What is causing my newly handcrafted bow to vibrate so much?
What can i use to dampen it?
Did i make a mistake along the way?
Is this common?
A few pieces of information may help. What style of bow? Recurve, Hill-style longbow, modern relex-deflex longbow; draw weight, total arrow weight (with point. Do you shoot low wrist, high wrist or somewhere in between?
I am sure there are some here that could help you figure out the problem with some additional information.
First, set the nock point and adjust your brace height to the point of least vibration. The brace height will vary with every bow, even between the same makes and models. That usually takes care of 90% of my vibration issues.
Also, how new is the build? If it is a self bow or flat bow, the limbs may take a while to get "shot in". Once they get a hundred shots or so, they tend to settle down a bit. I'd also recommend playing with brace height, nock point, string material and silencers, and using as heavy an arrow that you can with a tolerable cast.
Just finished the major tiller, rasp the whole way through.
Untested Long bow feels like 50# with a shelf cut half of a 5/16 arrow past center
60" unstrung and a 60" 14 strand B50 string.
Bracing right now at 8", i draw to 26.5"
Split finger.
28" handcrafted untested maple shafts. They feel like a 1535 i think. Burnt tip points for now
(waiting for a delivery (100gn) .)
Havent tried string dampers yet...
The arrow weights 247gn. fletched and untipped.
Brace height is high for a longbow
Arrow is really light unless you have a 200 grain tip on it
B50 in general will have more vibration the a FF type material
Ouch, thats the longest string i have right now...
What length is your bow and string? for a longbow the string is usually 3" shorter than the bow is. For instance if your bow is 64" (like mine) then a 61" string is pretty ideal. However I really don't go by length I solely rely on brace height. Right now my store bought FF endless string is 61" and my brace height is somewhere around 8 1/2" which in my opinion is too much. So I made myself a B50 FS and adjusted (twisted) until I got my brace height set at 7".
Arrows way too light for one. A "FF" type string should help also.
The shafts can't be like a 1535, I shoot 1535's out of all of my bows with no vibration ( LB's and curves ), heaviest being 54#. My arrows are 29"L, 5' feather, 50gr. brass insert, and 125-175 gr. field pt. or broad heads. Your string is the wrong size.
I'll also add, that if I ever tried to make a bow, I'd probably end up with a tooth pick, and that is if I was lucky. So my hat is off to you for doing it no matter how it turns out.
I agree that the brace height is too high, but from the information we have, the arrow weight is at least 1/2 as much as it should be.
If it were me, I would start out with about 450-500 grains total arrow weight as a minimum.
Good luck, and hang in there.
If the bow really is somewhere around 50#, you are shooting something like 5GPP arrows. I would guess it really vibrates! As kat said, that's half the weight arrow the bow should be seeing (at a minimum). I'd get the arrow weight up to 500gr and see if that doesn't help a bunch.
Thanks so much for everyones input... Some great info folks.
Be sure to tell us what you find when you've experimented a bit!
QuoteOriginally posted by PebblePlacement:
Ouch, thats the longest string i have right now...
a lower brace height is not going to help your vibration.
have you mapped your limbs yet, and made sure the limbs are bending the same?.... balancing the working portion of the limb and getting the profile as close to the same as possible will effect vibration the most. the same profile will help balance the mass weight in the outer portion of the limbs.
next would be your string tension at brace being too low. a higher brace can help a bit with that, but not a lot....hope that helps... I'm not much of a self bowyer personally, but you may try flipping the tips a bit to increase the preload.....kirk
I am making 11/32 shaft woodies tommorow. I had jumped the gun on the bow and did this special custom finish i was eager to try on it, but i rasped somemore tonight... I think with the new dynamic to the limbs and the heavier arrows this puppy is gonna go like a rocket!
(if my thin shelf holds) :)
How about a pic or two, braced and full draw.
Do pictures need to be uploaded from a site? Can i just display pictures from my computer?