A continuing problem

[DC]

I've had this or at least a similar problem with a few bows so maybe you guys can help. I got this bow out to 40#@14" on the short long string. It was looking good and I was starting to think about bracing it. I decided to exercise it some so I pulled it a few times to 14", stopped and now it was 38#@14". I compared it with my tracing and it had around an inch of set. I thought I would take another look on the tree. I pulled it to 40# at 16", next pull was 17". I thought I would brace it so I put on temp nocks and an old string. Braced it and now I have a bow with a bit of hinge that pulls about 35#@26". It was like it just collapsed. I don't think the hinge can account for it all. Like I said I've had a similar thing happen with previous bows but I somehow saved them. This was like four pulls and it lost 10#. Any idea what went wrong? This one was doubly disappointing because it was part of my small supply of Plum.

[burchett.donald]

 Did some of your reflex pull out?

[SLIMBOB]

My first thought is wet wood. This is not your first rodeo so...must be something else.

[wizardgoat]

Quite a bit of reflex Don, those limbs have to travel pretty far to get braced, one small weak spot I can see being amplified with a design like that. You could shorten it, deal with the hinge and see where your at?

[DC]

Did some of your reflex pull out?

It did when the weight started going away but it was almost no set until then.

My first thought is wet wood. This is not your first rodeo so...must be something else.

It's had a year and two heavy heat treats so I don't think so.

Quite a bit of reflex Don, those limbs have to travel pretty far to get braced, one small weak spot I can see being amplified with a design like that. You could shorten it, deal with the hinge and see where your at?

Yeah it's kind of a stupid amount of reflex. I've used that caul before and never got that much reflex. I wonder if Plum holds it better than some others. At least until it doesn't.
Is there a possibility that having the limbs too thin and too wide would make tillering a little more touchy?

It's still got a lot of reflex so I could lose about eight inches of bow. It would be about 58" and have an inch or so of reflex. I'll do that. maybe six inches first. If the recurves are pretty much straight up like this and you pike it, basically just cutting of the recurves, does it have the same effect as taking the same amount of length off a straight bow?
Sorry for the blurry picture

[DC]

There's a good chance I just messed up, my minds kinda been on horn bows the last week or so

[burchett.donald]

Don,
         Looking at the updated picture it looks like just the reflexed outers pulled out...Don't see any set in the inner limbs...

[sleek]

Rub a quick finish like oil, into the belly and look for chrysals. You may have simply found the elastic limits of that wood.

[Badger]

  Simple answer is you were asking more than the bow had to give. Once the reflex starts taking set all that extra reflex becomes counter productive even if you finish with a bow that has a decent amount of reflex. The bow will have more hysteresis. What was the target weight of the bow? Especially on that type of design not pulling full target weight from the start can set you up for a sudden collapse.

[Swampman]

DC, I had this same thing happen with a black locust bow.  I didn't induce as much reflex as you did but I did heat treat in about 4 inches.  Everything was looking great and even and I was exercising the bow and all of a sudden I had a hinge form in one limb.

Yesterday I tried to salvage the bow by significantly reducing the weight and not touching the hinge.  There ended up being significant chrysals.  Looking back, I think I did not draw the bow to target weight early enough.  I should note that I had and still have an even taper throughout the limb with the hinge. 

I am glad you posted this because I have been trying to figure out how this happened on mine too.  I thought you may like to know you aren't the only one that had a sudden collapse recently.

[DC]

No sign of chrysals so that's a plus. 40#. I always pull to draw weight unless I'm sorting out a problem. This "all of a sudden" seems to be associated with RD's. And ,yes, I agree that this much reflex is excessive. I should have heated some out when I first steamed it in. I'm just so used to reflex pulling out that I got a little greedy. I've got two more pieces of Plum. I'll be more careful with them.

[Badger]

  I have the same thing happen on RD's more often than I like to admit. The string angles change pretty radically as the limb starts coming around. Best thing is to leave those outers just barely working until they have full come around to where you can see them with max leverage against them

[DC]

I've been using a longer long string for the initial tillering so that it does pull on the outers a bit. It seems to help some. I shorten the string as more and more of the string lifts off. Maybe the key to solving my problem lies in that area. Or like you say don't tiller anywhere the string is touching.

[DC]

If I'm going to pike and correct the tiller on this is there a preferred order. Would it be better to correct the tiller first and then pike it or vice versa?

[bradsmith2010]

DC, thank you for posting this,, very informative,,