Author Topic: How does this tiller look?  (Read 1300 times)

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Offline Dances with squirrels

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Re: How does this tiller look?
« Reply #15 on: October 13, 2017, 05:15:13 am »
Here's the same picture with the handle/shelf area straight up and down. I have to imagine that, with the bow held equally straight up and down at brace, before the draw had begun, the arrow would have been level with the ground or slightly elevated at the nock end.

The nock end of the arrow came down during the draw because the bottom limb didn't flex as much as the top.

Offline Dances with squirrels

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Re: How does this tiller look?
« Reply #16 on: October 13, 2017, 05:31:24 am »
And here's how the picture would have looked had he kept the arrow level with the ground during the draw. Notice the relationship of the arrow to the shelf/handle area and how the bow is tilted. The stronger lower limb isn't flexing enough and is pulling the bow into the heel of the hand, while drawing the nock of the arrow down... as it's being drawn back.

We CAN make a bow that's balanced while more heel pressure is applied, if that's how we wish to hold it, but it would/should still reveal balance at full draw... i.e. arrow straight back from the shelf/handle, bow not tipping in the hand one way or the other.

Offline Dances with squirrels

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Re: How does this tiller look?
« Reply #17 on: October 13, 2017, 06:07:50 am »
And this is approximately how it would look on my tillering tree.... but not for long  ;)

Offline stuckinthemud

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Re: How does this tiller look?
« Reply #18 on: October 13, 2017, 06:18:33 am »
Nice set of pictures; I am happy to stand corrected, if that were my bow I know I would be trying to bring that bottom limb around a touch more, but probably only after I posted a 'help me please' photo to PA! ;)

Offline Bryce (Pinecone)

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Re: How does this tiller look?
« Reply #19 on: October 13, 2017, 06:44:16 am »
Has a nice positive tiller. Looks nice to me
Deer Island, Oregon

Offline George Tsoukalas

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Re: How does this tiller look?
« Reply #20 on: October 13, 2017, 08:40:56 am »
Good point, DWS, but I like the bottom limb slightly stiffer. Jawge
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Offline willie

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Re: How does this tiller look?
« Reply #21 on: October 13, 2017, 09:07:13 am »
Interesting responses, I had hoped that more would have been willing to suggest the back shape that corresponds to the bends on this bow, as "what does the back look like" is often asked when a bow is presented for tiller evaluation. I have to admit that the curves look pleasingly smooth, even if they are two different "unbalanced" curves. All three aspects are important, even when prioritized differently by different bowyers.

mikekeswick

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Re: How does this tiller look?
« Reply #22 on: October 13, 2017, 09:50:49 am »
More or less even bend along the limbs shows that for even strain the thickness must be the same/very little taper. A pyramid bow.
The slightly stronger lower limb thing is simply because we don't shoot through the center of our hands :) There is no way to have exactly even strength limbs and a human shoot the bow (and it stay 'in tiller'). We have pressure point/s on the handle and the arrow goes above this/these hence asking the lower limb to do a bit more.
I've messed about with dynamic balance and adjusted my tiller tree to show if the limbs are balanced on the way to full draw by being able to see if the string deviates from a 'straight back' path and it is worth doing....but the problem with it is trying to replicate the way the grip is held/supported by the hand.
Anybody interested in this method can search 'limb timing' thread by 'bowjunkie' over on tradgang.




Offline bradsmith2010

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Re: How does this tiller look?
« Reply #23 on: October 13, 2017, 11:29:37 am »
if the bow shoots well, the appearance in any way is secondary,, (SH)

Offline Marc St Louis

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Re: How does this tiller look?
« Reply #24 on: October 13, 2017, 12:14:15 pm »
The top limb bends quite nicely.  The lower limb bends too much in the outer limb and not enough in the inner limb= lack of symmetry.  The bow would probably have some hand-shock
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Offline Dances with squirrels

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Re: How does this tiller look?
« Reply #25 on: October 13, 2017, 02:49:08 pm »
Mike, Bowjunkie is me  :)

Offline bradsmith2010

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Re: How does this tiller look?
« Reply #26 on: October 13, 2017, 02:50:19 pm »
could it be possible the bottom limb had a bit of reflex,, giving it the appearance of not bending enough,,,

Offline Dances with squirrels

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Re: How does this tiller look?
« Reply #27 on: October 13, 2017, 03:11:39 pm »
Brad, very good inquisitive question. But no. If, for instance, the bottom limb has 3" of reflex and the top is even with the handle, when dynamic balance is achieved at full draw, the top limb will likely be drawn farther behind the handle than the bottom, but the arrow will come straight back relative to the shelf/handle, without causing the bow to tip in the hand.

Folks often ask... "One tip is ahead of the other... should I level the tips or the handle in the tree?" Definitely level the handle. That's how you intend to hold it, right?

Offline Dances with squirrels

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Re: How does this tiller look?
« Reply #28 on: October 13, 2017, 04:39:01 pm »
By the way, Mike, the cradle doesn't have to precisely replicate the bow hand's hold. We can get close enough by most standards if the cradle spans the width of the grip or otherwise holds it in place, and then we adjust the limbs so the string hand fulcrum comes straight down. But we can locate or move, by adjusting limb strength, the exact dynamic pivot point at full draw by putting the bow on the tillering tree, placing something under the handle at the supposed point of dynamic balance to allow the bow to tip one way or the other, then draw it from our string hand's fulcrum point. This reveals us. We can still adjust it so the bottom limb is a little strong if we like, but I bet the vast majority of folks will be surprised at what they find .

Offline DC

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Re: How does this tiller look?
« Reply #29 on: October 14, 2017, 08:15:13 am »
DWS are your bows free to rock in the cradle or are they fixed in some way?
Vancouver Island