First steps...

[Kegan]

Well, I posted about trying a hinge take down a few monthes ago... finally found a bow to try it out on! Actually, I built this one specifically to test it. I went quick on this, it was one of my first hot-box cured staves but it survived the abuse too. I tried a store bought hinge first, but it pulled apart just trying to brace the thing- so I used a home made one. It only pulls 60#, but the hinge is holding up fine. Actually, I snapped a screw off in one of the pre drilled holes and had to toe (tow?) the screw at an angle. The hinge did stretch some, hence the gap, but now it's all worked in. Despite all that trouble, it's holding. I'm planning on killing this bow for a punishment test on the hinge and then reuse it on another bow. I'm going to do a test for strength tonight (left it together to show my friend Art), but I'm going to pike it down to about 70+# just to see if the hinge survives (hopefully the limbs hold up long enough to find out ). Wish me luck on that. The screws stick out a bit too much, so a velcro leather grip should be needed. Likewise, the limb shape needs to be different because it doesn't fold right.

It's a real mess, but it's a step closer to my Super Bow . Next step, hinge to deflex grip for a R/D longbow...

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[n2huntn]

Cant wait to see whats next!!
Jeff

[The Burnt Hill Archer]

interesting, ive been thinkiing about doing this for a while. it'll be cool to see how far you can stress it...

[Pat B]

Pretty cool, Kegan.
  You could add a horn spacer between the halves to get a flatter fit.

[DanaM]

Only 60#

Pretty cool Kegan I don't think with a hinge like that you will get a perfect fit with no gap unless you use a spacer as Pat suggested..

[KenH]

Nice idea Kegan.  What about, eventually inletting the hinge into the back like you would a door hinge, rather than surface mounting it was you have there?

[denny]

Keep an eye on the 3rd screw, when they starts to come loose, it will be the one and the rest will follow. And it hurts when the upper limb swats you in the head ,especially a 60lb bow at full draw. I won't say more, I got lotsa scares . I have a friend who makes a hinge for take downs and it is recessed in the limb.The idea of the hinge is to take apart and he has a slide bolt that is fixed and allows you to take the bow apart. He uses a slip handle wrap for the handle. Good Luck and be careful. Denny

[Kegan]

Great suggestions guys! I was thinking that on a final bow, an ipe spacer would be alot better than letting the hickory smoosh against itself (no horn). Likewise, Ken that's a great idea! As I'll get into later, I was also thinking about adding some sinew to the inner limbs, so that and a little filing/fitting might recess the hinge comfortably- I like it !

Last night I went and piked it down from 68" ntn to 64", getting the weight back up to 70#. The hinge stretched some more, but suprisingly the bow held up (actually, it's now a straight-shooting rocket launcher ). This stretched the hinge a little more, which began wobbling side to side when I drew the bow, so I stuck in a little piece of oak, slanted so the one side it tended towards wouldn't begin to "kink" all the time. As you can see from it folded (which I forgot in the other ones- this is before the piking), it doesn't sit together pefectly.

Right now I seems that the hinge is stretching out almost as much as it can (it's two folded pieces, they can only go so far unless they want to just give up and break), so when I transfer this hinge to the next bow I'll simply put the hinge on tight, tow (toe?) the screws, and then adjust a spacer if there's any more stretching.

From the full draw pictures you can see that most of the bend is in the inner limbs, which got me thinking about sinew. I'd prefer to do the limbs as a normal flatbow with long, sweeping reflex, and then use the hinge to make a deflexed riser to create a R/D bow without the tillering/bending head aches. Given that this bow is a bit shorter than normal and yet still accurate (and quick), I'm seriously consiering perhaps a second bow at this slightly shorter length with sinew (to reduce set and add mas near the grip). I built a second hinge yesterday and may well try both of these options. I'll be using this current bow to stretch the second hinge also, rather than having to adjust on the new bow. On a side note, this little experiment bow is helping me see what attriubtes make for a more stable bow. Even with all the flaws, this bow shoots the pants off of "Sweet Imperfections" at 20 yards. More notes for the notebook then!

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[Del the cat]

Great, I do love to see experimentation!
It seems like a sound idea, the screws will be the weak point rather than the hinge I'd have thought.
Maybe wear a crash hat?
Del

[Kegan]

Great, I do love to see experimentation!
It seems like a sound idea, the screws will be the weak point rather than the hinge I'd have thought.
Maybe wear a crash hat?
Del

I listen for cracking creaking, and feel for movement every time I draw. For final, serious bows my father has some thick stainless steel screws. Right now I'm using some thicker ones that aren't as brittle (more apt to bend, but won't snap off) rather than normal ones. I refuse to use normal ones because of their tendency to snap off so readily

[M-P]

In the not too distant past here was a commercial product called "The bow hinge"   I bought and installed one.  Actually I installed it three times.   The screws were definitely the weak link.  The screws supplied with the product were just dry wall screws and they sheared off while I was still tillering the stave.   I purchased the largest wood screws that would fit the holes and installed the hinge again.  That got me a bow that shot hundreds, or perhaps even thousands of arrows, but eventually I could see the screws on one side starting to deform.  I then drilled one of the screw holes larger ( for larger size and to remove the counter sinking) and then applied a stainless steel pin.  I also bedded the hinge in epoxy before applying the remaining screws. Years later the hinge is holding up, but the limbs are starting raise some splinters.  In spite of the problems this has been one of my better bows, but nothing lasts forever.
Anyway, I would suggest that you replace one of the screws with a pin and consider bedding the hinge in epoxy to give the strongest attachment possible.
Ron

[KenH]

Instead of screws to hold the hinges, I would use through-drilled holes with nuts and bolts.  Less chance of anything tearing loose in catastrophic failure mode.   Use washers on the non-hinge side to spread the strain even more.

[George Tsoukalas]

Would  a sinew wrap around both sides of the hinge work to stabilize it? Jawge

[Kegan]

Thanks for all the input everyone . Right now I'm looking at a stave that has some knots in the top limb that would make double-limb-curve R/D bow nearly impossible. So that makes it a good candidate for a reverse gull wing R/D bow in my opinion. For this one I'll use the heavy steel screws my father has and try and use the hinge for deflex. Should have pictures some time this week/weekend.