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.
:archer2:
what do the tips measure? some pics would help, perhaps at full draw and braced.
thick heavy tips will cause hand shock.
The tips at the nock are about 1" by 3/8" maybe. I forgot about that... I'll try to post pics tomorrow
its probably the tips like rich said, even i usually leave them thicker than they really need to be
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)
Hand shock is generally caused by the limbs being out of time with other or by excessive limb tip weight.
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.
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.
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.
what is a positive and negative tiller?
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.
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,
I think he means they are 1" long and 3/8" wide.
No dutch had it right. 1" wide by 3/8" thick
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?
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
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
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.
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
Thanks nick that actually made a ton of logic. :)
Great explanation of tiller as applied to handshock and tip size Nick. I have a question though, on selfbows do you taper to 3/8 tips from where your limbs taper or do you simply taper them smoothly into the rest of the limb? When i build i generally start with my limbs tapering to 1/2 inch nocks from 15 inches or so varying on limb length, should i just start tapering straight to 3/8 instead?
Richard that is what i did with my last bow, i started tappering to 1" and then on the last foot tappered to 5/8" (? can't remember) But it seems to have worked fine. Came out with a 45# bow.
walkabout, I did something similar to Undercontrol on my self-warbows; tapering them from a foot outside the riser to imaginary 1" wide nocks, then tapering the last foot even more towards 1/2" wide nocks; an increased taper.
this bow was tillered elliptical(increasing bend towards the tips), but the bend didn't increase on the last foot since it had additional taper; since the tips were similar to those on a pyramidal bow. Great bow, untill I chopped it down for a kidbow.
but Usually I like to taper my limbs straight out of the fades to my 3/8" wide nocks, or start the taper like 1 foot out of the fades; depending on the woods density and the staves dimensions. This is what I suggest on a flatbow.
If I had a bow that tapered from say midlimb to 1/2" tips, and I wanted 3/8" tips,,, well, I wouldn't bee too accurate at all. just doing a few strokes with my spokeshave over the sides till I get where I want. Bowmaking, at least for me, is not rocketscience, but does require little logic and physics.
Nick
makes sense, ive been leaving them full width till just after midlimb, then tapering from there in a flatbow design. its worked pretty well for me, i just wasnt sure about the tips. usually i wait till i get the overlays on then work them down thinner to keep mass down.
1 inch wide tips are your problem. Take them down to at least 5/8th wide, but leave the 3/8th thick.