I Never Break Bows.

[Dictionary]

I'm too cool for that 




I was making A maple 54 inch d bow with side nocks. Was drawing 40 lb at 17 inches. Wish i had taken pics of the tiller. I'm still a serious newbie at the game anyways so tillering a dbow was a bit new to me but felt a bit easier since i didn't have to worry about the fades. after drawing 17 inches, tiller looked good so i took some more passes with a rasp on each limb. Pulled it to about 40 lb at 18 or 19 inches on the scale(Plywood with a slit on top for the string). Then i put it on a tillering stick and pulled string down to 19 inches and Pop. It didn't crack or warn me of anything. It was like a peice of deadwood used for kindling snapping on you.


I've been looking over it.

Possiblities:

I had tried to get a twist out of the limb and scorched it a little bit. The limb that cracked was the one i tried heating(using propane gas grill. So maybe moisture content was too low? Most of the bows i've broken haven't snapped like this one so this is the most likely possiblity at the moment.

Wood used: Was a type of maple, but still not sure what kind. It grows fairly straight here but is usally a bit knotty.(This peice had a couple of knots)

There were no hinges. It seemed like an even bend, but its possible that the tiller was fooling my eyes.

It broke a few inches above a knot. I don't think the knot had effect on the break though, other than making it a little more difficult to tiller.

Better luck next time i guess.  Next time i'll go for 35#@25 or 26inches. Bow twenty something thats broken  . Good for firewood

I know pics suck but any input that could help for the next bow attempt would be appreciated

[DRon knife]

You wanna stop breaking bows build them with hickory or back them with hickory,as for your broken bow,It sounds like you had plenty of reasons for something to go wrong,just avoid those things next time..lol,Ron

[MWirwicki]

Your break was virtually straight across the limb.  This usually indicated to us that the wood was dryrotted.  I had a bad run of hickory backings which broke in the same manner (straight across).  Under a magnifying glass, the wood looked like styrofoam. 

[JW_Halverson]

Welcome to the largest single-factor demographic on this website.  There's two types of bowyers; those that have broken a bow, and those that have't gotten far with their first bow.

(Ultimately there are three types of people in the world; those that are good with math and those that aren't. )

[mullet]

Uh, you pulled it too far. Maple, unbacked, 54", pulled 19", and tillering stick or runoffs in the wood could be a contributing factor.  I'd have backed it.

[Dictionary]

Welcome to the largest single-factor demographic on this website.  There's two types of bowyers; those that have broken a bow, and those that have't gotten far with their first bow.

(Ultimately there are three types of people in the world; those that are good with math and those that aren't. )

That couldn't have been said any better.


MWirwicki- i didn't consider that at all. I really didn't notice any type of damage to the wood beforehand relating to insect damage or what have you.

[Dan Perry]

I know, at first it is frustrating when a bow breaks, but their is always a reason and an important lesson. I was in the shop today moving bows in my bone pile around, and couldn't help holding them and remembering the lessons they taught. In time you will find yourself testing an idea, and stressing a bow until it breaks to see what happens.

I am just happy to see you building bows and trying new designs. Good luck with your new project.

Dan Perry

[Pat B]

Welcome Dan. Good to see you here again.   

 Dictionary, what species of maple were you using. Is that a tree stave or a board? Looks like a tension failure the way it broke straight across the back. 

[Dictionary]

Mullett-i was sure i could pull a 54 inch bow to 25 inches. You don't think maple can withstand that tension at 54 inches?


Pat here is a picture i took of the maple im using if it helps at all.I'm located in North GA near stone mountain and this maple grows fairly straight in here but often the saplings are quite knotty.

[mullet]

Dan;

I think you should have been able to pull it that far,,but; How much weight did you have stacked on it? I think there could have been some factors stacking the deck against you.

 I don't know how long you had it at draw on the tillering tree, but I've had them blow if they have been there and had a knot that was stressed. Sometimes it doesn't take much. Also you said you took some pass's with the rasp and strung it up. Did you clean the rasp marks and smooth it before pulling it to draw? I've had them break because of that also. Before I put one on the tiller tree now I sand all the bad rasp and file marks out.
 But, JMO I think it was pulled a little too far for just a tad too long on the tree when that one section of wood couldn't handle that much weight. Like Pat said," a tension break".
  It happens, I do it all the time with Yew. That's why I'm going so slow on the Build-along I'm doing.

 

[Dictionary]

Dan;

I think you should have been able to pull it that far,,but; How much weight did you have stacked on it? I think there could have been some factors stacking the deck against you.

 I don't know how long you had it at draw on the tillering tree, but I've had them blow if they have been there and had a knot that was stressed. Sometimes it doesn't take much. Also you said you took some pass's with the rasp and strung it up. Did you clean the rasp marks and smooth it before pulling it to draw? I've had them break because of that also. Before I put one on the tiller tree now I sand all the bad rasp and file marks out.
 But, JMO I think it was pulled a little too far for just a tad too long on the tree when that one section of wood couldn't handle that much weight. Like Pat said," a tension break".
  It happens, I do it all the time with Yew. That's why I'm going so slow on the Build-along I'm doing.

Well i didn't take in account any of the things you mentioned while i was making it. I was only aiming for 40 lbs. It was pulling 40-43 pounds at 18 or 19 inches on the scale, then i put it on a tillering stick and pulled down to 19 inches and it snapped on me.  I've never thought it was important to scrape clean the rasp marks either.....

Thanks for your input. I'll remember it for the next bow i build.

[mullet]

Dan,
Also, before you just pull it down on the stick, work it by pulling it repeatbly to warm the wood up. Even pulling a full tillered selfbow that was just strung is asking for it to break.

[Dictionary]

Instead of making a new thread, i also wanted to reference something related to dbows which is what i was attempting to make.

In the primitivearcher article "Simple D Bow" this is said referring to why a dbow is a good design, i quote:

"(6) Are narrow Again a by-product of using small diameter trees or branches but once again providing other benefits, like being easier to hold without having to do much shaping on the handle again saving effort. More importantly a narrow handle means a narrow arrow pass, which means the bow will shoot a large variety of spined arrows without having to deal with the dreaded archers paradox. Important when good arrow material of a single given spine is hard to obtain."

I thought the opposite of this was true and that a wide limbed bow with a narrowed handle section is more versatile to shoot arrows of various spines. A 1 1/2 inch wide handle on d bow doesn't sound like it would be more center shot than a narrow handle section on wide limbed bow. I figured this would be important since i'm in no way skilled at making arrows yet and cannot determine a proper spine for a certain bow. Could someone explain this to me?

[okie64]

The closer that a bow is to centershot the more forgiving it will be as far as arrow spine whether it be a d-bow or a flatbow. When most people make d-bows they still narrow the handle up a little bit for this reason and to make it feel more comfortable in the hand. Sometimes I narrow the handle on d-bows and sometimes I dont, it really just depends on how wide of a bow I am making. If I'm making a bow with 1-1/4" limbs or wider then I narrow the handle down to about an inch or so. I dont know if I explined that very good or not.

[Dictionary]

Yes okie i understand a bow that is more center shot can shoot more varied arrow spines but i'm trying to understand how could be more center shot than a narrow handled non bendy bow. I would think that the dbow with a 1-1/4 inch wide handle is less center shot than a narrow handled bow with a handle about 7/8 of an inch to an inch wide. I would think this is more center shot and a bend in the handle bow is less center shot. This is just to prove that the quote i posted from the article isn't really credible because bend in the handle bows have to have their widest part at the handle making it less center shot.

Am i correct?