Edge or Flat lams ?

[Forwardhandle]

I got another sled from Kenny yesterday and was planing on trying grinding my own lams , I have some supper clean flat sawn maple boards in the shop , has any body notice any performance difference between flat or edge grain lams , I know there is different theory's on the subject but its always nice to get the hands on opinion ?

[KenH]

Between glass, the cut of lams should make no discernable difference, since the glass provides over 80% of the strength of a wood-glass bow.

[C. Johnson]

Between glass, the cut of lams should make no discernable difference, since the glass provides over 80% of the strength of a wood-glass bow.

I agree with this 100%.

You can't go wrong using hard maple as a core wood.

[Crooked Stic]

I think it depends if it is a recurve or longbow. It will less noticeable on longbows as far as a possible grain run out. Hard to beat elm edge grain for core wood.

[Roy from Pa]

Hard to beat elm edge grain for core wood.

X's 2

[EwokArcher]

Red elm is my favorite wood to work with. Love the smell. I also tend to agree with the edge grain comments. Take a piece of edge grain it tends to bend more symmetrically vs flat grain. I also agree that its pretty much negligible but I could see how you might consider this as a factor with recurves >long bows.

[Forwardhandle]

All Im making at this point as far as glass bows are long bows but Im wondering if I use Stable core in the mix if that wouldnt negate any of the down side to flat grain, sense I have a lot of flat sawn lumber around ?

[Roy from Pa]

Flat sawn will be fine.
Heck it's only a glass bow.
 

But 1/4 sawn rocks.

Prolly a good 10 fps more speed.

[Forwardhandle]

10 FPS is huge 😃

[kennym]

Flat sawn will be fine.
Heck it's only a glass bow.
 

But 1/4 sawn rocks.

Prolly a good 10 fps more speed.

Another test needed. So many tests, so little time....

[Forwardhandle]

A test would be good I can understand the stability thing for recurves but the speed thing I have a hard time understanding sense the core is in the neutral plain & is the same mass. But I don't understand a lot of things 

[Roy from Pa]

But I don't understand a lot of things 

Don't feel bad, you are not alone:)

[Crooked Stic]

Edge grain will be a bit stiffer. I think the stable core would be  plus with flat grain in a curve.

[Forwardhandle]

Thanks Mike the more I read about that stablecore the more Im liking it ,when I get around to it Im going to try it with these flat grain lams with the economy of making my own I can try different core materials.

[Pat B]

When I got my Treadway(1999) bow Mike and I discussed core woods and grain orientation. I wanted osage but Mike suggested elm, flat grain for the back and edge grain for the belly. I liked the flat grain on the back because of the somewhat camo affect. Mike's thinking was the edge grain would be better on the belly side because of it's resistance. His thoughts on type of wood was that elm is a little lighter physically thus making a slightly faster bow, but probably not all that noticeable. I went along with Mike's suggestions and am still happy with our decision almost 20 years later.

[Flem]

According to the USDA book on wood as an engineering material, flat sawn with no grain runout would be the strongest in tension and quarter sawn with no grain runout would be the strongest in compression. The more runout you have on a lam, the less any of that matters. If you have nice straight flat grained wood, you could try using less glass on the back and let the wood do more work. Self bows don't do well with grain runout, which should tell us something about strength and elasticity. I like flat sawn.

[Mad Max]

James Parker told me a 1/4 sawn Osage sinew backed is awesome

[Forwardhandle]

James Parker also uses flat sawn core lams in his composite bows !

[Pat B]

When you are using FG back and belly the compression and tension strengths are a mute point. For self bows flat grain is the best but with backed bows I think edge or bias grain are the best. Other composite bows take care of compression and tension strengths.

[Forwardhandle]

Flem made a good point on the run out I have a lot of flat & rift sawn maple around with zero run out but most of the edge grain boards I find have a lot of run out , I'm only using these for glass bows ,all thought maple will make a nice self bow with the right design , but I think it shines as a core wood !