Laminations

[willie]

so if optimal grain orientation is what makes laminate layups better, how should DC cut the lams for his recurve?

VG on the back and belly, with a flat grain core?

[DC]

Actually I'm just kerfing the recurve so the wood will be glued back where it was, almost, and with a thin insert. Lots of interesting comments though

[bubby]

heh, buddy . . . don't denigrate us manufacturing guys!   

I believe gfugal's points (1) and (2) and Chris' post are correct.

Oh sure, now the engineer chips in 😲 lol sorry mike but i had ta. I also believe chris is correct, as far as the glue being involved with making it stiffer, after all if you just clamp them together the lams are still kinda floppy, but when the glue/epoxy dries whamo!! It's a stiff☺

[PatM]

so if optimal grain orientation is what makes laminate layups better, how should DC cut the lams for his recurve?

VG on the back and belly, with a flat grain core?

 The opposite I would think.

[mikekeswick]

Answer his question if the rest of us are wrong.

Ok, PD I will try to clarify, even if you are talking about something different than the OP.

If "his question" was....

So are three stronger than two?

Then yes, as there are benefits to minimizing defects in the materiel, which is what we do when we swap ends, make multiple lams or build glulams and I-joists. Making a limb with minimized defects  bend further than a comparable limb with the original sized defects, might be called stronger in a sense. More bend stores more energy.

if "his question" was..... 

Is a laminated piece of wood stiffer than a solid piece of the same dimensions?

then, No. The stiffness would not change unless the glue itself had some extremely superior properties.
There are of course, those claims made for Perry Reflex, but I do not think the OP was asking about prestressing the pieces before glue-up.

As above

[mikekeswick]

The simple answer is it doesn't really matter as the difference would be minimal in a recurved portion of the limb. The 'formula' for a non bending recurve laminated or one piece is to make it a shade thicker than the thinnest part of the working limb.

[jaxenro]

One reason I am questioning lamination's is for making stiffer and stronger arrows. When I am only using a 1/8" or 5/32" shaft it isn't all that stiff or strong to begin with. What I am thinking of is laminating a 5/32" square shaft like below then rounding as shown to maximize the glue lines and different woods for stiffness and strength

[willie]

Jax

I can see where smaller arrows would have spine much more succeptable to grain orientation than usual sized.

Have you looked at the hex shaft type of construction? seems like a lot of work for making such a small arrow.

have you tried using very fine grained wood to start with? I have made elipitical crossectioned shafts when one direction or side has a pronounced soft side (spine-wise)

[Badger]

  I started using western larch for my small diameter arrows. It seems to have a good spine to diameter and weight ratio. Allene Case uses tonkin cane and laminates them hollow like a fly rod with six sides. His arrows are used in the majority of records being set with wood arrows.

[jaxenro]

Yup I am trying fine grained wood also but since I need to round it the lamination isn't all that much more work. I am making a jig and since I buy the wood cut to size it is really just five minutes per arrow to make the square shaft then let it dry for 48 hours.

Everything I am doing is a lot of work for a miniature but this is the end result I am building towards (sort of this case looks a bit too modern for my taste)

[Badger]

  That's a cool looking set, what are the dimensions?

[jaxenro]

Not sure Green Man Longbows in England makes and sells them. What I am working towards is a miniature version that will about 24" total and maybe 12 1/2" to 13" taken down.