Maple backed black cherry bow - a question

[Digital Caveman]

How do you know how much set it took if it blew?  Also, the left limb is bending way to much.  I think it blew at mid left limb first.

[Tuomo]

How do you know how much set it took if it blew?  Also, the left limb is bending way to much.  I think it blew at mid left limb first.

That was set in 45" draw. And you are right. But this was just pre-tillered before gluing, not really tillered, because it was not going to be a bow, unfortunately.

[RyanY]

Good to know there’s a margin of safety but this doesn’t tell too much else. Generally we care far more about when a bow breaks down before opposed to when it actually breaks.

[bentstick54]

I’m curious why it was not going to make a bow. What was he initial mistake made?

[Tuomo]

I’m curious why it was not going to make a bow. What was he initial mistake made?

I was making three similar bows at the same time, so I was rushing... So, I chipped off a bit too large piece of the tip of this bow. Of course I could have glued it back but instead of that I wanted to test, how far I could draw it. I didn't need that kind of bow and I couldn't sell it either. I have tested this way many bows and my best has been about 43 inch. This bow broke (!) the record.

So, it broke at 50 inch draw! About 105 pounds. Tough stuff. I specified them to 28 inch draw and it is good to know that they can handle a tiny overdraw. There are always those long hand guys, who want to "try" the bow.

[simk]

Good job! Impressive!!!
May I ask you about the maple backing you used? Was it edge grain or flat sawn (with a continous ring in the back maybe)?
I have used a lot of ash backings edge grain but often thought about using maple (edge grained).
cheers

[Tuomo]

Thanks!

The backing was flat sawn sugar maple, straight from the good blank. So no continuous ring but good enough. I have made a lot of this kind of maple backed bows and I really like them. I think that maple, ash and hickory are the best white wood backing, as it is of course well known fact.

[simk]

looks like these backings are highly underrated. Everybody is using just boo. I like the tought of being able to use my local woods for my builds. thanks Tuomo 

[RyanY]

looks like these backings are highly underrated. Everybody is using just boo. I like the tought of being able to use my local woods for my builds. thanks Tuomo 

If I recall correctly, I think Marc has had good results with maple over other wood backings.

[bownarra]

you will find that in general bamboo will give a bit more snap to a lam bow, that is not to say woods backing are inferior just different. Horses for courses. Of course boo backings follow one ring A lot easier to find good boo then to search through wood stacks for a good board