Author Topic: Hand shock  (Read 4794 times)

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Offline DC

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Hand shock
« on: December 29, 2018, 12:02:21 pm »
I'm just finishing up a Yew ELB and now I know what hand shock is :o I want to decrease it(obviously) without affecting the draw weight too much. I think reducing tip weight is the first step. If I confine my weight reducing to the tip 8-10" will that minimise the draw weight reduction?
What else might it be? The bow looks the same as any other ELB I've made and this is the first one I've had with hand shock. Lucky I guess. The tiller looks as even as I can see. As a matter of fact I was rather pleased with this one.

Offline Badger

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Re: Hand shock
« Reply #1 on: December 29, 2018, 12:11:35 pm »
   I might have a different opinion on this than most but my experience has been that tiller shape is the primary cause of handshock assuming you don't have big bulky outer limbs. I started using a gizmo a few years back and the first thing I noticed was all of a sudden my bows started getting handshock because the tiller was too even and the limb tend to come back all at once. A circular tiller is the worst offender. Using a slight increasing bend as it goes away from the handle means the near handle wood comes back first and the last thing to come back is the tips. It lays the limb out more like a fly line and doesn't produce any shock. I still use the gizmo out to about 23" draw and then I start increasing my tapers in the outer and mid limbs.

Offline DC

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Re: Hand shock
« Reply #2 on: December 29, 2018, 12:54:24 pm »
So I should make it a little more elliptical?
If I try a heavier arrow and it helps does that tell us anything about the root cause? Like if a heavy arrow helps, does that mean the design/tiller is OK but the tips should be lighter?

I tried lighter arrows and it helps. The shocky ones are around 350 ish grains and the heavy ones are 550 ish.

Offline bubby

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Re: Hand shock
« Reply #3 on: December 29, 2018, 01:48:02 pm »
It looks like you already have an elliptical tiller, how is the shock with the heavier arrows? B-50 or FF?
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Offline DC

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Re: Hand shock
« Reply #4 on: December 29, 2018, 02:30:43 pm »
FF and there is less shock with the heavier arrows. I reduced the tips and took a few scrapes off the outer half of both limbs. It feels better but I might just be getting used to it. I'll shoot another bow for a while and then come back to it.

Offline Marc St Louis

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Re: Hand shock
« Reply #5 on: December 29, 2018, 04:27:50 pm »
Yes I agree with Steve.  Tiller shape does play an important role in hand-shock.  Keeping the center section relatively stiff especially in a low weight ELB will reduce hand-shock
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Offline Bayou Ben

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Re: Hand shock
« Reply #6 on: December 29, 2018, 04:48:06 pm »
I’m wondering if the tips are bending too much for this bow. I normally like my tips to break away from the ellipse sooner than that, around 6” or so from the end.

Offline DC

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Re: Hand shock
« Reply #7 on: December 29, 2018, 05:18:37 pm »
Something I did notice building this one is that it's not physically balanced. One limb is heavier than the other. It's odd because it's made from sister billets. One limb was much stiffer than the other so to get it to bend I had to reduce it more than the other. I checked the thickness and width every 6" and made them the same. The stiff limb is around 1/32" thinner most of the length.
While I was measuring the thickness I noticed that one limb, the heavy weak one, is deflexed a bit. I'm going to try to heat treat and pull it straight. That should make it stiffer and allow me to reduce the physical weight. maybe make it balance.

Offline George Tsoukalas

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Re: Hand shock
« Reply #8 on: December 29, 2018, 06:32:50 pm »
DC, you mentioned that one limb was "deflexed a bit". That limb is not doing its share of the work which means it needs to bend more than the other.

The picture perfect, eye candy tiller is not always the best for the bow.

I'm not in the tiller shape affects hand shock camp.

Jawge
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If you ain't breakin' you ain't makin!

Offline DC

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Re: Hand shock
« Reply #9 on: December 29, 2018, 08:06:16 pm »
You're right George and I knew that. Just somewhere in there I lost track of what I was doing. I'm not sure now if the deflex was there earlier on in the tillering. It may be set. I did a little heat treating earlier on and maybe I did one limb more than the other. Whatever, I screwed up and now I get to see if I can fix it. It's all fun and learning ;)

Offline George Tsoukalas

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Re: Hand shock
« Reply #10 on: December 29, 2018, 08:23:12 pm »
You could also turn it around and see if it is less shocky. Jawge
Set Happens!
If you ain't breakin' you ain't makin!

Offline Del the cat

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Re: Hand shock
« Reply #11 on: December 30, 2018, 02:48:50 am »
I think hand shock is one of those grey areas, what one perceives as hand shock, another may think is fine.
I suspect that one cause is simply poor grip comfort.
ELBs (especially laminates) of tend have rather flat backs with a noticeable corner where sides meet the back, that can really bang into the knuckles.
Similarly if the belly is too flat and the grip poorly shaped it can bruise the lower thumb joint.
I've noticed this on some fairly wide warbows and a bit of fiddling and fettling round the grip sorts it. I have an 80# hickory backed Yew and I added a leather pad on the back, blended in to give a rounder grip which made a huge difference. (It looks odd without a leather grip covering the whole grip area... but I can't be bothered!  ::) as I rarely shoot it... it's my only 32" draw bow, so it's just for demo' )
Personally I don't believe arc of a circle tiller is to blame as such, maybe it's more like excessive bend in the centre.
Some longbow "designs" are roughed out even thickness and with over the centre section (maybe 20"), which to me is wrong. My thickness taper starts pretty much from the centre (or a couple of inches either side), and I do fade up a whisker to the grip, so you automatically get a slight thicker grip.

I think there are other contributory factors like brace height too low (or too high?  :o ::) ) Arrow not well matched to the bow etc.
Maybe it's a lot of little details like much of bow making. Once a bow is shootable there is still plenty of tuning to be done.
Maybe just lightening the tips won't help, but if a few other things are done as well, hopefully the problem will get resolved.
Del
« Last Edit: December 30, 2018, 02:58:31 am by Del the cat »
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Offline PEARL DRUMS

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Re: Hand shock
« Reply #12 on: December 30, 2018, 05:17:26 am »
You have been in full RD mode for a while. they are the smoothest by far. The two designs are on opposite ends of the spectrum.
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Offline BowEd

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Re: Hand shock
« Reply #13 on: December 30, 2018, 06:24:23 am »
That's a very good point to remember there Chris.
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Ed

Offline PatM

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Re: Hand shock
« Reply #14 on: December 30, 2018, 06:24:41 am »
You have been in full RD mode for a while. they are the smoothest by far. The two designs are on opposite ends of the spectrum.

 It's probably mostly this.

 Put a nice Gilman Keasey style cork handle on it  and use the arrows that soak up most of the energy and call it good.