Crooked Bow.

[wood carver 2]

I recently pulled this bow out of the clamps and I was really happy with the way it came out - until I noticed the lower limb. As I looked down the length of the bow, I saw that the lower limb had deflected by about 3/8". It's made from 1/8" hickory on the back and belly and a walnut core that is just under 5/16" and tapers to 1/16". It has a solid walnut riser and a 3/16" white oak power lam and it's 66" long. I haven't yet cut string grooves in the tips because I'm not sure of how I can fix this. The bow can be shortened because I left it long when I cut it out.
 
 
Sorry about the picture quality. I lined up the good tip with the centre line at the riser to show how far the other limb has gone.
Is there a way to fix this, or should I salvage the riser and start again?
Dave.

[JamesV]

Did the bottom limb move over after you cut it out? What kind of form did you use? If it is out 3/8 you can move the centerline over 3/16 on both limbs and it will still cut center on the riser.

[rmorris]

David , how did you put your centerline and template for cutting the limbs on the bow?

[wood carver 2]

JamesV, the limb moved after it was cut out. This was two days ago and it hasn't got any worse. The glue up form is just a wood beam with blocks of wood at the ends. Everything is held in place with a lot of clamps.
Rmorris, I drew the centre line and the layout lines on the back while it was flat, before I glued it all up. Was that a mistake?
I left it clamped for about 30 hours then I cut just outside the lines and rough sanded it.
The bow is 1 1/2" wide so I can narrow it some if it were necessary to get it straight.
Dave.

[rmorris]

If your form is not perfect things can shift or slide sometimes. After I am done with the glue up I use a laser I picked up for Loews for about 25$ and I use it to draw my centerline.

 

 

 

I then made these templates up with holes cut down in the center so I can see that my centerline matches up with my template centerline.

 


 

Hopes this helps and also hope you are able to salvage that bow.

[wood carver 2]

This helps a lot! I feel like an idiot for not thinking befor gluing.    
Dave.

[Glunt]

You can draw the layout lines before glue-up, but you can't use them until you double check it after glue up.  I've only done bows with glass and they generally behave but I did lay & cut one out crooked and fought it all the way after that.  Never did get it totally straight but it shoots fine.

[psychmonky]

That laser is cooler than christmas! Can't believe I didn't think of that! Guess who is going to Lowes today.

Scott

[wood carver 2]

I feel so dumb forgetting that I have a laser    
From now on I'll mark the centre for reference, then, when I remove it from the clamps I'll use the laser to properly mark it.
I'll also use a template to mark the limbs.
I pinned the ends of the limbs with small nails as I got it glued up so there was only a tiny bit of slippage. I thought it wouldn't matter.
Dave.

[wood carver 2]

Well, I redrew the centre line and cut the bow to the new line and got it sanded. It came out straight, so I cut string nocks into the tips and put it on the tree. Looking good! Bending nice and even on the long string, so I braced it at about 3" and put it back on the tree. On the third pull to about 18" it exploded. No warning of any kind. Just BANG! Oh well...
Dave.

[DVSHUNTER]

A shadow from a straoght wall or anything straight works very well and its free.