more elb tiller stuff

[willie]

I read the topic "elb tiller" with interest,

,, thats what makes those bows so cool,, there is a bit of room for interpretation on the tiller,,and the bow will tolerate some varience,,

brad has brought up the subject that there is no "one" best, and accordingly, I am interested to hear more from all the experienced folks we have around here. this example is a sketch of a bow with a somewhat stiff handle. I would like opinions, about the design, your thoughtts and what one considers  a reasonable alternative to the circle of compass type tiller.

72" bow at 7" brace and 32" FD

[Badger]

   A couple of years ago Josef asked me to build him some elbs for flight shooting. A 90# and 2 -50# elbs for his wife and son. All 3 broke world records. I used a circular tiller with stiff outer limbs and a slightly stiffer handle area. I did build them all according to projected mass and used the no set tillering method. I had to build 2 of each to get it right on the second try. I was really proud of the 90# as it broke the record by about 50 yards and was about 50# lighter than the current record holder. The bow actually shot 512 yards in practice but I think he over drew it a little bit and crushed some of the speed out of it. I had it tillered for no more than 28".

[willie]

thanks Steve.

I was hoping you might comment. seems like you got those bows for Josef just right. Did you ever get any good profile pics at FD?

or were they much rounder or flatter in the handle, than the sketch above?

[Badger]

  They were made to the 5/8 ratio with a fully rounded belly but moderately rounded. I used a little reflex and one of the keys was pretillering so the reflex was an arc of the circle, that made it invisible once tillered out.

[Badger]

Willie, I think I sent you a message?

[Bayou Ben]

  I used a little reflex and one of the keys was pretillering so the reflex was an arc of the circle, that made it invisible once tillered out.

Can you elaborate a little on this?  So you made sure the reflex was spread evenly to allow for arc of the circle when drawn?  I have thought about this subject, tillering for arch of the circle when you have some reflex. 
   

[bradsmith2010]

STeve did that mean the limb looked a little stiff

[Badger]

  Brad, the unbraced profile was just an arc of the circle with about 3" reflex, so a very gentle arc. That way once it was braced there was no visible evidence of reflex.

[wizardgoat]

In the last few years I’ve made loads of yew longbows. On lighter weight bows I leave the handles moderately stiff, and aim for an elliptical shape. Too circular on bows below 40# you can have handshock issues. I should mention, I’m looking to break records with these bows, just sturdy smooth shooters. On heavier bows, I aim for a circular shape, with a bit of stiffness in the handle.
It’s always tough getting those tips to come around just right on long bows, I’d rather have them a bit stiff than whip tillered. 

[willie]

  Brad, the unbraced profile was just an arc of the circle with about 3" reflex, so a very gentle arc. That way once it was braced there was no visible evidence of reflex.

glued in reflex?

[Badger]

 Yes glued in, I do the same with self bows using dry heat.