Getting lams to meet Riser profile

[robin]

Hi, I am building a boo back and belly bow 58" long, The details of the setup are append.

Boo- 1/8 thick
core- 1/8 thick
raiser- 12 2/8 long, thick 6/8" and wide 1 1/4
Boo- 1/8 thick

Problem, I am having problem to get the lams to wrap nicely around the profile of the raiser. After clamping down, i could still see small gaps between the lams and the risers. these gaps are approximately 0.5mm wide.

Questions, how do i get the lams to wrap nicely around the profile of the raiser?

Attached are some pics to help you visualize better. Advise? comments? suggestions?

By the way how do i add pics?

RT

[robin]

https://drive.google.com/?usp=chrome_app#folders/0B3mNHyOexIB5dkJ5SzJvTk9UQXM

[robin]

This should be the correct pics, please ignore earlier link..........

https://drive.google.com/?authuser=0#folders/0B3mNHyOexIB5dUYzaWpDSHBnMkE

[LittleBen]

You can add pics by uploading to photobucket and pasting the link here.

The short answer, better clamping.

It may take a quite a few clamps to get 1/8" lams to comform.

Just a heads up on the bamboo back and belly

You need to taper all of the lams before glue up. Some people pre-tiller each lam indivdually, some just add a taper to each.

Yoiu can do some tillering on the belly of a bamboo belly bow, but not a ton. Most tillering is done with the side profile. So your tiller needs to be fairly close before any tilering.

I think that you may find the easiest thing is to just make a slightly thinner riser. maybe go to 1/2" and just add another riser block on the belly side if you need to build the handle up a bit.

Lastly, my only experience with bamboo on th ebelly tells me it takes alot of set compared to most hardwoods.

I'd think at that length and width of bow, if you start with a straight limb you will end with alot (3"+) of string follow.

Might want to raise the tips up a bit when you glue it.

[robin]

http://s43.photobucket.com/user/robt188/media/Boo%20Bow/05112008008.jpg.html?sort=3&o=1

[robin]

http://s43.photobucket.com/user/robt188/media/Boo%20Bow/05112008008.jpg.html?sort=3&o=1

hope this works, ignore earlier pix.......

[robin]

http://s43.photobucket.com/user/robt188/media/20140326_210300_zps1ef8f05f.jpg.html?sort=3&o=0

[LittleBen]

You need a much more gradual taper. You really need to fade into the limb very smoothly.

The riser block should be almost paper thin where it ends, and needs to blend as smoothly as possible all the way to the middle of the riser. No both back and belly.

The less curvature the laminations need to make the better that they will fit.

[fujimo]

[Zradix]

yep,

looks like you have some angles that are too sharp where your riser starts thinning down. Make it more gradual and rounded.

I respect your want to use that traditional clamping technique..but you may have to experiment a bit more to get enough pressure in your problem areas...a c- clamp or two wouldn't hurt.

Maybe thinning the back and belly a touch just through the riser to help it bend a bit easier would help....

Hard to tell from the pic..but as Ben mentioned...get the the tips THIN. Like paper thin....see light through it thin.