Does zero set mean "overbuilt" ?

[Del the cat]

All springs take set.
The valve springs in your car engine take set.
It's a matter of degree...
Del

[Jodocus]

I personally think that there should be some set, depending on design and wood and all, usually between 1 and 3 inches. On bows that draw nearly half their lenght, I'm absolutely easy with 2 inches of set. If you build a bow and it takes no set at all, something is wrong. Of course, a stave with 2 inches of relex that ends up straight has of course taken 2 inches of set.

Personally I think (with no prove on my side) that set is overestimatet. It's true that a reflexed bow has more energy stored, but you won't get that out until you unstring it. It certainly does not go into arrow flight. A lower brace will increase arrow energy, since ist's simply force * distance. What will also increase arrow energy is lighter bow limbs. And these will take some set.

I closely observe how a bow picks up set while tillering, because that way I know where the wood is working enough and where it isn't. I try to avoid set in the inner limbs, according to baker's suggestions, but mainly because extra wood in the inner limbs is more acceptable than further out. And yes, you CAN overbuild a bow by making it too wide and thin. Mass formula is excellent to get an idea, I use it on almost every bow I make, especially since I like using different woods.

[WillS]

Draw weight is (I think) a big factor.  If you're tillering a yew bow that draws 45# and pulls 28" having 3" of set is excessive.

If it's a yew bow of 160# and pulling 32" getting 3" is considered pretty good!

[blackhawk]

Personally I think (with no prove on my side) that set is overestimatet. It's true that a reflexed bow has more energy stored, but you won't get that out until you unstring it. It certainly does not go into arrow flight.

Not true.

[steve b.]

If you are talking about making the most efficient bow from a certain piece of wood then, yes, zero set means overbuilt.  To me, the perfect bow is the one that, after exercising it, shows a little "set" (what I call, stringfollow), but within a few minutes or an hour has regained its original shape.  Still, I would rather have the overbuilt bow than the bow with more than an inch of set.

[George Tsoukalas]

Definitions are so important.

Just to clarify. There is a slight difference between set and string follow. Set is how much the limbs change from their original shape while string follow is the degree to which the limbs resemble a strung bow even when unstrung.

If the bowyer induces 3 inches of reflex and then makes a bow with 1 inch of reflex left then the bow has 2 inches of set and no string follow.

I have never built a bow with 0 set. I've built bows that started with a couple inches of reflex and ended even but that's still 2 inches of set.

Jawge

[George Tsoukalas]

Richard, I learned a long time ago not to use the word impossible but I've never seen a  bow with 0 set or built one with 0 set particularly when the definition of set is considered.

Minimizing set is good. Proper wood choice, dry wood  and easy does it tillering will help.

Right now with one bow completed set is not something you should  worry about. Hone your technique and make a couple dozen bows and set won't be an issue.

BTW I measure set by putting the bow with the back against the wall and measuring tip deflection.

Jawge

[Jodocus]

Not true.

You got someting more to convince me? Truth is, I'm just guessing, but I'd love to know, one way or the other.

[PatM]

Obviously you can't use all the energy stored from bracing a reflexed bow but it boosts the early draw weight which adds to the total. As long as drawing it doesn't break down the wood to the point of negating those gains.

[Badger]

  Jacodus, when we measure the power curve on a bow we measure the work we are putting int it. If a bow has more reflex or is straighter than a bow with set it requires more work to pull it back even though the peek draw force may be equal. Some bows drawing 50# for instance may only store about 40 ft pounds of energy while another may stor slightly more than 50#. There is also good evidence that even tiny amounts of set will start to show in energy losses due to histrias ( internal friction).

[Tuomo]

Steve is right about set. I think that set is the biggest problem in wooden bows, in view of performance.

Why wooden bow takes set? Because the belly of the bow can not take the stress of bending. There is few methods for relieving belly stress - for example trapping.

So, if the bow takes no set, it is not overbuilt but it is propably going to break on back. Try to make much trapped (almost triangle) bow, it takes no set but it will break on back. The, try trapping belly, the will take a lot of set.

There is no such thing than overbuilding, except making tips too heavy. Make wide and thin bow, it can bend more than narrow and thick, but it will take proportionally same set. Basically set depends on tension and compression strenght of the wood. For example, think about using g***s just the belly or back of the bow. It does not work.

[Joec123able]

Personally I think (with no prove on my side) that set is overestimatet. It's true that a reflexed bow has more energy stored, but you won't get that out until you unstring it. It certainly does not go into arrow flight.

Not true.

I agree NOT TRUE

[Joec123able]

If you build a bow and it takes no set at all, something is wrong.

How is there any logic in that at all? That is so untrue.

[willie]

as there seems to be temporary kind of set that is noticeable before it becomes permanent set, does anyone try to watch the "return to zero speed" of the limb while tillering? I try to watch the last quarter inch of relaxation by sighting to a line behind the tillering tree

[Badger]

Willie that is a very interesting observation you made. Set is very progressive. Lets say you took the string off the bow and were somehow able to instantly measure set in less than 1/100 of s econd from wehn you took the string off. You might find it has something like 4". Within 1 second it might be to 2"  within 5 seconds it might be to 1" and within 1 minute might be at 1/4". Thats sounds crazy but it illustrates how set affects performance. It can be even more dramatic after a full draw and a complete shot sequence.