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

Latest topics

» Chinese crossbow with auxiliary string?
by c sitas Today at 8:57 pm

» Crusader crossbow
by c sitas Yesterday at 9:41 pm

» Yet another one
by Daniel Levesque Yesterday at 11:51 am

» Whamo showed up, prod replacement ideas
by kenh Mon Jun 19, 2017 4:25 pm

» Renaissance Sporting crossbow
by tony a Mon Jun 19, 2017 2:10 am

» 15th century saxon prods
by Geezer Sun Jun 18, 2017 10:46 pm

» loose laminate issues
by c sitas Sun Jun 18, 2017 8:42 am

» Of Bows and Torsion Engines
by c sitas Fri Jun 16, 2017 2:55 pm

» My second crossbow
by Daniel Levesque Fri Jun 16, 2017 10:48 am

» Need to locate Windlass Crossbow, pre 1600, in Rome, Venice, or Florence
by 8fingers Tue Jun 13, 2017 11:24 pm

» Crossbow Projectiles
by Geezer Tue Jun 13, 2017 8:10 pm

» Greetings!
by OnlyHuman Mon Jun 12, 2017 7:40 am

» Anyone know what this is?
by Yuki23emma Sun Jun 11, 2017 2:54 pm

» Prod specs
by Onager Lovac Mon Jun 05, 2017 4:25 pm

» Finished Crossbow
by kenh Sat Jun 03, 2017 8:34 pm

» The Arbalist Guild - Around the World
by Turnigy Fri Jun 02, 2017 1:25 pm

» Reverse draw "compound" build
by Turnigy Fri Jun 02, 2017 1:20 pm

» Casting Resource
by White Oak Wed May 31, 2017 2:28 am

» The Road so far......
by White Oak Mon May 29, 2017 7:17 am

» GLOSSARY OF TERMS
by Onager Lovac Wed May 24, 2017 6:41 pm

» Hello from Maine
by White Oak Sun May 21, 2017 11:06 pm

» Leonardo Da Vinci string with suport-rolls
by Oppenheimer Tue May 16, 2017 11:40 am

» Compact repeating compound project
by Phil Abrahams Mon May 08, 2017 2:10 pm

» Trying to reduce the power stroke in my next project
by octavioaugusto.oliveira Thu Apr 27, 2017 1:27 pm

» Its good to be back!!
by Juan galeano Tue Apr 25, 2017 9:31 am


    Fiberglass prod draw length

    Share
    avatar
    woodsmith
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows

    Posts : 16
    Join date : 2013-11-07
    Age : 62
    Location : Kitchener, ON, Canada

    Fiberglass prod draw length

    Post by woodsmith on Sun Dec 29, 2013 11:58 am

    Does anyone know the draw lengths for the Taiwanese fiberglass prods, the 80lb and the 150lb ?
    I'm starting a build based on a PVC prod but would like to change it out later for a stronger prod.
    Thanks
    avatar
    Geezer
    Master Crossbowyer
    Master Crossbowyer

    Posts : 928
    Join date : 2010-01-12
    Age : 69
    Location : Austin, Texas, USA

    Re: Fiberglass prod draw length

    Post by Geezer on Sun Dec 29, 2013 5:07 pm

    If we're on the same page, the Chinese 150 lb. fiberglass prods (often closer to 125) are essentially knock-offs of the old Barnett Panther and later "San Marino' crossbows.  approx 28 inches from end to end.  They'll tolerate @ 8 inches of draw from 3.5 in. brace... maybe 9 inches, but I never went for more than 8.  Does anybody else have more info?  Geezer.

    phuphuphnik
    Workshop Savvy

    Did you see my tool collection?


    Workshop SavvyDid you see my tool collection?

    Posts : 146
    Join date : 2013-12-02
    Location : The wastes West of Chicago

    Re: Fiberglass prod draw length

    Post by phuphuphnik on Sun Dec 29, 2013 5:12 pm

    I don't know about the 150s but I just bought 3 of the 80s. I'm measuring 6" with a 17" string. Thae might go further, but I can't pull it back any more. I got them from the crossbow store's ebay page for just shy of $10 each.  I'll gladly let you buy one off of me, as they won't do for my stonebow project. All that said, I'll be getting one of the 150# or the 120# and I'll let you know what that draw is in a week. I'm hoping they are around 11"
    cheers!
    chriso

    EDIT Geezer beat me to it with the 150s. Glad I didn't order one yet. Might need to redesign the stock...
    avatar
    woodsmith
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows

    Posts : 16
    Join date : 2013-11-07
    Age : 62
    Location : Kitchener, ON, Canada

    Re: Fiberglass prod draw length

    Post by woodsmith on Mon Dec 30, 2013 5:11 pm

    Thanks Geezer and Chriso, I'm glad I asked at this stage. The PVC prod I made is drawing 11" on top of a 4" brace. I have some decisions to make before I go any further.

    jeep
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!

    Posts : 379
    Join date : 2011-04-07

    Re: Fiberglass prod draw length

    Post by jeep on Tue Dec 31, 2013 3:31 am

    About the Taiwanese fibreglass bow 150#. (Referring geezer measurements: brass 8,89cm draw20,32cm) I am a regular user of those for various experiences.
    For my first bullet crossbow (Midleton inspiration)
    I used split limb 150# fibreglass
    brass 10cm  draw 22cm
    For the slur-bow (fibreglass)
    brass 10cm  draw19cm
    XIX th cent hunting 2x 150 fibreglass
    brasse 10cm  draw 23,5 cm

    For the bullet crossbow Richard Midleton point out that he don't succeed to use fibreglass limb because of the poor torsion resistance  (bullet need extra angle). This is the reason why I used split limb (centre shot, no angle)and there he work pretty well .
    I most of the time use the fibreglass over draw. I found a lot of tolerance but by precaution I all-way wrap them with  tape string or leaser. When is going to give up it produce crack before.
    my bullet crossbow

    jeep
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!

    Posts : 379
    Join date : 2011-04-07

    Re: Fiberglass prod draw length

    Post by jeep on Tue Dec 31, 2013 3:31 am


    jeep
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!

    Posts : 379
    Join date : 2011-04-07

    Re: Fiberglass prod draw length

    Post by jeep on Tue Dec 31, 2013 3:45 am

    This kind of bullet crossbow with 150# bow is not a toy!!! it is incredibly powerful and potentially dangerous if not well cantered and balanced. This is a weapon....
    Some time the bow brake. Look the  last development  post  XIX th cent crossbow
    avatar
    Gnome
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!

    Posts : 399
    Join date : 2011-10-16
    Age : 53
    Location : Capitol Area Maryland

    Re: Fiberglass prod draw length

    Post by Gnome on Tue Dec 31, 2013 11:42 am

    For the full size 150lb prod, you should be able to draw 10 inches from a 3.5 inch brace height with no problem. I have one build that draws 12 inches from the same brace height. Now that I've explored the limits of the prod I can tell you I probably won't ever do that again. Too scary, even with a very strudy wrapping around it. I draw it with a cocking rope, and even then, the last inch or two I can feel a lot more resistance. So I would say 10 inches is a safe maximum draw for the designed brace height of 3.5".
    I'd also reccomend testing each individual prod- they may look identical, but there are definitely some variances in their construction. I had one crack on me while stringing it on my press, it wasn't flexed more than a few inches.
    Gnome

    Sponsored content

    Re: Fiberglass prod draw length

    Post by Sponsored content


      Current date/time is Fri Jun 23, 2017 9:37 pm