Hand Shock!

[UnderControl16]

So i just finished a new 53# @ 29", board longbow, 70" ntn, with a handle, only issue is that there is a significant amount of vibration left in the bow after shooting, is there any way i can eliminate this? I'm shooting 3/8" diameter 30" poplar arrows if that matters at all. The vibrations don't affect me really but i have heard that they are very bad for bows.
   

[Rich Evans]

what do the tips measure? some pics would help, perhaps at full draw and braced.

thick heavy tips will cause hand shock.

[UnderControl16]

The tips at the nock are about 1" by 3/8" maybe. I forgot about that... I'll try to post pics tomorrow

[walkabout]

its probably the tips like rich said, even i usually leave them thicker than they really need to be

[Innocente]

i finished my first laminated fiberglass longbow, and while it is WONDERFUL the handshock is like getting punched in the hand by mike tyson, every shot.  i feel your pain. (in my left hand)

[Pat B]

Hand shock is generally caused by the limbs being out of time with other or by excessive limb tip weight.

[Osagetree]

Play with the brace height and be sure each limb is equal in tiller and strength. Correct string nock angles and string materials. And limb twist and thin tips,,, just some thoughts.

[4est trekker]

Diddo to Pat B, but I would add that light arrows will also cause increased hand shock.  If you're not shooting in the 8-10 grains per pound range you may be getting added shock.  The arrow can only absorb so much energy.  Any left over energy not absorved must be absorbed by the bow limbs, string, you, etc.  If they're light, try adding some brass tubing footings to the very tips.  You can get it at Ace/TrueValue Hardware stores and the like.  Depending on the diameter and the gauge, 1" generally will generally weight around 80-100 grains.

[Innocente]

i didn't know that one either 4est.  usin superlight poplar and oak homemade dowel arrows with light target tips.  

although in my case, i got a badly matched tiller on a fiberglass build.  i deluded myself into "extreme positive tiller!" thinking for a bit, but it's probably time to correct it.

[UnderControl16]

what is a positive and negative tiller?

[walkabout]

positive tiller is when one limb pulls more, making the string on that side farther away from the riser. negative tiller is just the opposite of this. generally we want the top limb to have some positive tiller because we stress the bottom limb more due to our bow hand being placed along the top 4 inches or so of the bottom limb, thereby making its working area shorter.

[dutchwarbow]

we can talk endless talk about the timing of limbs, but in that case we wouldn't pay attention to his tips. 1" by 3/8" is WAY too wide. It would be like talking about adjusting a motor without cilinders.

undercontrol, rip your tips down to 1/2" wide or less and see if it keeps kicking.

after that, you can take a second thought about timing of limbs and such.

I've never handled a wooden bow with 1" wide nocks that didn't have handshock.

Nick

also,

[Jason Scott]

I think he means they are 1" long and 3/8" wide.

[UnderControl16]

No dutch had it right. 1" wide by 3/8" thick

[UnderControl16]

I have been looking at different pictures of bows on here and i have noticed that the limps don't evenly fade to the ends but seem to turn towards the ned to get the tips thinner. How do you do yours?

[Jason Scott]

Wow, that is wide and Dutch is probably right.

On glass longbows, the ones I have made and most that I have seen have straight edges from fade to tip. Recurves have a different edge profile usually. A lot of builders find center and measure somewhere around 1/4" to say 9/32" on each side at the tip and put a mark there. Then they mark a spot on the edge of the limb at a point somewhere around 2" past the fades and trace a straight line from that mark to the mark on that side at the tips.

On the only board bow I have ever made I followed these instructions at the link bellow. Take a look at his whole website.     http://www.oocities.com/salampsio/oak2.htm

[Jake Rhea]

I have the same problem with my first self bow and I am mad because it hurts so bad to shoot it. I was wondering how to fix that pleas.

Jake

[UnderControl16]

it seems to be that narrowing the tips is the easiest and the fastest way to help deal with it. just read through this thread there are some great ideas here.

[dutchwarbow]

handshock and tiller go hand in hand. but for imagining a proper tiller for your bow, you have to look at it's front profile and the LEVERAGE!!.

I'll give a try to explain how I mean leverage;

Imagine a bow that bends evenly throughout it's whole length. Since the lever gets bigger and bigger the closer you get to the handle, the more wood you need there. and on the tips would be very, very little wood required right?

a good example for this would be a pyramid bow, with 3" wide limbs at the fades to 1/4"wide nocks. A good tiller would be a circular one

now, imagine you have a bow with an almost PARALEL front profile. Since the leverage is the biggest close to the handle, that will be the most stressed part, if it has an circular tiller. A slowly increasing bend would be ideal; less bend close to the handle,were the leverage is big, more bend close to the tips were the leverage is small. this would evenly distribute the strain. Such an increasing bend is called an elliptic tiller.

so, the more  pyramidal  your frontprofile is, the more  circular  your tiller should be.

the more  parralel  your frontprofile is, the more elliptical the tiller should be.

what has this to do with handshock?

well, if this would be applied correctly, your 1" wide tips would have to move ALOT to do their share    and that would be impractical; the direction of the limbmovement would be affected and create stack. but that's another story.

if you narrow your tips, your tiller would suit your bow better, and less wood would travel the same distance. less energy would be lost, less energy would be put into crunching your hand.

Nick

[UnderControl16]

Thanks nick that actually made a ton of logic.