66" flat or pyramid bow, 29" draw length? Will it work?

[Ben Cooper]

Hi all, this will be my 1st time building a bow and I have decided to make it from a board...I stupidly bought a 1675mm (just shy of 66") spotted gum board (Australian hardwood)... My intention was to build the bow at 68" since my draw weight is 29".
Will a 66" flatbow (64" ntn)/ pyramid bow be suitable for a 29" draw length? The board is 3/4" thick.



Thanks all!


Regards
Ben

[bubby]

Ben if you have a good board it will work, go to the how to section and read bubbys easy board bow build that will give you dimensions

[Ben Cooper]

Thanks Bubs, I was looking at your build earlier tonight.


Regards
Ben

[scp]

The longer, the easier. You can simply lengthen the bow several inches by adding longer tip overlays. But if you are not up to gluing tip overlays, just make the handle bend a little. What is the draw weight you want? For less than 40 pounds, you can even have a stiff handle. How wide is your board? I would start with 2 inch wide board.

[gifford]

The Wood Data Base website lists Corymbia maculate (spotted gum) as having a specific gravity of .71, nearly that of Osage Orange (.76) and higher than Pignut Hickory (.66). And spotted gum has commercial uses of flooring and decking. So it should be suitable for higher weight bows, provided you have the right board.

That's a rule of thumb, subject to the usual disclaimers, ymmv.

Dividing the board/stave length by 2 give you the draw length with bendy handle bow. If a handle is used; 6-9 inches from the board length, then divide by 2.

Again, ymmv.

Good Luck.
G

[Joec123able]

Actually, Osage ranges between .76 and .86 specific gravity.

[gifford]

Osage orange upper range of specific gravity actually is .91 with moisture content of 12 percent.

[bradsmith2010]

the pyramid will work,, if it was me I would leave it a bit wider mid limb and then narrow to the tips,, just to have a bit more wood working,,  it might not shoot as fast,,but the bow would be a bit more forgiving as far as the draw length,, just more wood to take the bend,,at the 66 inch length,,

[loon]

was thinking of 66" hickory pyramid 70#@28.5" bow with a nice narrow bulbous handle (tillered to 29.5"?

[Ben Cooper]

The longer, the easier. You can simply lengthen the bow several inches by adding longer tip overlays. But if you are not up to gluing tip overlays, just make the handle bend a little. What is the draw weight you want? For less than 40 pounds, you can even have a stiff handle. How wide is your board? I would start with 2 inch wide board.

SCP, I was actually thinking about gluing some tips on with the thought of reaching 68", do you think it would work? gluing an extra inch on either end and making the ntn length 66" instead of 64", the nocks will start where the original board finishes (will this weaken the tips?)... as for draw weight, 45 - 50lbs (40lbs will be Ok), it will mainly just be for shooting targets etc... Board width ATM is 80mm (just over 3"), i planned on having my widest point 2".

Dividing the board/stave length by 2 give you the draw length with bendy handle bow. If a handle is used; 6-9 inches from the board length, then divide by 2.

Sorry G, this sort of went over my head?? So if i understand you right, the draw length of a 66" bow can be up to 33"? the part with the handle i do not understand at all? can you elaborate? i will be adding a riser, the handle length would be roughly 4" + 2" fades.

the pyramid will work,, if it was me I would leave it a bit wider mid limb and then narrow to the tips,, just to have a bit more wood working,,  it might not shoot as fast,,but the bow would be a bit more forgiving as far as the draw length,, just more wood to take the bend,,at the 66 inch length,,

Thanks Bradsmith, what width would you do for the tips? 1/2" seems to be the standard... i was thinking 2" wide at the widest then narrowing to 1/2" at the tips?



Thanks again to all that have replied and offered help!


Regards
Ben

[bubby]

What he means is ntn length of 64" - 8" for the riser then divide by 2", so 56"÷2=28" with that final number being the safe draw length

[bubby]

Ben you can glue a 6" pc on each tip and overhang it an inch or so, you need a good gluing surface, then radius that from the back of the bow to the top of the overlay and match that on the bottom and you can get a little more draw length

[Ben Cooper]

Ben you can glue a 6" pc on each tip and overhang it an inch or so, you need a good gluing surface, then radius that from the back of the bow to the top of the overlay and match that on the bottom and you can get a little more draw length

Thanks Bubs for clearing that up... just to confirm, you glue the extra 6" tips to the back or the belly?

What he means is ntn length of 64" - 8" for the riser then divide by 2", so 56"÷2=28" with that final number being the safe draw length

Great! thanks Bubs!




Regards
Ben

[bubby]

Glue to the back

[bubby]

 Like this ben