-25
    Age : 58
    Location : sellersville,pa.

    affects of brace height Empty Re: affects of brace height

    Post by Todd the archer on Wed Dec 12, 2012 2:26 pm

    Lower brace height gives a longer power stroke and thus faster speed. However most crossbows we build using a one piece prod have the prod canted. Braced too low and you increase string drag and the string might jump off the nocks, too high and the string might travel across the deck too high and could cause a miss fire.



    Todd
    avatar
    panne
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows

    Posts : 46
    Join date : 2012-10-21
    Location : abbeville, la

    affects of brace height Empty Re: affects of brace height

    Post by panne on Thu Dec 13, 2012 7:24 am

    so if the string pressure and brace height is correct the string should have enough pressure in the unspanned position to keep the string in contact with the rail through the whole draw length, since the string pressure will be decreased in the spanned position, directly proportional to the degree of prod angle? so if it misfires, lowering the brace height in small increments to increase the string pressure should help correct misfires, but will also slow the FPS due to the increase in drag as it moves forward?
    mac
    mac
    Master Weaponsmith
    Master Weaponsmith

    Posts : 560
    Join date : 2010-12-23
    Location : Near Philly USA

    affects of brace height Empty Re: affects of brace height

    Post by mac on Thu Dec 13, 2012 9:52 am

    Panne,

    There are many different ways that a bolt can "misfire". So long as the center of the string travels in a way that will keep it pressed against the center of the end of the bolt, it does not much matter what the brace height is.

    The danger which Todd mentioned is that a low brace height can sometimes cause the string loops to get over the upper shoulders of the nocks. This will cause the string to leave the bow, and the prod limbs to continue traveling forward unchecked. The resulting stress reversal is decidedly prejudicial to the life of the prod. Indeed, an organic prod might fail right then and there. Therefore, this particular mode of "misfire" should be guarded against.

    In general, I think you will find that if you lower the brace height a bit, the increase in friction of the string on the top of the tiller is more than compensated for by the longer stroke. That is, so long as the string still has tension in its resting position.

    Mac

    Sponsored content

    affects of brace height Empty Re: affects of brace height

    Post by Sponsored content


      Current date/time is Mon Aug 03, 2020 3:31 pm