Author Topic: Hand shock / twang questions - experienced advice needed...Please  (Read 5441 times)

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Offline Capt

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A couple of questions -

I recently finished my 2nd bow (an 63 ntn 60#@28" Osage recurved tips) as some probably know from recent posts..... when fist finished before adding a rattlesnake skin backing is was shooting super sweet... i mean silent as i remember...
i was shooting coconuts at 20+ yards and the release was almost silent with no hand shock as far as i noticed, and the impact on the coconuts was real quiet as they still had their fibrous husks.... so no sounds or shock......

Before backing with the skins i heat treated while the bow was clamped flat for two reasons really, 1. i wanted to remove a tiny bit of set that the bow seemed to take after shooting it in and 2. because i thought it could up the poundage slightly.. i did the heating prior to backing as i knew i couldn't afterwards without compromising the bond of the backing adhesive....

Well after the heating and backing i left it to sit unstrung for 48 to 72 hours then braced it for some pics... another 24 hours before i shot another arrow....

When i got to shooting i noticed the string seemed to twang on me... not really hand shock so much more like a noise i never recall hearing? maybe a little vibration in the hand..... but more than anything the twang of the string seemed weird..... (the knocking point on the string also seemed to be 1/8" lower???)

i checked the weight and tiller again and the tiller seems fine but it seems to have gained at least 5# of draw weight (i assume this is the backing, heat treating or combination both?)

So my questions are:-
1) Do people think the twanging will go away as i shoot the bow back in?
2)What is Normal in these circumstances?
3)What can i do about it if the twang persists?

i thought to lighten the tips somewhat... as you can see in the pic i left the recurved section of the tips kinda beefy... would removing some meat from the tips help?

i also thought of adding Lynx (bobcat) or badger skin string silencers?

I'd really appreciate peoples thoughts and advice...

Bests to all,

Capt ;)

Offline Holten101

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Re: Hand shock / twang questions - experienced advice needed...Please
« Reply #1 on: October 02, 2013, 03:06:56 am »
It could be several things. My best quesses are:
1- Did your bowyers knot slip slightly? (check brace hight). To solve this try and experiment by twisting the string to increase brace hight slightly until you hit that "sweet spot".

2- Tiller changed slightly, as a result of heat treating and your attempt to correct set, affecting the timing of your limbs. Check the tiller and correct by removing wood.

Just my two cents

Offline Bryce

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Re: Hand shock / twang questions - experienced advice needed...Please
« Reply #2 on: October 02, 2013, 04:33:41 am »
+1 on checking brace height
Clatskanie, Oregon

Offline Pappy

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Re: Hand shock / twang questions - experienced advice needed...Please
« Reply #3 on: October 02, 2013, 05:46:57 am »
I would also guess the brace is to low, and reset you knocking point, string is probably laying on the curves on the re curved tip's a bit more since you added more reflex. :)
 Pappy
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Offline artcher1

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Re: Hand shock / twang questions - experienced advice needed...Please
« Reply #4 on: October 02, 2013, 08:15:45 am »
Capt, when you added weight from the heat treating, which had to be near handle to mid-limb, you added extra stress/bend to the outer limbs. I went back and looked at your finished bow thread and you can see too much upper limb bend from mid-limb to tip. This will cause limb deformation/bounce/vibration. Would cause the string nock to move down also...........Art

mikekeswick

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Re: Hand shock / twang questions - experienced advice needed...Please
« Reply #5 on: October 02, 2013, 10:14:44 am »
To help we could do with a new full draw picture and a picture of how the limb width tapers.
I 've just had a look at the full draw picture you added before and it appears that it is bending a little too much about 2/3rds of the way along the upper limb and a shade flat leading into that section.
Vibration is almost always something to do with limb timing.
I agree with what the others have said about checking brace height and re-adjusting nocking point, it should ,give or take , be an 1/8th inch above horizontal with the arrowpass.
String silencers should be seen as a last resort in my opion  ;) once the tiller and limb timing is perfect the bow will be silent (or near enough) anyway. Get it to this stage and then add them if you want.
Your limb thickness around the recurves doesn't seem excessive and is very unlikely to be the casue of the issues you are having.
When i've heat treated osage i've never really had an increase in weight, my suspision is that the increase in weight is due to it drying fully after the heat treatment. Remember it checking before.

Offline adb

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Re: Hand shock / twang questions - experienced advice needed...Please
« Reply #6 on: October 02, 2013, 10:53:29 am »
Definitely your brace height is low. Unless you're using a FF string, it's probably stretched a bit and your BH has dropped. I always check my BH every time before I shoot any of my bows. Only takes a sec and then I know. For recurves (and the majority of my bows for that matter), I keep my BH at 7". That's measured from the back of the bow. If your BH is too low, the bow is very noisy, and it really whacks the inside of your arm.

Offline PEARL DRUMS

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Re: Hand shock / twang questions - experienced advice needed...Please
« Reply #7 on: October 02, 2013, 11:50:21 am »
I also suggest examining your grip. If your bow isn't sitting in your hand just right it will want to fight you above or below the grip causing a loud, shocky shot every time. Self bows are difficult to shoot compared to any other bow out there.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline Capt

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Re: Hand shock / twang questions - experienced advice needed...Please
« Reply #8 on: October 02, 2013, 11:59:56 am »
Thanks Guys,, heres some more info for you all... again the bow is 63"NTN and at my full draw hunting style its 55#@26"

the Brace hight ive been using is the tip of my thumb from the base of my fist...or 6"

I made a video of me shooting 12 arrows with a more perpendicular style stance and took stills from the video.... Here are the results...

BTW it already feels much better today but here are the FD pics anyway...

Bests and thanks again... ;)

Offline PEARL DRUMS

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Re: Hand shock / twang questions - experienced advice needed...Please
« Reply #9 on: October 02, 2013, 12:13:24 pm »
See that big flat spot on the top limb? That in essence creates a bunch of dead limb above it. That may be your problem.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline artcher1

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Re: Hand shock / twang questions - experienced advice needed...Please
« Reply #10 on: October 02, 2013, 12:56:54 pm »
Here's a better view. Tiller is off, plain and simple. Looks like a hinge starting in the upper limb from mid-limb to tip...........Art

http://www.primitivearcher.com/smf/index.php?action=dlattach;topic=42550.0;attach=91912;image


Offline Capt

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Re: Hand shock / twang questions - experienced advice needed...Please
« Reply #11 on: October 02, 2013, 02:08:02 pm »
Pearl Drums and Artcher1,

Big thanks,,,, i identified a slight stiff spot in the upper limb as you both rightly spotted... i'm sure it wasnt there before the skin job but hey?

i noticed also at that spot on the limb one of the sides was less rounded by quite a degree than the other, i'm pretty sure this happened when i was filing off the excess skin and glue with my metal file.....

Anyway i rounded the edges in that spot symmetrically and thinned roughly one thin growth ring from arround 6" of limb in that area with 120 grit sand paper... the tiller looks spot on once again......

I re braced a little higher at 6 5/8" and shot a few arrows at my 26" draw............. whalah!! it's silent and no hand shock what so ever.. ;D :D :laugh:

i checked draw weight and its still over 50#@26" i'm sure still close to 60#@28" although i never drew it that far to check....

Big thanks.... Happy camper here once again...... ;)

You guys are the best.....

Heres a pic of the area we identified that i re-worked.... I'll post another full draw later when i get chance... got to get off to work going finishing... i have tails to chase / Marlin to catch..

Offline PEARL DRUMS

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Re: Hand shock / twang questions - experienced advice needed...Please
« Reply #12 on: October 02, 2013, 02:20:30 pm »
Right on.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

blackhawk

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Re: Hand shock / twang questions - experienced advice needed...Please
« Reply #13 on: October 02, 2013, 02:43:50 pm »
I have a sneaking suspicion due to your personality you'll be building quite a few more bows in search of that "perfect" bow.....keep on building and you'll find it eventually.... I haven't found mine yet tho  :laugh:

Offline adb

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Re: Hand shock / twang questions - experienced advice needed...Please
« Reply #14 on: October 02, 2013, 03:07:44 pm »
It's the Zen of bow making. It's like surfing the perfect wave, or hitting the perfect shot in golf... it's what keeps us going, and keeps us striving to improve.

I think you'll do well at this. You have a good eye, and you're willing to listen to valuable advice. Journey well!