I have been thinking about how to help keep the handle from popping off a self bow. I realize if you do the fades right and tiller corectly, this is a non issue but a little overkill can be good. I have concidered drilling 4- 1/8" holes between grip and handle (2 on each end), installing dowels with glue. The dowels would go all the way thru the handle and board. If any torque was introduced into the handle, this might help. What do you think. Don
I just did the same thing to repair a board bow in which the handle was coming off. I didn't drill al the way through though. I thought I had tillered it well and had a long section which did not bend, apparently it was very subtle, but still started to let go.
I don't like drilling holes in a bow.
If your handle sits above the plane of the limbs you shouldn't have to worry about the handle popping off. As long as the handle area doesn't flex at all you will be OK. Pat
Two things will keep you handles on, proper fade angle and Urac-185. Dowels will not hold a handle on in the fades where they usually pop loose.
Here is a fix for a friend's bow that he couldn't keep the handle on. The actual limb running through the handle is only about 1/2" thick. I built up the handle with several laminations of 1/8th thick osage. I also retillered the bow to have the limbs a little stiff out of the fades. No more handle problems for this bow.
(http://img.photobucket.com/albums/v181/ekrewson/bow%20making/bondofixhandle.jpg)
Your handle is popping off because you are putting it in a place that bends. Make sure it doesn't bend and it won't pop off. This is generally achieved by leaving it thicker there.
I have made bendy handle bows with thin lams in the handle. Spread the bending over very thin seperate lams and use Urac, the handle is no different than any other part of a lam bow.
You can also make a handle riser with thick shoe leather that will bend with the bow. Pat
Erik has a good idea, there. I have kept a handle on with dowels, but mine were bigger (1/4")and I drilled them at an angle. I amde them out of jatoba to be plenty strong. I drilled from inboard to outboard, about 20 degrees, kept them out of the fades and in the thickest part of the handle. The handle bent slightly before and less after. I did rework the fades so they had a longer thin portion and were more gradual.
I'm not yet knowledgeable in the art of bow making but I am learning fast. One thing I do know from architecture and furniture making is that dowels do not resist shear well. Another words, when the bow bends, it isn't the bend that is causing them to pop off, it is the shear of the woods trying to slide by each other. For example, take a deck of playing cards and bend them. Notice that the edges stay paralleland you can now see a little bit of every card.
As others have mentioned, probably the best way to do this if you are going to allow bending in the handle is to make the handle out of multiple laminations. What this does is reduce the amount of shear on each glue joint. The ratio is simple:
1 handle lam = 100% shear between bow and handle
4 handle lam = 25% between bow and each lam.
If you have to use the dowels, the best way to do it was the way that Springbuck said, at an angle because this created more dowel surface area at the connection between the bow and handle. You can see what I mean if you cut a dowel in half perpendicularly, and then cut it in half at an angle. The angle cut has more of an oval shape, equaling a larger surface area.
Like I said, I'm no expert and I apolopgize for the physics lesson, but at least it is something to think about.
Rick
If you can keep it from bending it wont break the joint, it you put thin layers on and sand them to a fade it will go a long way to making it work
Clarification, bending is the reason that the handle is popping off, but the actual failure that is caused by the bending is a shear failure.
Also, when talking about the angled dowels, I meant to say larger cross section, not surface area.
Sorry,
Rick
I had the same problen years ago but I started to glue the handle sections on in 1/8th inch strips as well and haven't had one even look like coming off since. All of the wood bows I make them bend coming out of the fades...Glenn...
My experience has been that using thin strips of laminations helps the curves of the handle. If there is a slight reflex or deflex in the bow and you try to glue a straight riser piece on, it will not stay. No matter what!
Using thin laminations solves that problem and is a little easier to do than making a curved riser block IMHO.
jf
No need to be sorry, Rick, that is good info.
The lesson on the shear failure is perfect. I have had trouble with a too-bendy board wanting to pop off a too-stiff handle, and having it pop off from too much bend through the handle. this so why power lams under the backing help so much.
And like many here, I like a thin lam or two between the limb "core" and the handle block.
Your limbs are tillered into the handle.
Dowels will work.I've seen it done by others.