How Stable Are Your Bows?

[missilemaster]

I wonder how much affect temperately setting the bow down after you unstring it plays a part. We all do it, after shooting, we set it against a tree vertically for a bit Then come back for it and store it horizontal. But when its leaning against the tree unstrung, its putting more weight on the lower limb and not allow it to gradually come back straight again, however slight it might be. I wonder if over time, that can "soften" the lower limb.

[Dances with squirrels]

I doubt that's it. I use a metal hook and the tiller doesn't change.

Speaking of hook placement though, I'll bet that a cause of shifting tiller in some instances is how some folks tiller their bows by pulling them differently on the tree than they do by hand. For instance, pulling at the center of the handle on the tree, then shooting them with the string hand fulcrum 1 1/2" or so higher. Shifting tiller as a result may just be the bow adapting its new training regimen.

[blackhawk]

Guess ill add my 2 cents...

I think using seasoned wood helps a lot in this regard..it may not prevent it every time,but i do think it greatly reduces the chances of it happening as long as the bow has been properly tillered and cared for...theres more shrinkage of wood cells over time even if it has been quick dried soon after being off the stump...ive had it happen twice to me out of all the bows ive built...both were hickory properly tillered,and properly cared for, and stored in a strict monitored setting,but both were under a year old off the stump...ive never ever had any problems with seasoned osage...and i believe the ole timers touted only using seasoned stock because of this issue (or one of the reasons why)

so my answer and solution is to use good seasoned osage!!!!  osage will always usually hold what ever tiller shape ya give it even if its a sh!++y tiller job...

[George Tsoukalas]

Yes, indeed, on the importance of using seasoned wood.

In my early days when I was bitten by the bow building bug, I would invariably run out of seasoned wood. So I would rush a bow and end up with lot of set.

Then I got a moisture meter and started using it and noted that my bows took much less set.

Then, I'd take a bow off the rope and pulley after tillering from center and find the lower limb taking more set.

Then, I discovered digital photography. Nothing approximates how I pull a bow so I have a family member photograph the bow at full draw to check tiller. I like the lower limb stiffer even or stiffer by 1/4" at full draw.

I don't care too much how it looks at brace. Full draw is important. 

One of these days, I'll photograph a bow at full draw after shooting it for a few years.

Jawge

[BowEd]

Interesting worthwhile subject dragonman.Every future or even present bowmaker could benefit from reading this or someone liking the use of primitive type bows.Only those who shoot a lot can see this.Seems like until someone makes or shoots a bow with a lot of refllex the use of a stringer is'nt used.Otherwise the usually push pull method.I never did like the step through method.Maybe I don't do it right.I know I've seen bows strung up not with the exact tiller I put on them then pump on them a few times and they correct themselves.Which still leads me to think bracing a bow evenly is a wise thing to do.The storing vertically or horizontally is up for debate yet.A stable enviornment is needed.After shooting I always try to lay the bow down horizontally just because of the thought of letting the limbs come back unobstructed.I do tiller mine always an inch past my draw just for safety reasons.All in all I don't see the widening of the lower fade over time happen much with my bows as of yet.I'll have to keep a shooting but know a lot of my bows do have thousands of shots through them.1/8" positive tiller is the max for me and my way of shooting,gripping,etc. with the shelve approximately 1.5" above center of bow with even length limbs.

[BowEd]

Ohh forgot to mention the positive tiller I put on a bow is evenly the whole length of the limb too.Seen people just check by the fade when braced and that's it.

[E. Jensen]

I'm not so sure about the water and gravity part of things.  Remember that the water defied gravity in the first place through passive capillary action.  Trees don't have water pumps.  But below ~30% moisture content, there is no loose water in the cells anyways, it is all bound to the cell walls.  AND the cells are clogged with extractives in the heartwood, and the vessels/pores in many hardwoods (including osage).

I've read that the moisture content in the air can differ near the floor/ceiling.  That seems more likely if different MC is involved.  But I'm not a moisturologist.

[Dances with squirrels]

I've heard of guys sliding the larger string loop up the bottom limb instead of the top, stringing the bow with the bottom limb toward the sky, presumably, to avoid making the bottom limb weaker from stringing with the push/pull method. But I'm not sure I'd buy that as a cause of shifting tiller... since we're only straining the bow a wee bit to get it braced, and after a tug or two, it goes right back where it should be.

[sleek]

Would a low reverse brace help with this? Like a second nock cut into the upper limb to slide the string doen and catch, then pop the bow into reverse brace?

[Badger]

I'm not so sure about the water and gravity part of things.  Remember that the water defied gravity in the first place through passive capillary action.  Trees don't have water pumps.  But below ~30% moisture content, there is no loose water in the cells anyways, it is all bound to the cell walls.  AND the cells are clogged with extractives in the heartwood, and the vessels/pores in many hardwoods (including osage).

I've read that the moisture content in the air can differ near the floor/ceiling.  That seems more likely if different MC is involved.  But I'm not a moisturologist.

  If you have maybe 75 bows stuffed into a drum, you just don't have as much air circulation as you would with the bows sticking out of the drum. I don't see much of a mystery here. Some of the staves were still drying. The moisture level will be higher in the lower potions of the drum.

[E. Jensen]

The top of the drum is open? 

[Badger]

The top of the drum is open?

  Yes, so the bottom half is in a cardboard or plastic drum and the top half is in open air.

[E. Jensen]

Of course the bottom MC will be higher, and I don't think because of gravity.

[PatM]

Water vapor rises, it doesn't sink to ground level.   So the humidity in the bottom of the barrel would be lower in the surrounding air.

[Badger]

  Pat, when you have air moving across wood it dries faster. If you have a bucket full of bows there is not much air movement. I am well past the theory stage on this. I took them out of the bucket and problem was solved once they acclimated.