Traped?

[Knawbone]

Saw where some of you were talking about traped limbs. I didn't see it in the def. of terms, Could someone explain please- Thanks

[don s]

it's where you sand the side of your limbs at an angle. some do it on the belly and some do it on the back. also depends on if its a glass bow or an all wood bow. trap is short for trapezoid(sp). your limb cross section goes from rectangular to trapezoid.
                        don

[beetlebailey1977]

Yep it helps keep the back from over powering the belly...basically.  You chamfer the edges real good in order to weaken the back.  A lot of folks do it on a all hickory bow.

[JamesV]

what Don said

James........

[Knawbone]

Thanks guys, Iv got it, much appreciated

[CaptainJ]

Ahh, traped as in trapezoid?


CJ

[SEMO_HUNTER]

Don't know if it's right or wrong, but the short Indian flatbow I just made is traped on the belly. More so than the back anyway, and I wouldn't call it a true or perfect trapezoid shape? More of a round taper from back edges toward the center of the belly and it turned out better than I could have ever expected. It's also PDQ (pretty dang quick) for a 40# @28" Osage flatbow. I just did it because I liked the looks of the shape better than square or rectangular. I like how the ring just fades gradually around the edge of the bow limbs and into the center of the belly. It shoots like a dream for such a simple design.

[Pat B]

For wood bows trapping is generally in favor of the belly meaning the belly would be wider than the back. This would decrease the effects of tension and add to the compression effects of the belly.
 Glass bowyers use trapping also but some trad towards the belly and some towards the back. It is incorperated into the design of the limbs for different performance qualities.

[Knawbone]

Thanks again guys, Im playing with the idea for my first bow. It started out as a self bow from a 2 to 3 in. sapling. Because it had such small growth rings I was unable to chase a summer ring. Anyway I decided to shave the back flat and back it.With great advice from one of the Gang it will be maple backed ash. Thus trapping the limbs(back} so as not to overpower the ash belly. If I'v done my homework correctly this should work out well. Im just guessing on how much to trap it? Probubly will heat treat the belly as well- how my doing so far Pat. The other reason for trapping the limb edges in my thinking is to decrease the likelyhood of limb twist or warpage and for making them more ridgid as the limbs are very narrow. Any advice or comments on my train of thought is more than welcomed. thanks for all the great advice everone-this site is awsome,Bone

[highplains55]

i have 4 glass backed longbows that came trapped on the belly side,and have shot bows that were trapped on the back both have shot great for me,i have personally trap tillered bows to reduce weight up to 5 pounds and they shot better with less handshock while retaining cast,great way to go.

[Pat B]

Knawbone, sounds good but be sure to temper the belly before glue up. The heat will deteriorate most glues. You will have to pretiller it first to insure the limbs bend evenly and together.
 I have trapped a few wood/boo lam bows I was building to relieve the tension stresses when the bows began to take on set while tillering.

As far as how much trapping it all depends on the woods used. Start out making the back maybe 1/8" less than the belly. If you find you need more go a little more but don't over do it.

[Knawbone]

Thanks Highplains and Pat, Pat I will have to skip the heat T. as I don't trust tillering without the backing on, however I have noticed that the Ash does get harder on the surface by scraping it very smooth. Thanks for the heat warning- I hadn't thought of that.