Advise on cable backed plum recurve (pic heavy)

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Hey fellas,

I need advise. Here's my dilemma. This plum sapling recurve is 56ntn. It has a 4" stiff handle and the arrow pass is 1" above center. It has induced deflex in the working limbs. It tillered out to 38# at 24" which is too light for my taste. I figured what the heck, I'll add a 14 strand B-55 cable after seeing how much weight Fiddler gained with one of his nylon cable backings. Beleive it or not, it raised the draw weight to 53# at 24" which is much better .

Problem is, when I steamed in the recurves the string tracked right down the center and it stayed that way through the tillering process. Add a cable, and suddenly they're way out of whack.

The bends lifted some big splinters, so I glued them back down and added rawhide on the belly side and wrapped 'em up real tight.

If my pictures captured it right you can see that the limbs developed some severe twist on the outer 1/3, from the farthest point where the cable is lashed to the limbs and into the recurves. The string still tracks down the middle of the handle regardless of string position, but when I use the double nocks it's pretty close to running off the edge of the curves. If I kick the string off the ends and make it a side nock configuration, it helps the string line up down the center of the recurves better and still remains centered on the handle.

My question is:
Would you guys feel safe shooting it as-is with the side nocks? Or should I be able to heat and twist the outer 1/3 (where there is no cable touching the limb) to get better alignment on the recurves. I've never had one with this much twist so I'm feeling skittish. It shoots as is, but longevity is my concern.

Attached are pics of both the double nock and side nock setup.
Gotta say, the cable made this thing a rocket launcher.. The flattest shooter I've built yet.

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Few more misc. pics

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Double nock setup.

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Side nock alignment.

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Just shot it some more. Helps if I raise the brace so it's juuussst off the limbs. If I leave it double nocked the string really wants to pop off... Side nock setup works though. 50 more arrows and counting and no slips. I definitely wanna correct it if anyone thinks it's worth it.

[joachimM]

I fear this won't be a long-lasting bow, but not because of the string alignment issues.
I've backed four plum and hawthorn sapling recently. Both woods are very good in compression, and backing them can increase the draw weight in a rather spectacular way, like here.
The problem is that the belly of such a bow is edge-grained, and knots or pins come out sideways. Since wood is much, much weaker in compression perpendicular to the grain than parallel to the grain, and since these pins can run along half the width of the belly, you get spots where hinges can develop. Leaving the belly wider in those areas doesn't change the situation. In a normal, heavily crowned sapling design, the back isn't so strong, so the belly isn't stressed a lot. Now if you start adding a strong backing, like you did (and as I've done a few times), you get a stronger back but not a stronger belly. Toasting the belly will even enhance the difference in compression strength of the normal parallel fibers and the perpendicular wood fibres of the pins. Initially, the bow shoots very well, very fast.
Slowly but surely, hinges will start to develop around these sideway pins/knots. This can happen rather suddenly (e.g., as a result of moisture changes, which affect tension/compression ratios). Eventually, the bow breaks at or close to these pins due to compression failures.
Check if the splinters that lifted were close to such belly pins.
I've learnt the hard way that if you back a bow with a strong backing, you need a perfect belly free of lateral pins. Such saplings are rare.

I have the impression that your inner lower limb is already too heavily stressed, and in danger of hinging. 

[blackhawk]

That might not bother and offend some folks....but that doesn't matter...if its bothering you and affects your shooting mentality then fix it. Get the heat out and tweak it over...

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The look doesn't bother me a bit Blackhawk. I was just curious if it was considered acceptable by more experienced bowyers. I can see where Joachim is coming from, cuz it did split right at the pins knots when bending the curves. I'm not really in love with the thing; it was more of a random experiment so if it blows up it blows up, no hard feelings.

No cryals or hinges yet, but I won't keep my hopes too high on it surviving long term. The cable is really tight, hence the 15# gain so I could see it overpowering the belly. Hopefully the cable keeps it from exploding violently towards me.

[simson]

You have several problems here ...
First see f/d, too much bend bottom limb right after fade. You have to fix that first.
Next cable wrapping:  see Mason's book, there is a lot of different ways for doing this. Or visit Dick Baugh on primitive ways site, here is a good tutorial.
Then correct string alignment.

[fiddler49]

Very interesting! So you got the cable tension just from the wrapping. Simon's right about the bottom limb.
You could stiffen the week area by putting a bridge under the cable right above weak spot or wrap a splint above weak spot. cheers fiddler49

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Thanks for the help. I'm going to apply it to my next attempt at something like this. (If there is one). I'm thinking this one might not be worth much effort to save. I just have a gut feeling this knot riddled little sapling is gonna let go.

Simon, great tutorial by Dick Baugh, thank you.

Fiddler, Its all in the wrapping. There are two nocks on each tip, one for the cable and one for the string. The cable is essentially a reverse braced 14 strand string.. It's just long enough to stretch taught over the nocks without placing any reverse tension on the limbs. Then I lashed it to the ends, handle,  and then worked my way out from the handle as far as I could before the tension got too great for me to continue (approx 20" out from the center of the handle).

Pry looks like a crazy  way to make a cable but it seems to work! It was very simple to do and only took about an hour, added 15# and changed the shooting characteristics quite a bit. I think if Ida tried it on a better piece of wood it might have worked. The most noticeable difference after adding the cable was how much early draw weight it gained. Feels real tight right from the get go.

I think I'll try lashing a splint to the weak spot just to see if I can keep it alive. I won't lose a minute of sleep if this thing explodes. It was a fun experiment nonetheless.