Skinny pyramid bow?

[Tommytinker]

I have a 1.5 x 1 x 71 inch hickory board.

I'd like to try a skinny pyramid style bow.

Has anyone tried this style so skinny?
Is 1.5 inch too thin to start the taper?
How thick would I leave the limbs to archive 30 - 40lb at 28 inch draw?

Any help would be appreciated.

If it helps to know, I'll be backing with rawhide.

Tommy. 

[Marc St Louis]

I think you mean 1 1/2" wide and no it's not too narrow.  I've made them out of HHB at that width

[Wooden Spring]

I just made a couple of hickory backed purpleheart bows for my wife, both of them were just 1" wide at the fades... Here's their numbers for you to compare with. I would suspect that a hickory self-bow would have similar results.

Hickory backed purpleheart

Bow #1
68" tip to tip, 1" at the fades, 7/16" thick, 34# @ 28"

Bow #2
62" tip to tip, 1" at the fades, 3/8" thick, 20# @ 25"

If you made your hickory bow at a full 1/2" thick, you'd hit your target weight.

[Pappy]

I make a lot of Hickory 1 1/2 at the fads,68 inches and can get close to 50 @28.
Some say Hickory needs to be wider but I like them better at 1 1/2 or 1 5/8. I usually start at at 7/16 to 5/8 in thickness and for what you are talking about that should be more than enough,maybe a little thicker to start because of the length
you want. Remember keep it dry ans slow and easy on the tiller.
  Pappy

[Tommytinker]

Thanks guys, very helpful.

Glued a red palm riser on her this morning. I'll start roughing out tomorrow.

Just to clarify, 1.5 is of course the same as 1 1/2
Have I missed something?

Perhaps it's just me, I use digital callipers to check my depths and they read in decimals.
Tommy.

[JW_Halverson]

Yup, inch and a half is same as 1.500.  I use a dial caliper, too.  Not because I need that kind of accuracy in the thousandths, but because I hate working with fractions!