Hey guys,
Just opened up a box of lams for my first tri lam.
The core lies flat on the table but has a bit of a curve to it.
when I lay it on it's side with one tip on the table the other is about 5/16" off the table. The lam is 62"
Is this acceptable?
I'm pretty sure I can glue it up evenly but, will it cause the limbs to curve once out of the jig?
Thanks.
It should be fine..
hope so..
Thanks Roy.
I guess I'm worried when I cut out the profile it'll go waay off.
Do ya think it's best to clamp the lam straight then draw the outline..or just draw it out on the curved wood and hope it stays straight?
I wouldn't worry too much because when you cut the profile out, you'll probably remove all the problem.
You're only talking about needing to narrow the bow by less than 1/4" to entirely eliminate the curve.
Bring the damn thing to Pa and I'll show ya how to glue it up. Bring Ole Style too:)
Ya don't need to draw nothing on it, your back of your bow should be cut to the exact shape of the tril lam before glue up. Then after glue up and riser glued on, you then cut out the bow along the edge of your backing...
You are making a tri lam, right? So the core lam will be in the center, right?
Thanks for the offer Roy.
Wish I could make it over there man.
I'd have to take the long route through Chicago for the old style...don't sell that round here.
yeah, it's a tri lam.
"Then after glue up and riser glued on, you then cut out the bow along the edge of your backing..."
I was thinking the same about the backing cut to exact shape.
Just thought the core and belly should be close to shape too.
You saying to just keep the core and belly rectangular during the glue up?...that seems weird....
Looks like in the build alongs I've seen the core and belly are at least roughed out to shape...
You have the backing cut to the exact shape your bow will be, before the glue up.
Leave the core lam and belly lam rectangular prior to and during the glue up.
Do a dry run and make sure the backing is straight by running a string right down the center of the backing. At that time I clamp it down and then drill two holes through all three lams in the center of the handle where the leather grip will cover those holes when all done. I stick tooth picks into those two holes when I glue it up. I also drill a hole in the very end of each limb, clear through all three lams. I stick tooth picks into those holes also when I glue it up. Those tooth picks at the handle and tips will keep the backing aligned straight when you glue it up.
After the first glue up dries like 24 hours at 70 degrees, I then make a 13" riser to fit onto the bow. The riser has to be cut in a slight circle to fit the contour of the riser section on the bow, because it will have a bend in it from being glued into d/r. After that glue up dries, then you cut the bow out, staying as close to the edge of your backing as possible, without cutting into it. Then clean up with hand tools right to the edge of the backing.
Ask any questions you like, John.
That's very well explained Roy. Thank you.
Just totally surprised about leaving the core and belly rectangular during glue up. I haven't seen one single pic in any build along that led me to believe that's how it was done....including your build alongs...
Are you just messing with me on that?
I have left practically every single one of mine rectangular shaped (core and belly piece)... same on standard BBO bows. There's simply no need to narrow them, which makes doing so a wasted step.
I keep wooden backing pieces such as hickory rectangular, but to facilitate proper thinning, I do shape bamboo backing pieces to oversized bow dimensions... the limbs, not the handle. I leave the entire handle area full width from flare to flare for layout wiggle room and because there's no need, wasted step... it will be cut to shape after the handle piece is glued on, so why do it twice?
I don't use the toothpick method, but rather, align the pieces with alignment marks on my jig. That way I'm sure nothing moved out of alignment as I bent the pieces down into the form. The more deflex, reflex or recurve induced, the more care should be taken.
Sounds good guys.
This is gonna be fun!
almost ready to glue....
I see why some of ya were making fun of my worry about glue lines where the tapers of all the lams went parallel....lol
....it was all in my inexperienced head... :knothead:
these lams are just flimsy floppy things aren't they...kinda nice to work with... :thumbsup: