Eric, building a bow that stands straight after being shot-in isn't as simple as heating in the right amount of reflex. It often helps, but there are a bunch of other factors too that need to work together to make it happen. You can reflex the livin' snot out of a stave, but if too many other factors work against it, it may follow the string in spite of your efforts. Some of these other factors include, but are not limited to...
Moisture content of the wood: If it's not adequately dried, it's gonna take unnecessary set... even if everything else is done well. Here I'd like to add proper care of and storage of wood after being cut. Whitewood especially, can degrade quickly after being felled if not properly cared for, which can lead to unavoidable set.
Design specifics: If it's too narrow, thick, or working limbs are too short and such relative to draw weight, draw length, abilities of the wood, etc... it's going to take additional set.
Inherent quality of the individual PIECE of wood: If, for instance, you have two pieces of osage, and make identical bows with them, with the only difference being ratio of early to late growth in the annual rings, the bow with the higher percentage of more dense, clearly defined late growth is going to take less set than one with more early growth saturation and less dense late wood.
Tillering: If each inch of limb isn't contributing equally to the work being done... if some is working harder than others, the overworked areas will be under more compression and tension which can cause set. Also in regards to tillering, if a bow reveals an area that is too stiff or too weak during tillering and you don't address it, but draw the bow farther, you're causing unnecessary set in the areas that are forced to work too hard. ....So it stands to reason, the more your eye for tillering develops with experience, the sooner you'll recognize problem areas, get them corrected, and the less set your bows will take in the end.
Wood species vary in their ability to deal with tension and compression stresses, but if designed accordingly, many of them can be made to take little if any set in a finished bow. The less they're able to deal with this stress, the wider, thinner, and longer they have to be to accomodate certain design, draw length, and draw weight requisites.
That's why I prefer osage and yew. Generally, I like short, narrow, deeply radiused bows, of 60+ pounds, and osage and yew can deliver the goods if I do my part.
I don't mind my bows taking a little bit of set... that way I know I'm not overbuilding them.
Keep in mind during these discussions that 'set' and 'string follow' aren't synonomous. You can induce 4" of reflex into a stave and if it stands perfectly straight after shooting-in, it took 4" of set, but has no string follow.... so you still could have done things differently, if you wanted, to minimize the amount of set it took.
Our ability to coordinate and balance all the factors involved in making wooden bows that are neither overbuilt or overstressed is dependant on, and develops with, the skills and understanding gleaned through attentive, inquisitive, experience.
Topic: asymmetrical limb tiller check (Read 943 times)
