Question about selfbow?

[wapitishooter]

What can you do, or can you prevent your bow from limb set? If preventable whats the secret?

[KenH]

As long as it's a self bow -- single stick of wood with maybe a handle added in the middle -- it will take a set over time.  Just the nature of the beast.  Don't leave it strung a minute more than necessary.  Some people swear by manually deflexing the bow when you unstring, not just letting it go back to the unstrung shape naturally. 

[Forwardhandle]

You can heat treat a reflexed profile in your limbs to compensate for set if you have a draw of 28" or below you will lose Aprox half of the reflex treated in with good tiller ! Even minor reflex forward of the handle adds cast !

[Pat B]

Set is the nature of the beast with self bows. There are things you can do to reduce the amount of set and string follow.
The wood use will determine what to do and what not to do. Woods like osage don't need much except good tillering but adding reflex and heat treating as you reflex can be an improvement. Hickory, maple, elm, locust, oak and other whitewoods need a good, deep heat treating with a little reflex added at the time. 3" to 4" of reflex is plenty and if you tiller properly you should end up with shot in bow with 1" of reflex or a flat limb.
Never over stress the wood as you tiller your bow but do exercise the limbs after every wood removal. Never draw beyond your ultimate draw weight and never draw a selfbow beyond it's intended draw length. A bow fully drawn is 9/10th broken!
You could still develop set over years of use but if you are familiar with your bow's cast it can still be as accurate as it was for it's first shot.
 Post pics and ask questions while you build your bow and we'll all give you a hand.

[Bowjunkie]

What Pat said is true, and I would add, it starts with tree selection... type, growing conditions, and quality. Then from where in the tree the stave is taken. Then proper and prompt field care, storage, drying. Add in a design well-suited to the wood's abilities, and to our needs of the bow, the experience and knowledge needed to properly tiller and truly balance the limbs, and you're off to a decent start. Limb imbalance alone causes set in selfbows.

Sometimes we can't, or choose not to, control all such things, and that's just the reality of it, but it does raise the risk of set happening, in what we tend to consider, 'beyond our control'. In other words, you can get a hickory stave from someone that left it outside under a tarp(happened to me), and it may look like a pristine piece of bow wood, only to take so much set as to be completely worthless, and far beyond any tillering, design, heat treating, etc efforts.

[neuse]

If set is caused by the wood cell structure being crushed by compression.

Then why does a well seasoned stave take set?
Are the cells still being crushed, after seasoning?

[Pat B]

It's a given that set happens. The degree of set depends on how well you learn to tiller properly, how well you can prevent over stressing the wood.

[Eric Krewson]

I have handled hundreds of osage staves, every now and then you run across a piece that won't ever take any set and may hold reflex. The vast majority will take set over time, even if you reflex the bow blank with heat prior to making a bow.

[John Scifres]

My lowest set bows have the following:

1. Good, dry osage.

2. Wide, rectangular cross-section limbs.  Full width carried at least halfway through the limbs.

3. Very low stress while still in the tillering stage.  In other words, get it as close to final bow dimensions as possible before seriously stressing it.

4.  Sufficient bow length for the draw length.

If you add sinew correctly, you can do a lot more but it carries a weight penalty.  But in the right design, sinew will make a snappier bow.  But, long bows and sinew don't match IMO.