What determines distance from limb tip to riser shelf??

[SEMO_HUNTER]

When making a bow with a cut out riser w/shelf, what determines the length of tip of top limb to riser shelf, and tip of lower limb to riser shelf?
I've seen bows that appear to have different length limbs with the upper or lower always being longer or shorter than the other. Could someone please explain this to me? Is there an equation, or rule of thumb that I haven't ran across yet?

I can't wrap my mind around why both limb tips can't be even distances from the riser shelf I guess? That just seems logical to me.

Thanks,
SEMO

[hova]

i would say it has to do with your hand and dead center... if you have a big long riser , you would probably want the top limb shorter i would think...


then again i dont know much , im just speculating , but i have wondered the same thing...

[SEMO_HUNTER]

Well actually your hand would be below center because the riser shelf is roughly 1/2" to 1" or so above your shooting hand. It all depends on the bowyer making the bow I guess?

It would be nice to have a more precise explanation on the subject, rather than just guess at how long to make each limb and where the riser should be.

I know somebody out there has a wealth of bow building knowledge that can explain this in a way that a budding bowyer can understand it?

[hova]

im sure there will be someone to pop in , it may take a few days , but im sure enough googling can find what youre looking for...


-0hov

[Art B]

Do a search for "arrow pass". Lots of info there. This one is in the search group.  http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=002170#000001

Art B

[Swissbow]

It has to do with the tiller. Depending on your shooting style you want to have more or less positive tiller. This can be achieved by making the upper limb a bit longer therefore it will be weaker that the lower one.

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Andy

[SEMO_HUNTER]

When you all say "A bit longer" about how much would you think for a guy who shoots with 2 fingers under? Are we talking about an inch or so, or more?

Thanks for the fine explanation Art, I was really blown away by it at first, but then went back and read it a second time and it made more sense. I think I've got my mind wrapped around the concept better now.

[hova]

was just on jawge's site , and found part of the answer to what youre looking for

 http://georgeandjoni.home.comcast.net/~georgeandjoni/handlestyles.html

talks about limb length an tiller. just what you need!

[Swissbow]

I can't tell you exactly how much longer the lower limb has to be since I make the limbs always of equal length on my bows. I leave the lower limb a tad wider to achieve the positive tiller.

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Andy

[SEMO_HUNTER]

It may help if I explain what I'm building.

I cut 2 pieces of Osage and squared them up, then I've got a piece of Rosewood I found in some scrap in my garage that's almost the same size as the Osage. I'm going to sandwich the Rosewood in between the Osage for my riser and make a take down longbow or maybe recurve the limb tips a bit and was actually wondering about the limb lengths in relationship to the riser. I had planned on cutting my riser shelf dead center, but then my hand will be below that, so all this positive tiller will come into play because I will be gripping the bow below center. I guess that's what you all mean by leaving the bottom limb heavier/shorter and the top limb longer/weaker to even out the fact that I will be gripping the bow below center.....is that correct?

It's kind of hard for me to grasp because if I grip the bow below center, I'm in effect already shortening the lower half of the bow and making the top longer because it's above my hand.
It's a bit mind boggling for a new bow maker just starting out. I've only got one Osage longbow under my belt so far and it turned out fairly good, but I had no idea on where to put the shelf so I just went 1" above actual center. Maybe I got lucky with that one?

[David Ricke]

Hunter, You are on the right track. I usually make both limbs of equal length with the handle pressure point the center. Shooting the arrow one inch or so higher than center this makes the bottom limb a little longer. this can be adusted by tiller. I don't think the average shooter can tell the difference. Earl Hoyt use to reverse the limbs on his take down bows and could tell no difference. Good Hunting Knifemaker

[SEMO_HUNTER]

Thanks, I've got a real good Bear Grizzly recurve that shoots very nice, I had thought about taking measurements off of that and using it as a referrence for my self bow and riser. Then custom tiller it until it shoots right, looks right, and feels right.