limb vibrations on R/D longbow

[reini]

Hi guys,
having problems with the latest laminated longbow i built.

I've already built many bows, but this one is the first one showing vibrating limbs.
After shooting an arrow, both limbs are doing strong vibrations for about 3-5 seconds.
It's not a handshock, just these vibrations in both limbs.
Varying the brace height didn't change much.
The tiller i think, is ok too.

Thinking about string material (BCY 8125G), but i'm always using the same and never had this problem on any other bow.

Any ideas out there on how to solve this problem?
Thx Reini

[Crooked Stic]

Are the limbs bending the same all thru the draw.. In other words limb timing. both ends back to brace at the same time.

[reini]

Are the limbs bending the same all thru the draw.. In other words limb timing. both ends back to brace at the same time.

... yes they do, i've checked some positions on the tillerboard.
And there's almost no handshock, so limb timing should be ok.
It's just the strong vibrations on both limbs for a few seconds after the shot.

I can feel and see it vibrating, it's stronger at the end of the limbs, would say the outer halves.
And i think i can exclude the tips, they are really small and lightweight.

Thx Reini

[Mad Max]

What # bow are you shooting and how heavy are the arrows?

[reini]

What # bow are you shooting and how heavy are the arrows?

draw weight is 40#@30"
bow length 67",  R/D glass longbow
Arrows are at 10gpp

[Mad Max]

I did a search and all I can find is to make a new string with something different.

[reini]

I'll build a FF+ today and see if it's getting better.
Thx Reini

[Flem]

Can you post a video of the bow being shot?

[Crooked Stic]

Yep try a low stretch string first.

[Wolftrail]

Had a recurve that sung and shook like a stuck goat,  changed the string from endless loop FF to a Flemish and also installed furries on the strings.  Reduced the noise by 85%.

[reini]

So, put on a FF+ with silencers and it's MUCH better now.
But it's not gone, still annoying.
Just wondering what the reason is, to avoid it in the future ....

Thx Reini

[Crooked Stic]

May take about 100 arrows for the string to settle in good if you did not stretch it first.

[Mad Max]

Move the nock up or down on the string and shoot some

[Mad Max]

Maybe it needs a little tillering on one limb