question for laminated bows

[JamesKerr]

I am new to making laminated bows and would like to know what effect does the number of laminations in a bow have on its performance also how does a trapped design on a hybrid increase performance

[jess stuart]

This is kind of  a general question.  So my answer will be the same, others ideas and opinions may vary.  More lams equal thinner lams, if one lam has some sort of internal problem, the thinner it is, the smaller the total percentage of the limb it is.  Trapping helps to rid a limb of mass that is just along for the ride, increasing performance.  Go to far and stability issues can occur.  Remember this all just from  my limited experiences, take it for what it is worth.  Your mileage may vary considerably.

[jsweka]

The number of lams was recently being discussed in another thread.

 http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=005333

[JamesKerr]

thanks for the input also when you use tapered laminations does the core wood need to be a parallel tapered lamination

[jess stuart]

It would probably depend on design.  Some bows use all tapers others all parallels, most I think use a combination of tapers and parallels.

[Sixby]

When you glue both sides of the laminatin you trap it verticaly. Then when you bend the bow the wood fibers are stretched. Imagine them leaning instead of being at a 90 they now are at like a 60. The thicker the lamination the more this is exagerated,. the thinner laminations are bending to a lesser degree and the stress is more evenly distributed between laminations. The wood is worked less. It lasts longer and it also performs better. It returns to its origonal position faster. The bow is also less likely to take any set. When I pull mine off the forms I can lay them right back in the forms and the lay perfectly flat. When I used fewer lams for the sam amount of stack the limbs would not lay back in flat to the forms. That is because the wood fibers were giving to the pressure. Imho no lamination should be more than .050 unless it is a taper then you can have it say .075 tapering down to what the parallels are.I usually end up with 6 to 8 laminations in a limb. God Bless and good luck, Steve

[JamesKerr]

thanks alot guys Sixby you said you usually end up with 6 to 8 laminations in the limb do you need to have more laminations on the back side of the riser or should they be on both sides of the riser