Bamboo Locust Reflex

[yourpaldan]

Hey folks,
Long time stalker of the site, first time posting.
This is my 3rd bow I'm making now.  I would love any help, if anyone has suggestions.  I feel like i know the basics, but its hard to make a good bow.  I draw a bow 30", so it will need to be able to handle that, and I'd like to use this bow to hunt deer in the fall.

 I had a black locust board 35" long, and i was able to get 4 billets out of it.  The first 2 are currently in a bow with sinew drying... Ill post those pics later.  But the other 2 i made a bamboo and walnut tri lam out of.
I cut billets 1.5" wide by .75" thick, connected with a Z splice.  Came out sloppy so i had to add shims in the splice during glue up.
the bow ended up being 66" long.

I steamed in some reflex... 30 degrees bend for the last 5".  Then i heat treated the belly while it was pulled into a backwards brace. 
I probably should have just made it straight so i could tiller easier, but i figured the reflex will give me a longer draw.

[yourpaldan]

I cut the bamboo to size, and tapered it so the ends were razor thin, and it had about 0.15" in the center.
The core is walnut tapers, from 0.12" down to 0".  I also made a walnut riser/power lam? thing to give more body to the splice.  It's just a thin curve of walnut, 8" long.

The bamboo didn't bend easily at the recurves, so i had to pre steam it. 
I glued everything using Unibond 800, so i scratched up the surfaces a little bit first. 
Then i set the rig in a little bathroom with a space heater over night to cure.

[yourpaldan]

I didn't do a great job clamping during glue up.
It ended up with a few little gaps between laminations.
But they dont go all the way through, and they are all in non-working sections of the bow.
So i just filled them with more Unibond, and I'll pray that it holds up.  Is the bow dead on arrival, or is it still salvageable?

I just realized that i never put a pin in the Z splice... a little dowel inserted horizontally through the splice. 
I don't see why i couldn't just drill that in now.  And looking at the pic now, the bamboo looks thick to me. 

Also I'm uncertain as whether i should keep the recurve static or dynamic.  With a 30" draw length i may need the extra length of working limb.
But I'm thinking i can tiller it static for now, and should i need to i can always tiller down the tips to get them working, maybe semi static at least.
This gets me thinking... how can one tell if a given tip angle will be a true recurve... as in whether the string will touch the belly or not? There must be a design principle that uses geometry to predict what recurve angle/ length will result in string-on-belly.

I made a tillering Gizmo I'll be using for the first time.  But with the recurve that may complicate things?  The curve is very sudden,, all of the bend happens within a couple inches.  So maybe I can use the tillering gizmo up the working limb untill just before the bend starts?  And i know you cant really use it close to the riser fades either.  I think i'll have about 23" of working limb on each side, unless i allow the recurves to bend which would add another 6".

I'm about to glue on the 8" riser and tip overlays, then I'll start the tillering process.
Please don't hesitate to tell me if you think i made a big mistake, or i'm headed in the wrong direction.
My skin's thick... I just want to end up with a decent bow.

here's the dimensions:  1.5" wide, then the last 12" narrows down to the tips.  It's 66" long tip to tip, following around the curves.  Theres plenty of belly thickness for me to tiller.  I'm worried that i should have gone wider than 1.5"... it looks so narrow to me.  Maybe I'll need to keep the draw weight down to compensate???

[Springbuck]

  You don't need to pin your splice.

  I sometimes clean up a small glue gap and drive in little splints of veneer with more glue, which works well.

If it's an actual RECURVE, where the string will lay against the limb while strung, leave it STATIC.  If it's a reflexed tip, it can work into the reflex. Yours is a pretty sharp bend, not huge, angle, but all in one spot, so I don't know what to advise, except to say it isn't taking up much of the limb length, so your plan is pretty good.  Run the bend right up to the base of the curve, but be careful because it's easy to create a hinge there (on the belly bump left where the angle is) just by being careless.  You can get it too thin, and it won't show until you get it to several inches of draw.    Just sneak up on it.

"This gets me thinking... how can one tell if a given tip angle will be a true recurve... as in whether the string will touch the belly or not? There must be a design principle that uses geometry to predict what recurve angle/ length will result in string-on-belly."   I just sketch them out in miniature on graph paper with a ruler and compass, but your angle is too low for a"real" recurve, just to my eye. 

A tillering gizmo is a good idea, but remember to let the front profile tell you how to tiller.  Since the sides are parallel a long way out, you should bend the outer limb below the recurve more than near the handle.  Parallel sides mean thickness taper is appropriate.

  1.5" is fine, but, yes, with a bamboo back and black locust, I would have gone wider (if I had the material) and trapped the limb.  But, it's fine.  Good tiller makes good bows.

[Danzn Bar]

Wow, you have put a lot thought into this bow.....keep it up.
DBar