I learned a ton today

[Ranger B]

Guys, I've been making selfbows for quite a few years now and I never cease to learn, but today I learned and encyclopedia worth of knowledge.
I'm working on an osage selfbow. It is tillered perfectly at brace. To the millimeter every two inches both limbs were perfect but at full draw the top limb was 1/2" further than the bottom so 1/2" positive tiller. I also tillered this bow for shooting 3 under. If I have developed anything over the past year and a half it is a good bow arm. I absolutely let the bow fly to target when I release the string. Well, I shot the bow and it launched out of my hand. So I put the bow sling on and it ripped my wrist bad. I put the finger sling on and it liked to have pulled my thumb off. I literally have a bruise on my wrist. This bow was killing me. I was really frustrated so I put it on a tiller pulley with a grid so I could see each limb tip perfectly at full draw. The top limb was still 1/2" more than bottom so I tillered it perfectly even. Both limbs even at full draw. Perfect! Smooth as glass.

So, what did I learn? Well, once you release the string the limbs are only concerned with going back to their position at brace so an even tiller is fine. The string may be contorted but the limb tips are going back to brace. If those tips are uneven at full draw you will feel it in the grip. So, if you feel it in the grip how much is being manifested in the string? I'm not sure but I imagine it is.

Lastly, I gripped the bow to keep from dropping it and my arrows moved 6" to the right. I let the bow fly upon release and they returned to the center line. So when you turn your whole bow arm into a dampener you change the spine of the arrow. When you let all the energy of the string enter the arrow it weakens the arrow. So you'd be better letting it fly each time rather than risk gripping the bow just a little different each time, creating left to right issues. I could write a volume on this but I think you get the gist of what I learned today.

[Badger]

    Sounds like what you had is what we often cal an "aha" moment. I am not so sure a 1/2" difference would do this in all cases. I would imagine all my bows are about 1/2" off or so either way and I seldom get any handshock. I do agree with you about the grip, I let the bow align itself as I draw back and just lightly grip it on release. I had a bow a few years ago with shock like you described and I never could figure it out. Maybe the 1/2" would have done it.

[Pappy]

I agree with you Badger I feel sure most of mine are also,I shot the bow Jimmy is talking about,no shock for me,I think sometime it is the style of shooting,I use a light grip. I have had a few over the years that would jar your teeth, I think I cooked brats with them. Jimmy did you narrow and lighten the outer part
of the limbs while you was re tillering ? If so that may have had something to do with it  getting better also.
   Pappy

[Ranger B]

I did thin them down but I think I could take them even further down.  It wasn't a shock so much as a jump forward in the hand.  I can usually hold a bow if I think about it.  This one I just lightly wrapped two fingers around and shot and it rocketed out of my hand.  I do think that every piece of wood is different.  But I tell you what, with that wrist sling on that bow bruised my whole left hand.  It jerked the crap out of me as it launched forward.  I think ultimately this is good because that bow is wanting to straighten itself out bad so when you release it's moving forward.  It has remained straight as an arrow through this shooting.  Hopefully, it will remain that way.

[Pappy]

I have had some scock but never seen one that wanted to jump that hard forward out of my hand,I only light grip them with a couple of fingers and if I shoot them right they just kind of rocks over. Anyway glad you got it worked out,it was a very nice piece of wood. Can't wait to see it all finished up.
   Pappy

[Badger]

Ranger, this does bring up an interesting theory though. The bow and arrow have a fight going on between them. The arrow is trying to stop the bow limbs and the bow limbs are trying to move forward as fast as they can. Light tips on the bow allow for fast acceleration and also remove some of the momentum the limbs have at the end of the stroke allowing the arrow a better chance of slowing the limbs. Idealy the arrow would stop the limbs at the very moment the string hit home, This is one of the reasons low string angle tips at brace are more efficient, the leverage better favors the arrow in this fight.

[Gaur]

Sounds like that bow had come wildness in her and you got her reigned in now.  I'm wanting to get back to work on some bows soon as well.

[artcher1]

Curious Ranger, did you design your bow with 1/2" positive tiller or did your bow develop that much from shooting in? General rule of thumb for shooting three under is even to slightly positive tiller to start with. So why the 1/2"?

Arrow pass above center determines type of grip. Or at least it does for me. And if you lay out your bow for the way you grip it, or grip a bow for the way it was laid out, having equal limb strain at full draw, can only produce a pleasurable shooting bow.

That being said, I'm always learning something new that improves my bows also. Great topic......Art

[mullet]

 Yep, you got me interested, too. Good observation and discussion. Is your string B-50 or Fast Flight? I'm very interested in what gets tossed around in this thread. The bow I got to shoot 209.9 is so noisey that I won't hunt with it. It will not quiet down unless the Brace Height is 5" or less shooting Fast Fight and it jumps in my hand also.

 I'm curiouse with what you come up with.

[George Tsoukalas]

Absolutely! It is full draw that counts brace tiller means very little within reason. That is very important particularly with character staves not so much with boards where brace is a good indication of full draw tiller. Next test for a bow is how she feels when drawing and shooting. Forget about where the arrow goes. Is the handle pressure even when drawing and releasing? That's going to be different for each shooter. The last test is how she looks n the hand when drawing and for that a full length mirror works  but for a modern primitive (how's that for an oxymoron?) the digi pic is a valuable aid. I favor the arrow pass at 1.25ish inches and even tiller or bottom limb a 1/4 in stronger at full draw while in the hand. I used to love watching student's eyes when they had those eureka moments. I'd roll my eyes a bit when I'd say something over and over and the kid would finally get it but say, "Why didn't you tell me?" Ranger, you probably heard what I wrote above over and over but you weren't ready but I am glad you are now. Jawge

[artcher1]

I had a few that were too noise to hunt with also Eddie. None jumped around though. Got 'em nice and quiet now.........Art

[mullet]

 Art, It's not really jumpy or hand shock, just feels different. I'm going to try B-50 and see what it does. Any suggestions? and the tips are even at full draw.

[Ranger B]

It developed it but I'm telling you that bow is shooting great now.  I'll post pics and even a video later.  I'm shooting a D-10 string so you would consider it fast flight.  It's 0 stretch.  BUT, I was shooting a B-50 to break it in.  I figured it out though.  I had to move the tips to align the string and I blocked it where I wanted the limb to bend then heated but I put the pressure at the tips so the bow bent at the weakest spot and not where I wanted it to.  I have since reheated and bent it where I want...lower in the limb...and it did the trick.

[mullet]

 Jimmy, I'll pack mine and see if I can tweek it or figure out what's going on. The bend could be the problem because it is a special glue up that is highly R/D. There is a lot of string touching the wood when it's quiet and barely touching when it is a 6.5-7" brace height.

[Marc St Louis]

One of the reasons I like to tiller by how it feels in my hand