Bow riser how to create a good profile to fit lams......

[RT]

Hi, i have built a few bows and am still learning the trade. Please help me with the following.

- I am building a 58" boo, core, raiser, boo bow of 40 lbs at 24", my raiser is 12 1/4" long.
- I would need a min one inch raiser in order to cut in a shelf.
-I have fail on my previous same speccification bow as the fade out is too adrupt thus causing a bad hinge one inch after the fade out on both limbs.
-have been told to make the fade out more gradual at least 3 inches into the middle of riser and at the point 3 inches, the thickness should not be more than 1/4 "
-I find it hard to keep that 1 " raiser if I did the long taper in. And the profile of the raiser will not conform to the lams. Need help on this area.

secondly, after final tillering, If i cut in a raiser of 1.5 inch from the middle. Towards the fade out area, at what point does the limbs stops bending 1/4" 3/8" ........this will tell me how far I can cut in for the raiser from middle towards the fade out area.

Hope I have explain clear enough, if not please feel free to ask. Thank you for your comments.

[mikekeswick]

Just use thin multiple lams. 3/8ths thick will bend to fit. For your other questions we need pictures for a good answer.

[adb]

Yes, pics of what you're doing are always good.

If you're doing a bow with a non-bending handle and a built up riser, try to taper your riser out smoothly into the limbs, and also try to keep the fade outs thinning into where the width of the limb begins to taper on the back profile.

I often go with an 8" riser, and then make each extra lam in the riser 1" shorter, with the grip riser 6" and then reduce that to a 4" handle. If you gradually taper your riser lams down to the limb right where the fade outs are, you won't get a hinge there. A short, steep or abrupt transition at the fades will usually give you problems. I hope I have explained it clearly? Pic speaks a thousand words.

[DarkSoul]

So your question basically boils down to: "how do you make a stiff handle that allows for a cut in shelf in a bamboo backed bamboo bow?"

I hope this picture will give you an idea:


A boo backed boo tutorial is to be found here.

[Jesse]

I find it very helpful to add a short piece "power lam"  between the back and the handle. This piece should be tapered and extend 2 to 4 inches past the end of your fades. This is if you are glueing the handle directly over the belly. If you are doing it like DS just posted its not necessary at all. Just taper it out gradually.  I like my riser for this style to be between 18 and 22" long remember some of the riser on this style and some of the power lam on the other does not remain stiff but bends as part of the working limb.

[RT]

[RT]

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