D Bow ?

[bowsandroses]

Sorry I don't spend much time on the computer, so I'm probably asking a question that gets answered a lot I'm building the nephew a bow for christmas and I'm after a D bow never built one before. I am wondering is there an advantage to centering the bow or using possitive tiller. I hope I said that right.
Thanks Hugh.

[JW_Halverson]

It's only one grade above an F bow, or one that failed.  Really, you should try harder, buckle down young man or we will have to take away your X-box privileges.
   


The D means the shape of the bow when strung.  If you were to look at a side view of the bow, when strung, with the string to the left and the arc of the wood to the right, it appears to make the letter "D". 

As a bow like this is drawn, the entire bow bends from tip to tip , to some degree.  Even the handle section.  If you stiffen the handle section, you no longer have a D bow.  They are often referred to as a "bend-thru-the-handle" bow, or a bendy handle. 

If you post a picture of a well made D bow on this site, you will get a lot of positive compliments.  Because of their simplicity, it is difficult to hide poor tillering or bad design....if it even survives!  A good "D" bow is a thing of beauty, efficiency, and a wonder of design. 

[bowsandroses]

Ok I don't know much but I do know a D bow is a bendy handle. Now can I have my x-box back JW please? Any hoo the other bows I have made are stiff handle flat bows with my arrow passing 1" above center and the bottom of my handle 3" below center, which I think is referred to as positive tiller am I mistaken? My question comes from my horrible habit of over thinking it and under working it In the process of over thinking it, it seemed to me that if I built the bow with the lower limb shorter the apex of the bend would be at the top of the bow hand. Thus in my mind putting more bend ( strain) in the bottom of the shooting hand, causing the bow to be uncomfortable and possibly having more hand shock. Now because this bow is not for me I am trying not to allow my above mentioned faults to create a failure for the Lad who will own it

[Weylin]

Hey there. Here is a recent conversation that talks about the pros and cons of positive tiller. You might get some good insight here. http://www.primitivearcher.com/smf/index.php/topic,36316.0.html

[bowsandroses]

Ha Ha hehe! Oh boy I just a little slow I think I see what your saying the bow don't have a handle at least not a big handle like a stiffy wich I truly relised before asking so automaticly your hand would be equaly above and below center when shooting is this correct?

[JW_Halverson]

I've had pretty good luck putting the arrow pass on a D bow dead center.  Yup, you end up gripping the lower limb only, but with a loose grip, you can allow the grip area to bend naturally and avoid all the fuss and bother of trying to apply differential tillering to the limbs. 

Bendy's can be pretty short, basically double the draw length.  But if you add another 10% or a bit more for safety, symetrical limbs are pretty easy going and forgiving to tiller and shoot. 

Post pics and we'll talk about the whole X-box debacle.

[bowsandroses]

Thanks JW and Weylin on both accounts question answered. And yep over thinking again it's still a matter of preferance. JW I will post pics of the first D bow and it's sister stave I finished today for the Niece.

[Shaun]

"Tiller" can mean four or five different things - none of them handle placement.

 "D" bow can mean the shape of a full compass tiller (bend shape of the arc is ONE meaning of tiller) and it can also refer to the cross section of the bow wood with the flat side of the "D" being the back of the bow.  The most frequent usage of "D" bow I've seen is to describe a English longbow with full compass tiller and "D" cross section following the 8/5 rule - that is a ratio of width to thickness minimum. Handle placement on such a bow is open to debate and opinion as in the recent thread on this subject and is applicable in both flatbow and ELB designs.

Handle placement is also not related to positive, even or negative tiller (this is a SECOND meaning = the measurement and difference if any between the upper and lower limb spacing from the string).

Other meanings of tiller include; Verb, the action of shaping the wood to bend in an arc. Noun, the stock of a crossbow. There are others I'm sure. And these are just the meanings that have to do with archery...