Tri Lam Question

[Dan Landis]

Roy, how wide should I trap the back, and can you explain what you mean by lower the belly facets.

[Roy from Pa]

I usually trap in about 3/16th from the edge of the limbs. I take the belly facets down to the core lam glue joint. I take the belly facets in about 1/4 inch from the side of the limb. Then round off the crisp edge caused by doing the facets.

[Dan Landis]

Thanks Roy!  Makes sense now, we'll see how much flex that gives me.

[Bowjunkie]

Dan, make sure your front/width profile is absolutely spot on first, except for a little extra width in the tips perhaps until alignment is verified, otherwise, if you start trapping and faceting with uneven widths/wavy edges, it can throw the whole works off.

If you go back and take the wavyness out AFTER you trap and facet, it will change their proportions, then you have to fix the trapping and facets anyway... so, better to bring the width to very accurate profile first. Maybe it already is, I just thought I noticed a few little spots so thought I'd mention it. Carry on.

[Dan Landis]

Thanks Jeff, I checked the limbs with a straight edge from the tips back to the end of the 6" parallel portion, there are 2 areas where it was slightly high.  Straightened them out and trapped and faceted one limb.  Still need to loose a lot of weight, can barely get any movement when floor tillering/bending.  

Right now the limb that is trapped is 1-3/8" at fades, parallel for 6" then tapering to 9/16" at the tips.  Would it be better to make limbs narrower or remove wood from the belly?

[Roy from Pa]

1 1/4 at fades to 1/2 at tips. Then redo the trap and facets. If it's still too stiff, take a rasp and flatten the center of the belly equally, then round over the 2 edges you get from doing that. That is if you have enough belly thickness. You should cause your belly lam was 5/16th to start. I make my belly lam 1/4 thick.

[Bowjunkie]

Dan, I don't know what your target draw weight is, but if memory serves, 1 3/8" is wider than any BBO bow I've made. Do like Roy said and narrow it, maintaining good accurate edges and trap it again. Verify or remark an accurate centerline before you begin to ensure you don't remove more from one side than the other.

You should get a little movement floor tillering before you even put the belly facets on.

For reference, I've made a slew of BBO bows from 60-70# @ 28" that were barely 1 1/8" wide.

If it's still too heavy, don't go more narrow than 1 1/8" or so without critiquing and possibly working down its thickness.

[Dan Landis]

Jeff, target wt. is low 50's.  So far I've narrowed it to 1-1/4", trapped the back, re did my center line, and cut new facets on the belly.  Still feels pretty stiff, but getting some movement.  The osage on my top limb is slightly thicker than the bottom, so I'll start removing a little from the belly on that limb first, then go from there.  Also, need to do the tip overlays and cut in the string nocks.

[Dan Landis]

Just thought of another question, how do you finish out the handle area?  I made this one 13" as in the last build a long that Roy posted.  Do you let it a full 13" or is it shortened as you shape it.  A little shorter would give me more working limb.

[Roy from Pa]

It gets a little shorter but not much.

 

 

 

[Dan Landis]

Thanks Roy, I sort of assumed that was how it was done, but just wanted to make sure.  I'm really trying not to mess this one up.

[mikkekeswick]

How thick are you at the fades, mid limb and at the tips?
Have you had the long string on to give you a reading of the drawlength at your intended finshed weight? If so how far with a taut to the belly longstring?

[Dan Landis]

Mike, I have not put a string on it yet.  I just glued the tip overlays on today.  Right now it measures about 3/4" at fades, 5/8" mid limb, and 1/2" at the tips.

[Roy from Pa]

That's a little thick, Dan. The bow I'm working on now is 11/16th at the fades, 1/2 at mid limb, and 7/16th at the tips. It's 61 tip to tip and pulling 57 at 28". If it was 64 tip to tip, it would be pulling about 50 pounds.

[Dan Landis]

Sounds like I need to remove some wood from the belly and re do the facets.

[Roy from Pa]

When you remove wood from the belly, be careful and make sure you have a nice even taper from fades to tips. Go slow and do not make any deeper areas along the way. That's how hinges start.. Put the bow in a vice and kneel down and look across  the belly surface. Take off any high spots first before rasping the entire belly. Then proceed making the belly a little thinner. I'd start out removing 1/16th of material first. Then redo facets, etc and check floor tiller.

[Dan Landis]

Well, after removing some wood from the belly of both limbs I found 2 pin knots across the limbs in the osage.  The first one is about 3" out from the fade and the other is about 10" in from the tip.  The one close to the fade I think will be gone till I get it tillered, the other one is still fairly deep.  Hopefully it will survive.

[Roy from Pa]

I hate when that happens.  Is the Osage 1/4 sawn?

[Dan Landis]

Yes, I cut it on my table saw.  I cut around  several others, but didn't notice these.  Any hope it will survive, or am I wasting my time?

[Roy from Pa]

I doubt it will. Ya have pictures?