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Main Boards => The Bowyer's Bench => Topic started by: rockkiller on February 21, 2017, 07:39:00 AM
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If you take say a .002 tapered lam and leave it parallel for a couple of inchs past where the fade is on the butt end....is that the same as adding a power lam ????
I hope this question make a little sense. :dunno:
Thanks once again for the help
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Not sure I understand what you are saying. You mean, add a 2" piece of .002 taper to the stack right off the end of the fades?
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No
a power lam is a power lam
Most of the time It is parallel to the end of the riser and then tapers to nothing (.000) 3 to 5" or so past the riser.
I use power lams when I take a Take Down design and make a 1 piece bow, The power lams is what the butt wedge was.
My riser will end the sane place the T/D riser ends and then the power lam.
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I will take another crack at this.
If your riser is 18" and if your lam is 36" and you are going to grind a .002 taper on it and if you leave the first 11 or so inches of the butt end parallel then start the taper is that kind of like a power lam.
Sorry if I'm not explaining it very good.Sometimes my grasp of the English language ain't too good as hard as my teachers tried in school. :knothead:
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Right or wrong this is what I have been doing.. If I have a 18" riser.. I take a 24 or 26" 040 parallel and taper the last 2 inches on each end down to "paper thin". That's my version, I think others use a thicker parallel. So I am not tapering the PL until it's past the end of the riser fade.
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I think he is saying "why add a power lam if instead you could just start tapering your tapered lam passed the riser instead of at the center of the handle"
He wants to know if his logic is sound and I am also curious.
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No
The lams is basically the same If you taper it all the way or if you taper it to the end of the fade.
A power lam on a 18" riser would only be 26"? long or so and would be centered on the riser.
It takes preassure off of the fades
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(http://i1293.photobucket.com/albums/b593/osagemark/Bing60/100_0964.jpg) (http://s1293.photobucket.com/user/osagemark/media/Bing60/100_0964.jpg.html)
See the belly glass and lam are against the form.
that means that your form would have to be reversed tapered or it would not fit flat on the form.
So what I did was after making my lams I sanded the belly lams Parallel under the riser so It would fit flat.
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Its not a power lam but it will act in the same way. Kenny made some lams this way several years ago for me. All the PW does is stiffen the area it is place to move the working section further out on the limb.
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ben nailed it !
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So do all power lams start with a .004 taper? Or does it vary with design?
I have only done kennym design,so would a .004 work for that?
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Roberts method would be easiest to do without a thickness sander and a sled.
I'll be open shortly if you need some..... :)
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The purpose of a power lam is to make the limbs bend more further out toward the tips, take pressure off the fades, and essentially lengthen your riser.
My answer to your question is yes, you are correct. What you are proposing will do that so it would act as a power lam BUT at a smaller rate. The effects wouldn't be that noticeable. You would only be getting the benefits of a very thin power lam.
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I always stop my taper 3" from the fades. With the proper taper rate this will put the bend further out the limb and away from the fade.
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""If your riser is 18" and if your lam is 36" and you are going to grind a .002 taper on it and if you leave the first 11 or so inches of the butt end parallel then start the taper is that kind of like a power lam.""
Yes, as Chad says, not as effective as a power lam but will help.
The power lam is an added thickness tapering to 0 that helps the riser.
The .002 paralleled out past riser end moves the more bendy part of the taper out but will not do as much as a power lam added to the taper and riser.
Clear as mud, huh?
:D
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Kennym
So on your design a powerlam would be a .002 taper going each direction from center about 11 inches long for a total length of 22 inches???????
And how thick would it be at center????
I hope I'm not asking to much .
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A power lam really does the same thing as putting a longer riser in the bow. Guys use it to modify riser length in order to customize the bow for longer or shorter draw lengths. If your only building a few bows for your self and friends you can just use a longer riser rather then a power lam.
I use power lams in my goshawk longbow because it requires a 20" riser. I can buy 18" riser blocks way cheaper so I use a power lam to turn the 18" riser into a 20" riser and it saves me at least 10 bucks for my time and makes it look cool if I use a contrasting wood like purple heart. Plus some people probably think I got some special secret going on there and they will pay me more. :biglaugh:
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There is a little confusion going on in this conversation and we need to be clear which side is being tapered to and from. It could be beneficial to say that I'm 99 percent sure that all of the tapers before mentioned are talking about the handle area being parallel and the taper beginning around the fade and tapering to the tip. A few ppl referenced this different ways that could get confusing depending on how you are mentally orienting the lam.
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Originally posted by EwokArcher:
It could be beneficial to say that I'm 99 percent sure that all of the tapers before mentioned are talking about the handle area being parallel and the taper beginning around the fade and tapering to the tip.
draw a simple diagram --it will clear it up
I am not saying it could not be used or that there would not be an advantage to your design....but it will not move the working limb out as a power lam or as a longer riser would
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Bamboo, I agree, it wouldn't be enough thickness to affect the same change as a true power lam. I was only trying to clear up what others were saying.
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Originally posted by rockkiller:
Kennym
So on your design a powerlam would be a .002 taper going each direction from center about 11 inches long for a total length of 22 inches???????
And how thick would it be at center????
I hope I'm not asking to much .
A power lam has to taper to a feathered end from center toward tips of limbs. It can be variable in starting thickness. Say for 11 inches, I'd go with at least .004 per inch, coming to a feathered end just like a fade on riser.
This would make .044 thick at bow center. It could be .060 just as well, or thereabouts.
I like it to be tapering when it goes past fades of riser, but from there to center it can be parallel because the riser is handling it.
Hope that helps! :)