Author Topic: optical illusions when tillering  (Read 2784 times)

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Offline tronman

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optical illusions when tillering
« on: October 23, 2009, 12:10:16 pm »
Hello,

 I am working on my 4th bow and had a question. Do any of you experience optical illusions when tillering? I am finishing up this particular bow and my wife says the tiller looks even, but when I see it, it does not. And to make it worse it think one limb might look slightly stiff and then when I flip around to get a different perspective the limb I thought was good looks slightly stiff. The brace looks even. It shoots real good. I ready to believe my wife quit being a perfectionist. If I had a digital camera I would post a pic, but I don't and am  just curious if anyone else's eyes go goofy after looking at bow's tiller to much?

By the way it is a Hickory bow and it is kind of a ALB design.  I m surprised at the amount of set it took. After shooting set is about 2 inches. After rest One limb is about 1/2 inch and the other an inch. I heard that hickory was notorious for taking a lot of set?

Offline Dano

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Re: optical illusions when tillering
« Reply #1 on: October 23, 2009, 12:39:41 pm »
A digital camera really comes in handy, when your eyes are playing tricks. If it shoots good, little hand shock it might be good. Ya gotta trust your wife ;D
I like to use a walkie talkie or Eric's tiller gizmo, takes a lot of the guess work out.
Hickory, when the moisture content is up will take a lot of set, try and keep it dry till it's sealed.
"If the women don't find you handsome, they should at least find you handy."


Nevada

Offline Pat B

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Re: optical illusions when tillering
« Reply #2 on: October 23, 2009, 01:06:18 pm »
Sounds like you may have a uneven limb thickness causing twist in your limbs as you draw. That is not uncommon. With your thumb and forefinger feel the thickness along the limb but also from side to side. I'd bet the limbs are a tad thicker on one side and that is causing the twist.
  If your vice is on a work bench it is common to remove more wood from the outside of the limb while not taking as much from the work table side. This will show up as twist as the bow is drawn.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

coyote pup

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Re: optical illusions when tillering
« Reply #3 on: October 23, 2009, 02:25:19 pm »
I'm with Pat. If you have twist, and look at it from one side, it maye look like the top limb is just fine or not bending enough, and then if you (or your wife) look at it from the other side, it might appear to be bending way too much. Twist is good for doing this to you.

I also think if you had a tillering tree you may be able to decide on the tiller a little easier.

Offline tronman

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Re: optical illusions when tillering
« Reply #4 on: October 23, 2009, 02:56:59 pm »
Yea I did some measuring and their were some minor variances and have been working on them and the tiller seems to be coming around. I only have a tillering stick, but my brother is going to give a tillering tree and I believe this help in bow making. This is great hobby. It keeps me away from the T.V., it's fun, and you get to use your hands and mind to create something.

Thanks for your help
Eric

Offline Pat B

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Re: optical illusions when tillering
« Reply #5 on: October 23, 2009, 02:58:09 pm »
We'll need pics as soon as possible, Eric! ;)
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline George Tsoukalas

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Re: optical illusions when tillering
« Reply #6 on: October 23, 2009, 04:04:08 pm »
That happens to me too even when I flip the limbs one side sometimes appears stiffer and it is not the same limb.   Pat is correct sometimes uneven limb thickness will cause it. Sometimes not. LOL. I always check tiller in front of a mirror. A window at night acts as a mirror too. Then there is electronic tillering using a digi cam. You gotta love it.
Set Happens!
If you ain't breakin' you ain't makin!

Offline Justin Snyder

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Re: optical illusions when tillering
« Reply #7 on: October 23, 2009, 04:24:08 pm »
I like to keep a solid background with grid lines drawn on it. You can tell if they are bending the same and where. You can still flip it for an alternative perspective if need be.
Everything happens for a reason, sometimes the reason is you made a bad decision.


SW Utah

Offline sailordad

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Re: optical illusions when tillering
« Reply #8 on: October 23, 2009, 06:32:32 pm »
was this from a stave or a board?
i have had staves look odd from one side and good from the other(at draw of course)
this always seems to happen when the stave had natural prop twist to it
i always wanted a harley,untill it became the "thing to ride"
i ride because i love to,not to be part of the crowd

Offline tronman

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Re: optical illusions when tillering
« Reply #9 on: October 23, 2009, 08:30:00 pm »
It was a hickory board. This board seemed straight with no twist when I looked at it before I started this current project.

Offline sailordad

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Re: optical illusions when tillering
« Reply #10 on: October 23, 2009, 08:37:20 pm »
i did have board do that once too
one limb had about one half the width and length being heart wood while the rest of the board was all sapwood
but it did,under closr inspection,have a little thickness variance from side to side
i always wanted a harley,untill it became the "thing to ride"
i ride because i love to,not to be part of the crowd