?'s about Bingham's T/D Pronounced longbow and .060 E-glass

[Kevin Breaux]

Disclaimer: I am a wood hack at best, without a notebook of thickness info for bow designs.

     But, I have started one, with the first being the T/D recurves. I have made a few Bingham's T/D recurves and have a working knowledge of how changes made to the riser length, wedges and limb length/width changes the out come of the bow. I do have all of the Bingham's plans with their lam thickness recipes for success, but I would like to hear from everyone that has made the Bingham's pronounced T/D longbow. When you recieved your limb package from Binghams, what were the total thickness of the glass, parallels and tapers, as a whole and individually. Also the wedge length in each design. I am courious to learn the thickness for all of the Prononunced T/d longbow models, 64',66'.and 68'.

I am at the stage in my building, where I want to start experimenting. I could jump in with both feet and start swinging for the fence, but I'd like a good jumping off point.

***Also, I came into some clear E-glass at .060, is there a particular style limb/bow design the .060 glass is used with, or would you thickness sand it down to a thinner thickness and use it?

  Thanks all for reading and replying,

                             Kevin Breaux

Edit: changed thickness planed to thickness sand

Thanks Kenny

[kennym]

I've only been in on one of those,so can't help you much there,but most bowyers keep glass at 20 to 25% of total stack.

 .060 glass sounds mighty thick for most bows,keep in mind glass is stiffer per thickness than wood.

I don't think a planer will work for thinning glass,will probably splinter it.

JMHO

[PV]

If you use the same lay up of reverse tapered lams and the wedge they recommend Binghams charts are very close in # for their design.

Been making my own lams for years and use a different combination of taper than binghams. Didn't keep good records back in the days I used their lams so I can't help you there.

If memory serves me correctly  binghams design will increase 7# for each decrease of 2" of bow lenght using the same stack height.
You can call and ask they will be more than happy to help you with your ? on their designs.


I'd grind the glass down.

[Mike Most]

I have done two take down longbows, with the pronounced R/D, one a 38# 68" and a 43# 68", both had reverse tapers with 8 1/4" wedges, the first was .265 and the second .282 measured on the thick end 1 inch in. Hope it helps

Good Luck

Mike

[Kevin Breaux]

Could you look this over and suggest changes as your experience dictates, thanks. The bow I am shooting for, is from the Binghams (bow form) for Take/Down 68" Pronounced Longbow, Reflex/deflex. As per Binghams recipe, a Pronounced T/D 68" longbows stack measured w/o wedge calls for .305 for 50#s @ 68"

1.) I do know this stack calls for a 8.25 length wedge, but I am unsure of the thickness, would 3/8ths be a good starting point?

2.) What is the percentage difference from parallel to tapers, (normally?)


I am making all the lams and wedges, this is what I have so far:


This is for a 32" lam stack
Glass          .040                .040
Taper          .124                .060
Parallel       .041                .041
ReverseTaper   .060                .124
Glass          .040                .040

               .305                .305

[PV]

1.) 3/8 is the thickness of the binghams wedge

2.)  IMO it makes no difference % wise as long as the total taper(in this case parallel) is reached. When glued together the lams act as a unit.


Good luck and keep us posted.........

[Kevin Breaux]

Still grinding