Lets talk tri-lams.

[Prarie Bowyer]

Grrrr...

I can't seem to to get to dimensiton that resemble a long bow in three layers with out the built up grip area. 

What the heck is it with me?  I'm getting closer. 

What I'm aiming for is a simple bamboo backed "sumptin (purple hear, bamboo, yellow heart, Ipe... ) with a hickory or Ipe belly.  No extra clump glued on for the handle.  Unstrung should look like a stick.

I'm getting closer but how the heck are those other guys getting there.  I feel like I get so much extra strength from my glue lines that I build a club.


So if anyone is willing to share dimentions and thicknesses of laminations that would be lovely.

[mikekeswick]

Backing upto 1/4 thick, core upto 1/8th, belly thick enough to make the total thickness upto 3/4 - 7/8th at the handle.
Gluelines DO NOT add stiffness, if we are talking about a standard glue-up then thickness determines overall stiffness. Remember to double a bows draw weight you only have to increase the thickness by an 1/8th.

[Prarie Bowyer]

What about gluing in reflex?

[mikekeswick]

What about it?

[Prarie Bowyer]

Thoughts?

[Ian.]

I feel like there is a question missing, was it - how much weight would be gained by re-flex?

[Yeomanbowman]

Thoughts?

Too much reflex on a bow of this sort will lose weight as the wood will give up if overdone.  It also really effects stability in an ipe belly bow as it often wants to cast off to the side.  With a heavy laminated longbow, I have found a little reflex goes a long way. Say 1" or so. 
I made a 4 growth ring ash/mass160lb longbow with a straight glue up and it didn't follow the string over much.

[adb]

I've also found heavy draw weight bows to be rather unstable with even a little bit of reflex. I had to abandon an ipe bellied tri-lam cuz I added a bit of reflex, and I couldn't brace it early on without it rolling over. Shame, it was looking like a decent bow. From now on, no reflex on warbows for me.

[mikekeswick]

The other guys have covered it!
I have many,many thoughts about reflex....
Specificity is a great thing when it comes to asking questions 

[toomanyknots]

I've also found heavy draw weight bows to be rather unstable with even a little bit of reflex. I had to abandon an ipe bellied tri-lam cuz I added a bit of reflex, and I couldn't brace it early on without it rolling over. Shame, it was looking like a decent bow. From now on, no reflex on warbows for me.

Were you trying to brace it at a low brace? I find any narrow profiled reflexed bow can be ustable, regardless of draw weight. You gotta give it a high enough brace to be stable from the start. It probably is more unstable the higher the draw weight though. The way I tiller a bow like this, is to use a mirror, step on the tillering string, and pull up. That way you can hold the bow stable when drawing it, until you get it to a high enough brace height to be stable and it wants to calm down and be a bow.

[Prarie Bowyer]

The other guys have covered it!
I have many,many thoughts about reflex....
Specificity is a great thing when it comes to asking questions 

What if there is information that i could use and don't ask THAT question.  Basically I was getting at is it necessary?

I finished the bow up with about 2.5" of deflex... glued it up flat.  Next one I'll thicken the core... thin the belly at the center  and glue in about 2" of reflex if using Hickory sap wood. 

Ipe dosen't need it I know.

[bow101]

I've also found heavy draw weight bows to be rather unstable with even a little bit of reflex. I had to abandon an ipe bellied tri-lam cuz I added a bit of reflex, and I couldn't brace it early on without it rolling over. Shame, it was looking like a decent bow. From now on, no reflex on warbows for me.

Thats strange you mentioned "Roll over" adb.  I always wondered 'bout it but never did ask anyone on here...   Have you ever had a standard type bow roll over on you..?

[adb]

Nope.

[Thesquirrelslinger]

I've also found heavy draw weight bows to be rather unstable with even a little bit of reflex. I had to abandon an ipe bellied tri-lam cuz I added a bit of reflex, and I couldn't brace it early on without it rolling over. Shame, it was looking like a decent bow. From now on, no reflex on warbows for me.

Thats strange you mentioned "Roll over" adb.  I always wondered 'bout it but never did ask anyone on here...   Have you ever had a standard type bow roll over on you..?

I frequently roll over the bamboo recurves I make, they are for little kids, they pull around 15-20 pounds, are bamboo, 2 layers.
If I make the limbs too narrow and the recurve too severe, I generally end up with a twisted piece of crud.
If I make the limbs wide enough, they shoot good.

[AndiE]

Hi

What would be the best combination for a trilam?
I think hick-osage-osage!
What Do you guys think?

Greetings
AndiE