Newbie Bowyer needs help tillering an Osage Selfbow

[Gray Ronbow]

Hi Guys

I am a newbie when it comes to self bows. I have made a handful of bamboo backed Hickory, Osage, and Ipe. I purchased a 72" bow blank and need help to make sure that I am getting the right tiller. I am 6'4" and have a 29" draw. I need to tiller this for three finger under shooting. The right side is stiffer so I am making it the bottom. Right now I have 1/4" positive tiller. This blank had a little bit of reflex in it. Should it be bending more closer to the fades? I have a tillering gizmo so should I use that to create a more circular tiller for this type of bow? My goal is to have a 50lb bow at 29" draw. Please help and make any suggestions.
Thanks
GR

[wizardgoat]

Please post a pic of the bow unbraced, braced, and a front profile as well.
it's tough to give good advice other wise. Looks like a stiff spot and very thick wood right side mid limb. Get the bow braced, it changes the stresses on the limbs, if you go much further without doing so you may come in way under weight

[Pat B]

Low brace the bow first. Everything looks pretty good so far. The outer limbs could bend a little more but leave the last 6" stiff. What is the thin spot about 8" or so from the right fade?

[mikekeswick]

First thing I would do is cut it down to 68 inch That is plenty of length for a 29 inch draw.
What width is your bow out of the fades? What width profile do you have? How you have tapered the width determines what side view tiller profile you should have.
If you have a straight line taper from fades to tips (pyramid bow) then yes it should be circular with a shade less bend right off the fades.
If you have a parallel section of width then a taper into the tips. Your tiller should be slightly elliptical. How elliptical depends on how long the parallel section is. Longer parallel section = more elliptical.
The reason for the above is that any wood at a given thickness can bend x amount, make it thinner it can bend further, make it thicker it can bend less.
Mark where the reflex is if it is just in one spot as that should still be visible at full draw as a slightly straighter section, don't tiller reflexed sections to look like the rest of the limb eg. not like the perfect bend you can get with a lam bow.

[Gray Ronbow]

Thanks guys for your responses. I will get measurements and more pics when I can get back in the shop, and hopefully be able to post by tomorrow.

[JW_Halverson]

Where are you located?  You might have one of round the corner from you, too!

[Gray Ronbow]

Thanks to everyone for your comments here is a pic of the bow unbraced.
OK I have some more information:
- the handle is 4" and 1 1/2" thick
- the fades are 1 3/4"
- the limb width is 1 1/2" wide from fade, going parallel for 17" till it starts tapering
- The limb starts tapering 15" from the end and tapers 1 1/2" to 1/2" at the tips
 
Mikekeswick...thanks for your comments. You mentioned that I should cut it down to 68". Since this is an unbacked self bow, will it be able to take that much tension and compression? The back was worked down to a single growth ring so there are no violations there. The longitudinal grain seems to be running fairly straight as best I can tell there are no runoffs that are obvious and would make it prone to break or splinter.  Hopefully you can see in the pic that the reflex is a gradual reflex from the fade to the tip.

I will low brace the bow and work from this for the remainder of the tiller.
Other suggestions?

BTW I live just north of Austin TX in Georgetown

[mullet]

I can't figure out why the wood looks thinner on the right limb with the door brace behind it? Is there something we are not seeing?

[DC]

I've been looking at that too. It made the braced pic look a little weird.

[ajooter]

Any twist in that right limb?   Looking good so far.

[Gray Ronbow]

I have sighted down the limbs and I don't see any twist. There is a dip on the right limb, and I think that's what you are referring to. Actually the ring that was followed has dip so one side follows that dip because of the ring pattern. The other side is the same thickness all the way down because the rings seem to be straighter going down the limb. Is there something I should do to correct that?
Thanks

[SLIMBOB]

Welcome fellow Texican!  I'm just down the road a piece in Boerne. Good advice thus far.

[DC]

I've been looking at that too. It made the braced pic look a little weird.

"A lttle dip on the right limb" would be what I'm seeing. It doesn't appear to be hinging there so I would say you're good to go!

[Gray Ronbow]

Thanks to everyone for your comments and suggestions. I will post more pics when I get further along.