BBI recipe?getting ready to tiller...

[Schmidtster]

I'm going to tackle my first BBI I'm going for slight reflex or straight after tiller. What I need is a template I'm not sure how thick to make the boo and ipe. I'm wanting a 50 pound bow. I'm thinking 1/8 boo and ipe starting 1/2" thick, than tiller from there. Is this too thick? Should I taper the thickness of the boo or ipe?

[Roy from Pa]

When I make BBO bows, I taper the boo from 1/8th at center to 1/16th at tips. I taper my 1/2 inch Osage belly  slat from 1/2 at the flares to 3/8th at the tips. Make sure you pad the back of the boo so the clamps don't indent it, or it will splinter while tillering. My form below for r/d.

 

[macbow]

On my BBI I flatten the bamboo. Then put it in a heat box to,assure it is dry.
Then trace out pattern, cut it out and reduce the flat side till the edges are 1/16 thickness.
For 50 pounds the 1/2 inch Ipe should do well.
I recommend the form and design layout that Roy showed.
I just use different clamping.
Ron

[Schmidtster]

Thanks guys I will give it a shot I have a form like Roy's made up I tried a maple backed maple R/D but it blew up on me so I think I'll just go for slight reflex.  And I think I will taper the ipe to help with the handle transition into the fades so it doesn't pop off lol.

[macbow]

I like to glue my handle on as a second glue up.
I use several slats 1/4 or less. These are glued up after the first glue up is cleaned up.
I like this because I think it helps with keeping the,handle from popping off.
I also prefer using a power lam between the bamboo and the Ipe own the first glue up.

[Saltfork]

Great form Roy.  Would you mind sharing the dimensions?

[Saltfork]

Great form Roy.  Would you mind sharing the dimensions?

[Roy from Pa]

Good point Ron on tapering the edges to 1/16th, I do that too, maybe even thinner.
My center post, which is placed in the center of the handle is 3 3/4 inches high. My two mid limb posts are 2 3/4 inches high and you can place them where you want, depending on how much deflex/reflex you want. The closer you place them to the handle the more deflex and less reflex, the closer to the tips the more reflex and less deflex. Placing them at exactly mid limb from the flares is a good place to start and what I do most of the time. My end posts are 6 inches high. Hope this helps you out, any questions just ask. Also I flip my tips before I glue the boo up. The bow below has flipped tips before glue up and the mid limb posts at exactly mid limb.

 

 

Below is how I taper my riser to fade into the limb. I have never had a riser pop off.

 

Below is how I flip the tips.

 

[Schmidtster]

That's awesome! Think that form will work without flipping tips? I'm kinda trying to cut out some possibilities of me messing this one up haha. Also any ideas on a handle size, the way your doing it Roy looks good to me. I'm thinking 4 inch handle with 2" fades should work for a 64" ttt bow. Correct me if I'm way off please.

[Buxndiverdux]

Nice looking stuff there Roy from PA...  

[macbow]

Since I'm using IPE I don't flip the tips.
My post heights are different than Roy's but the same ratio.
I know you are Leary of the R/D but it is a smoother shooting bow. Less hand shock.

The main difference in tillering is in the reflexed area more material has to be removed to get it bending. Then small amounts of removal make a,bigger difference.
I still use Eric's gizmo after the r/d area starts bending.

[Trad Dad]

macbow, what post heights do you use for IPE?

[Roy from Pa]

You don't have to flip the tips, all it does is give it that sexy look, add a tiny bit of weight maybe, and will help reduce the string angle.

I make my riser 13 inches long and my bows equal length limbs. I place the center of the 13 inch riser at the very center of the bow, measured tip to tip. From dead center I measure up 1 1/2 inch, that is my arrow shelf. I measure down 2 1/2 from dead center and that is the bottom of my grip. That gives me a 4 inch grip for my leather I wrap around it. From dead center I also measure up 2 1/2 and that is what I call the top of my handle, not my grip. Can become confusing:) From dead center I measure up and down 4 1/2 inches, that is my flares, widest part of the bow! From the flare I measure out 2 more inches, that will be the end of my riser where it tapers off onto the limb.  

I like Ron also glue on the riser after the belly slat and boo are glued up and dry. The belly slat and boo glue up in r/d form will bend the center of the bow a little, maybe 1/4 inch. After I take the bow out of the clamps, I take my 13 inch riser section and lay it on my work bench on it's side. I lay the bow on it's side on top of the riser, keeping the center mark of the bow and center mark of the riser lined up. I then trace the curve of the bows belly slat onto the riser. Cut that out, rasp or sand to get a perfect fit and then glue on the riser.

AND DO NOT CUT THE BOW OUT TO SHAPE, UNTIL AFTER THE RISER IS GLUED ON AND DRIED!

Hope that all makes sense. Would be so much easier just to show you guys hands on. Ah hell, just drive on out here to Pa and we will do it:) Or go see Ron in Missouri. LOL I know, it's just not that easy....

[Schmidtster]

That is great info!!! Beside physically building my bow you are doing all the work hahahha. Thanks alot for all your help I really appreciate it.

[macbow]

Trad  Dad, my end post are 5 7/8 inches.
Center is 4 inches.
Mid posts are 3 3/4 inches.
I put my mid posts 16 inches from center of riser on bows from 60 inches to 64 inches.
These are what I've been using this year.
Moving the mid post towards the tips will make it shoot  light arrows faster for target.
The mid limb position is good for hunting and a,heavy arrow.

[Trad Dad]

macbow, thanks for the info. My hotbox is about half complete and I need to figure out the form. Glad I started following this thread.

[Schmidtster]

Hey guys!! I'm getting pretty excited my Ipe and Boo just came in the mail. I laid out my bow for 64" TTT, my handle section is laid out exactly like Roy had explained earlier. I started with a 1 1/4" wide by 5/8" Ipe board. I'm going to rip it down to 1/2" than starting at the end of the flares taper the thickness to 3/8" at the tips to start and help with the bending during glue up. I tapered the width starting at the end of my flares straight taper from 1 1/4" to 3/8" at the tips. This is my first BBI so any suggestions would be very much appreciated. I was wondering after I glue it up and start tiller, do you round the whole belly of the bow into a crown before tiller? or just leave it flat during tiller and round only the edges after?

[macbow]

I like to keep the very edges of the IPE and Bamboo slightly rounded during the whole tillering process to avoid splinters.
When finished I smooth and round,all edges a little more.

[Schmidtster]

So I think I may have screwed up a little. I got my Ipe and Boo. I tapered the thickness of my Ipe. Than I cut out the profile. Is this going to be a problem when I glue up? should I flatten the boo and cut out the same profile before glue up or just leave it the full width?

[vanillabear?]