Tillering strategy?

[mwosborn]

Working on this piece of osage and I could use a little advice.  Have not tillered one like this yet.  Stave was a bit curvy with some reflex and deflex found in it.  How would you tackle the right limb.  Thanks!

First picture is the stave.

Second picture is after roughing out - before straightening.

Third picture is after straightening  (dry heat 2 sessions) and floor tiller.

[Bryce]

Take wood off until they bend evenly(<- relative term.) and be mindful of the natural shape of the stave.

[mwosborn]

Thanks Bryce - it the "relative" term part I am asking about .  The bows I have made so far have had limbs with mostly the same or very similar profile.  As I tillered I could see and feel if the limbs where bending evenly.  Not sure I am going to be able to "see" on this one.  Kinda want to know if the right limb will remain "flat looking" in that reflex area even when the limbs are bending evenly.

[Bryce]

Okay! I see what your asking!
I've painted the wall behind my tillering set up with chalkboards paint now if I find that a stave has some ups and downs and what not I'll simply take some chalk and outline the original shape of the stave to accurately measure the amount of travel for each limb.





I've seen ppl draw a line on the side if the limb, but to me that seems like a good way to induce excess set. Sense the limb needs to first be bent to the problem then held there while measuring the bend with a straight edge. And sometimes that method isn't always an option.



I hope that helps. Now go bend that stick!

[mwosborn]

Thanks!  I like the idea of being able to draw the original profile behind the tree.  Might try to rig something up.  Oh I am going to bend it - for better or worse she is getting bent!

[Weylin]

On staves like that you have to put more faith in the thickness taper and less in how it looks. Use your fingers and feel the taper. You can notice even slight changes and find thick and thin spots. If the taper is spot on the tiller likely will be as well. I also use the method of drawing a straight line along the side of the limb and then holding a straight edge to the line to measure the deflection once it's braced. Like bryce said, this doesn't work with every stave (you can't get a straight line on some limbs!) and you have to be pretty close with the taper/tiller to get it braced without causing set or a hinge. But it has worked for me on many difficult profiles.

[Bryce]

On staves like that you have to put more faith in the thickness taper and less in how it looks. Use your fingers and feel the taper. You can notice even slight changes and find thick and thin spots. If the taper is spot on the tiller likely will be as well.

Bingo! You can pretty much tiller a bow almost completely that way.

[mwosborn]

Thanks guys - that helps!  1:00 am in the morning?  You guys are crazy!

[Carson (CMB)]

Like Bryce and Weylin said. 

Once you have it braced, try to do a lot of work drawing the bow by hand.  Be sure to pull the string with your fingers at a realistic nock point.  Feel for balance between the limbs as you work it back.  If you have a big mirror or bowyer friends handy you can complete tillering in hand. 

[aaron]

1. I agree that you can (almost) tiller a bow by careful measurement of thickness taper- I do this with VM bows to get them at least to brace with good tiller.
2. Bryce- can you tell us more about the bow you pictured? did you heat deflex the handle of an over reflexed stave like carson has done?

[mwosborn]

Thanks aaron!

The bow Bryce posted looks to be laminated - I am guessing the profile was glued in.?

[Bryce]

Yes. It's a boo backed osage.

[mwosborn]

I nice looking profile I might add.   

[Pappy]

You ask for strategy,so mine would be to straighten it out with a heat gun,then tiller. If not the other Ideas are all good ones. Some like to use what they have,I like to make it what I want it to be.
  Pappy

[Slackbunny]

You ask for strategy,so mine would be to straighten it out with a heat gun,then tiller. If not the other Ideas are all good ones. Some like to use what they have,I like to make it what I want it to be.
  Pappy

I tend to agree with this school of thought. Why work around it when you can change it to something better? To each his own though.