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Main Boards => PowWow => Topic started by: Mohillbilly on May 15, 2007, 12:55:00 PM

Title: longbow profile? with crude pic
Post by: Mohillbilly on May 15, 2007, 12:55:00 PM
I have a question about the design of a R/D longbow limb.  Picture if you would two bows, both R/D, identical in every way except that one bow has more of a straight profile associated with the last 1/3 of the limb.  The other bow has a more curved shape to the last 1/3 of the limb.

What I am trying to get at is one bow has a nice curved arc from the deepest part of the deflex to the limb tip while the other bow has a straighter profile from deepest part of the deflex  to the limb tip.  

How will this affect performance and overall strung profile of the bow?  

Sorry if my meaning isn't overly clear.  All help is appreciated.  

Bret
Title: Re: longbow profile? with crude pic
Post by: elk ninja on May 15, 2007, 01:11:00 PM
Good question, no answer here.... maybe Adcock will pipe in, or one of the other (many!) bow design gurus around.  

I am curious why there is not as much design opinions and debates among recurve shooters....
Title: Re: longbow profile? with crude pic
Post by: Mohillbilly on May 15, 2007, 01:19:00 PM
Pardon the bad drawing but this is what I am getting at.

 (http://img.photobucket.com/albums/v617/Dogvet99/arc.jpg)


Bret

also note that the max. amount of reflex is the same for each bow, theoretically.
Title: Re: longbow profile? with crude pic
Post by: Mohillbilly on May 15, 2007, 03:20:00 PM
ttt
Title: Re: longbow profile? with crude pic
Post by: vermonster13 on May 15, 2007, 03:23:00 PM
Depends on your tapers and such, but all else being equal you'll get more preload on the more pronounced core and should get more speed and possibly more handshock/noise once again depending on limb design.
Title: Re: longbow profile? with crude pic
Post by: Jeff Strubberg on May 15, 2007, 03:30:00 PM
Performance is ;

1.  How far the tips sit forward of the handle (i.e. net reflex)

2.  Moving mass weight.

Assuming both profiles gave you identical net reflex and identical limb weight, their performance would also be identical.

The question is, would the change in design allow you to drop limb mass?
Title: Re: longbow profile? with crude pic
Post by: Dan Bonner on May 15, 2007, 03:33:00 PM
I have puzzled over this quite a bit in building TD and one peice RD LBs. My experience is that the gentler curve will be quieter and smoother to a longer draw length but a tad slower and the tips will roll over into a more Hill style braced profile. The more "hybrid" profile will shorten the working limb some and make the bow more "stacky" at a long draw and maybe a little louder. If you want speed try this design and use a reverse taper or a wedge of core material in the last 1/3 to 1/4 of the limb. You can also boost speed and change the braced profile by increasing the length to the fades a tad but it will jack up draw weight to limb thickness ratios pretty quick.