massaging out set in bow after several hours of shooting your self bow

[Philipp A]

interesting discussion for sure. I am still however curious what actually happens within the cells for the bow to take on permanent string follow / set.

In fibre glass for example if you end up over compressing the fibres you end up "buckling" the fibres which would show up as little waves on the compression side. I am familiar with this from some fibre glass components.

It appears that buckling failure in wood is similar based on the article enclosed below (see section Strength of Wood):

https://www.doitpoms.ac.uk/tlplib/wood/printall.php

I am wondering whether set/string follow is simply a partial buckling failure that is not sufficient to cause a complete compression failure of the bow. That would assume that further damage is stopped when a balance is reached between the draw length of the bow and the reduced distance the bow has to be drawn under load due to the partial compression failure (the bow is softer).

If my theory is correct this would mean that a bow with some string follow / set would have a reduced draw weight at the same draw length when compared to its original fully tillered shape before string follow has "set" in.

Let me know whether I am totally out to lunch with my thinking on this.

[JW_Halverson]

Some years back the majority agreed that string follow and set are two different things.  Set was defined by the amount of decurve relative to the profile prior to any tillering and after allowing sting follow to relax and recover. 

Your massaging will take encourage the string follow to recover, but the set is...well, for lack of a better word, SET.

  How they can't be seen as degrees of the same thing is beyond me.

My hypothesis is that the set is permanent damage to the structure of the fiber.  String follow is temporary loss of elasticity that recovers in a period of time.

[Badger]

  You are correct it does reduce the draw weight. If you ever take the time to monitor how much draw weight you can loose it will scare you. A bow with a lot of set might have lost over 20# in the building process not from removing wood but from exercising  it in an over stressed state. Exercising a bow to get wood removal to register is often doing nothing but collapsing wood cells. That is why it is a good idea to go down 1" at a time at full draw weight If you are picking up inches just by working it you have a problem.

[Badger]

     Set is really fascinating. The set that is important is any recovery that is slower than your arrow. You can't measure set when a bow is at full draw but you can identify it and quantify it through a series of tests. If you unstring a bow and it has 2" of set it might really have 4" when the bow is at full draw. Set recovery starts slowing down as soon as you release the string. It might take a bow 2 seconds to recover the first 1/2"  10 min for the next 1/2" and 1 hour for the last 1/2" and then maybe a little more by the next day. The recovery actually starts during the shot sequence but anything slower than the arrow you loose out on.

[Philipp A]

Hi Badger, interesting observations. I have never thought of it in terms of set recovery during the shooting sequence. I guess based on your observation a bow that feels springy should also have less set during the draw sequence in comparison to one that feels like a noodle. I am also wondering whether hardwoods that have tight year rings are more susceptible to set than the ones with wider growth rings? Any observations on which bow woods are more susceptible to set than others?

[Jim Davis]

Well, folks are out to redefine archery terms again. I won't even bother to say which terms or which people. But you each know whether you are using a long-held definition that is in many of the old books, or are using what you have heard people use, or are just saying what  you like to think the word means.

Here's another thing many of you are prognosticating on without reference or deference to the knowledge of those who came before: ALL the early writers on bows, beginning at least as early as Roger Aschem, were insistent that a bow should NEVER  be bent backward and that doing so in the hope of repairing set only made the bow less strong and more likely to break.

But we DO like to think we know things and that others have no experience or knowledge that ranks with ours.

[Philipp A]

Reply to asharrow:

The reason for myself posting the subject was because I was seeking advice on whether this is harmful to the bow or not. You clearly are indicating that it is. So taking your advice (and that of others) it will be a good idea not to continue doing it. My bows have not suffered because of this habit (yet), so I guess I have asked the question in a timely fashion. I definitely appreciate your feedback!

Having said this, I don't think there is anything wrong in asking a question,  having a general discussion about set, string follow and what actually happens in the wood during that process.

Having curiosity is something that has served me well and it is the only way to further knowledge, either through the wisdom and experience of others or by experimenting yourself and seeing what goes right and what goes wrong and to educate yourself and to become better at whatever you set your mind to do.

[upstatenybowyer]

This discussion reminds me of something Badger wrote recently... "If we have to exercise the bow to register changes, we are actually damaging the wood. We don't want the wood to have any memory of ever being bent if possible."

He was talking about tillering, but I think it applies here as well. I do a lot of origami and it makes me think of how paper has memory. Once you crease paper, it never forgets that crease. In bow making, it's like set happens when the wood is stressed too much and as a result it gets "creased." Just like paper, wood never forgets that.

[George Tsoukalas]

Phil, was your bow wood dry? Jawge

[Badger]

Hi Badger, interesting observations. I have never thought of it in terms of set recovery during the shooting sequence. I guess based on your observation a bow that feels springy should also have less set during the draw sequence in comparison to one that feels like a noodle. I am also wondering whether hardwoods that have tight year rings are more susceptible to set than the ones with wider growth rings? Any observations on which bow woods are more susceptible to set than others?

  I could never identify a feature about wood that would take more or less set. Here is some more to confuse you. Some set isn't really even set. Sometimes the forward reflex we put in just doesn't hold and appears to have taken set. I think the best indicator is the less recovery after unstringing the better. Not stating this as a positive fact, it just appears this way to me after doing some tests.

[loon]

I think Korean bows take probably the most temporary string follow of all bows. But they are horn and sinew... a lot of sinew. They probably suffer from a lot of hysteresis - draw weight drops the more you hold at full draw? I think an overstrained wood/sinew bow would act similarly.

[willie]

I am wondering whether set/string follow is simply a partial buckling failure that is not sufficient to cause a complete compression failure of the bow.

My take on it is that all wood cells are not created equal. weaker cells yield and loose stiffness before the stronger, and a higher percentage of stronger cells makes for better wood.

wood typically being stronger in tension than compression, makes the stretching of cells on the back of the bow less critical, but different designs do maximize the benefits of the work done in tension.

I am also wondering whether hardwoods that have tight year rings are more susceptible to set than the ones with wider growth rings?

early/late wood ratio in a ring is commonly said to be more important than the ring count it's self.

[PatM]

Some years back the majority agreed that string follow and set are two different things.  Set was defined by the amount of decurve relative to the profile prior to any tillering and after allowing sting follow to relax and recover. 

Your massaging will take encourage the string follow to recover, but the set is...well, for lack of a better word, SET.

  How they can't be seen as degrees of the same thing is beyond me.

My hypothesis is that the set is permanent damage to the structure of the fiber.  String follow is temporary loss of elasticity that recovers in a period of time.

 That's why I said degrees of the same thing. Permanent damage is complete loss of elasticity, temporary is just that and the rest is undamaged elasticity.

 Why hasn't there been a petition for string follow longbows to be called "set longbows"?

[Philipp A]

To George: yes my wood was dry (9%). The bow actually doesn't have a lot of set (less than 1" when recovered). I just gotten into the habit of massaging the limbs after shooting....which I won't do anymore based on the feedback received 

To upstatenybowyer: I think what you are stating based on Badger's quote rings true with me as well...

To willie: I use HHB for my bows which is a diffuse porous wood, so the early / late wood ratio should not be deciding factor. I do know however that the wood has to be absolutely dry to prevent set. I think when I do get more set it is typically when I am not patient enough when tillering and overdrawing the bow before it is ready.

To Badger: yes you did indeed confuse me more  . Your quote: "I think the best indicator is the less recovery after unstringing the better" maybe you can elaborate a bit more

[George Tsoukalas]

Phil, I don't think bending it backwards  is a good idea either.

Regarding set and string follow...they are cousins.

This is how I see it.

String follow is when the bow appears to be strung when it is not.

Set is when the bow moves from its starting point when it was a stave.

Here's an example.

A stave starts with 3 in. of reflex. After tillering it retains 1 inch of reflex so it does not follow the string but it does have 2 in. of set.

Jawge