# Bow Building - A Question about Set



## kegan (Aug 28, 2006)

First of all, set is defined as the total amount the bow follows the string from its original position, with no mention as to how or the effects.

It is caused, however, by stress. Usually as a result of overstress. A bow that is too narrow for the draw weight or too short for the draw length, one with a hinge or built when the wood is too wet or not dense enough will take set. However, every wood bow takes a little set. As a wooden bowyer, your goal is to minimize that set. Fiberglass takes NO set because of the elasticity of the mateial. As a belly lamination it can take any amount of compression and not fail- unlike wood. Coupled with a lam on the back to insure high tensile strength, such a bow is "impervious" to abuse, at least compared to a selfbow under normal conditions.

A well designed bow can take less than an inch of set and remain that way despite long strung times and hard shooting sessions. Making sure the wood is at an optimum moisture content, tillering to avoid overstressing any part of the limbs, and making sure that the design you are building does not ask too much from the materials you are using all minimize set. Lately I've been able to tiller my hickory flatbows out so they hold at only an inch or so of set/string follow (I don't induce reflex).

Red oak is a relativley light, weaker wood. It cannot take the same stress and narrow design as say, hickory or Osage. Likewise, it is not as elastic. For most red oak bows, at 66" long with 9" on nonbending handle area and drawing 55# at 28" will need limbs a full 2" wide to avoid more than an inch to an inch-and-a-half of set. Most of the red oak bows built from boards I see are normally only 1 1/2" wide with a rounded belly. Not exactly built for performance. 

On my site there's a part of building a selfbow with a section on "No Set Tillering." I picked this method up from some VERY skilled wooden bow makers and it has helped me TREMENDOUSLY. Likewise, as I mentioned about design matching materials, you should find that ipe and hickory will not take set like your red oak does. Quite the opposite. Ipe has a specific gravity of .9 to over 1.0. That means some ipe bows sould be as narrow as 1 1/2" and pull 100#. 

Please feel free to PM me if you have any questions, I'd be happy tp help as much as I can.


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## Leafwalker (Oct 7, 2008)

kegan said:


> Most of the red oak bows built from boards I see are normally only 1 1/2" wide with a rounded belly. Not exactly built for performance.


Ha! You've seen my bow, have you? :smile:

Kegan, I almost PM'd you directly but figured other people would want to hear the response. I appreciate the quick, complete answer, thanks! I've got some wood to order!

And now for a follow-up question. Is there a resource/website that people are going to when they want to find out the properties of wood? You mentioned the specific gravity - I haven't seen that on the websites I've visited. Pete Ward's site is great for colors of woods, but not all the pictures show and the details aren't on all of them.


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## kegan (Aug 28, 2006)

I have a very small list of woods and their SG on my site, as well as a few notes on cutting and seasoning. There's a chapter in Traditional Bowyer's Bible vol. 4 on many, many bow woods and their density/characteristics. 

If you have any woods in mind though please give me a list and I'll do my best to give you the SG


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## Leafwalker (Oct 7, 2008)

kegan said:


> If you have any woods in mind though please give me a list and I'll do my best to give you the SG


I've got a whole list of woods I'd like to learn more about, and you'll probably get carpal tunnel trying to type in all the answers. I do appreciate your willingness to help, though.

So I should probably pick up the bowyer's bible set of books, but what makes a good limb versus a good riser? I see a lot of commercial bows with the same woods for limbs and it looks like any wood will work for a riser. Thoughts?


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## elk country rp (Sep 5, 2005)

hickory & ipe- that's a match made in heaven! 

if you do a search in the build along subforum, you'll find quite a few HBI's in a wide range of size & draw weight. i have an HBI ( http://www.archerytalk.com/vb/showthread.php?t=1120671&daysprune=-1 ) that started with 2 1/2" of reflex and still has 1 3/4". 3/4" set isn't bad- especially after thousands of arrows (some of them waaaay too light, too), and a pile of rough days spent hunting elk in the backcountry. it even killed an elk on its first elk hunt!

i'd put a hickory backed ipe longbow up against a fiberglass longbow any day. :darkbeer:


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## Leafwalker (Oct 7, 2008)

elk country rp said:


> hickory & ipe- that's a match made in heaven!
> 
> if you do a search in the build along subforum, you'll find quite a few HBI's in a wide range of size & draw weight. i have an HBI ( http://www.archerytalk.com/vb/showthread.php?t=1120671&daysprune=-1 ) that started with 2 1/2" of reflex and still has 1 3/4". 3/4" set isn't bad- especially after thousands of arrows (some of them waaaay too light, too), and a pile of rough days spent hunting elk in the backcountry. it even killed an elk on its first elk hunt!
> 
> i'd put a hickory backed ipe longbow up against a fiberglass longbow any day. :darkbeer:


That's a sweet bow! Thanks for letting me know what kind of set your reflex has taken on - I've only put a few hundred arrows through my red oak bow and it's starting to look like a crescent moon. It's kind of depressing really - I spent more time making the bow than I feel I got shooting it before it weakened. I've got the ipe and hickory on the way, plus rosewood and zebrawood for the riser.

Normally I wait all year for hunting season to start, but I'm kinda looking forward to it ending so I can work on this bow! :teeth:


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## kegan (Aug 28, 2006)

Rob's the HBI master! If you have questions on them, he's the one to ask!

For selfbows, you want to use the densest wood practical or available. I don't usually glue risers on selfbows but if you do the same goes for fiberglass laminated bows. For glass bows, the limbs should be a very light material and the risers should be very heavy and dense.


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