Trad Gang

Main Boards => The Bowyer's Bench => Topic started by: Matt. on April 02, 2009, 10:27:00 PM

Title: First Lam Bow with pictures, Need Advice.
Post by: Matt. on April 02, 2009, 10:27:00 PM

I made my first bow (first two actually!)

I made an oak board bow and a glass lam bow simultaneously. I finished the oak board bow quickly and this delayed the construction of the lam bow because I spent all my free time shooting the oak bow!!

So I need some advice about cutting the riser of the lam bow so I can finally finish.

Specs: 62" 102# at 28" Limbs: 7/16" thick

Here are some pics so you can get an idea of what it looks like:
 (http://i722.photobucket.com/albums/ww225/kalkhr/bow011.jpg)
Riser

 (http://i722.photobucket.com/albums/ww225/kalkhr/bow013.jpg)
Unstrung

 (http://i722.photobucket.com/albums/ww225/kalkhr/bow002.jpg)
Strung

 (http://i722.photobucket.com/albums/ww225/kalkhr/bow005.jpg)
Profile

I think I may have made the riser too short!

It measures 14" long, 5" on the top. Where do I cut the arrow rest? I am afraid to cut into the top limb, as I don't want to weaken it.
If I missed any important information, just ask.

Thanks for your help!

Title: Re: First Lam Bow with pictures, Need Advice.
Post by: Pat B on April 03, 2009, 12:12:00 AM

Grab the handle as if you are shooting the bow. Place a pencil mark at the top of your bow hand. That is where your shelf(arrow rest) should go.

Title: Re: First Lam Bow with pictures, Need Advice.
Post by: Matt. on April 03, 2009, 09:29:00 AM

Ok!

So I followed your simple (and fairly intuitive) instructions :

 (http://i722.photobucket.com/albums/ww225/kalkhr/riser002cut2.jpg)

 (http://i722.photobucket.com/albums/ww225/kalkhr/riser003.jpg)

The thing that worries me is cutting into the upper limb (circled in purple).

Will this weaken it considerably?

How far in should I cut? (I can imagine that the answer is : "as far as you need to", but I want to know how far is safe)

Thanks!

Title: Re: First Lam Bow with pictures, Need Advice.
Post by: bjansen on April 03, 2009, 09:36:00 AM

Wow..that is a heavy one...it looks great..

The riser is little short but that will work just fine.  

After you mark that line above your hand just draw out where your cut will be on both sides of the handle.  Make sure you start the cut at least 1/2 from the end of the fade and work your way in.  I would suggest cutting 1/3 into width of your riser for the shelf.  

Cuttin into that upper glass (your purple section)will be fine, as long as you keep your cut in the riser...and again...i would stay about 1/2 away from the end of the fade... (obvioulsy cutting into the limbs would weaken that limb).  

    (http://i492.photobucket.com/albums/rr287/bjjanse/Bowerpics019.jpg)

After I do the cut on the bandsaw, I will usually round the front of the shelf.  Then work the shelf joint with a rattail file to smooth e/t out.

Title: Re: First Lam Bow with pictures, Need Advice.
Post by: Trux Turning on April 03, 2009, 10:39:00 AM

You can also find the center of the riser- fade to fade and then measure up 1 to 1.25 inches for the shelf. If you haven't already done so now is the time to see which limb is stronger and make that one your bottom limb.

Title: Re: First Lam Bow with pictures, Need Advice.
Post by: Matt. on April 03, 2009, 02:52:00 PM

Thanks guys!

bjansen: thanks, I think I get what you mean :

 (http://i722.photobucket.com/albums/ww225/kalkhr/riser2003.jpg)

Trux Turning: It worked out to 1.75 inches. 1.5 inches is a little too tight. I guess I'll know to make my riser longer next time!

Title: Re: First Lam Bow with pictures, Need Advice.
Post by: bjansen on April 03, 2009, 03:03:00 PM

Yes indeed... your plan looks good to me...you dont have to to all the way to that 1/2" mark though...that is just a bare minimum i would say....here is a link to show you some shelf designs...i typically use ridged or radiused.  good luck

 http://www.stickbow.com/FEATURES/BOWBUILDING/shelf.CFM

Title: Re: First Lam Bow with pictures, Need Advice.
Post by: Matt. on April 04, 2009, 09:55:00 PM

I finished it today. I decided to go with a radiused shelf. Which type do you prefer?

I will post up the pictures tomorrow.

She might a little on the heavy side for me, but she shoots fast!

Title: Re: First Lam Bow with pictures, Need Advice.
Post by: ChuckC on April 05, 2009, 08:23:00 PM

On a lay up w fiberglass, I mark the center line of the bow (top to bottom) and the shelf goes about 1.25 inches above center line.  Note... if I radius the shelf  (I always do) then the high point of the shelf is at that line.  Better check your photo size.  may be too big.
ChuckC

Title: Re: First Lam Bow with pictures, Need Advice.
Post by: kennym on April 05, 2009, 08:27:00 PM

Brad, that is a killer link!! I do the ridge and bevel the edge,never tried takin that much off the front and back corners tho.

Title: Re: First Lam Bow with pictures, Need Advice.
Post by: Matt. on April 05, 2009, 10:30:00 PM

Here's the result :

 (http://i722.photobucket.com/albums/ww225/kalkhr/handle001.jpg)

 (http://i722.photobucket.com/albums/ww225/kalkhr/handle005.jpg)

thanks for your help.

Title: Re: First Lam Bow with pictures, Need Advice.
Post by: Matt. on April 05, 2009, 10:31:00 PM

I tried resizing the pictures, I guess it didn't work with the second image... sorry

Title: Re: First Lam Bow with pictures, Need Advice.
Post by: bjansen on April 06, 2009, 08:19:00 AM

Matt...that looks great!  I bet that really smokes an arrow at 102#!!!!!