Author Topic: Deflex  (Read 542 times)

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Offline DC

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Deflex
« on: May 10, 2018, 12:09:30 pm »
Lately I've been making bows that are deflexed in the handle. The reflex in the limbs and the recurves bring the tips back to even or past the handle. They work very well. I'm wondering if it matters if the deflex is a little farther out the limb? If it doesn't matter then I could steam the deflex in rather than cutting and splicing.
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Offline Badger

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Re: Deflex
« Reply #1 on: May 10, 2018, 12:16:39 pm »
  D/C   I think where you notice the difference is that you can get much smoother bends when deflexed through the handle, much easier to deal with when Tillering. Aside from that I think you can match the performance pretty well deflexing past the handle. Just a bit more difficult and just my opinion for whatever it is worth.

Offline DC

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Re: Deflex
« Reply #2 on: May 10, 2018, 12:20:32 pm »
Opinions are what I'm after :) :)The decision rests with me.  Thanks
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Offline Marc St Louis

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Re: Deflex
« Reply #3 on: May 10, 2018, 05:17:19 pm »
Several people made deflex reflex bows like that many years ago.  I personally didn't like the looks of them and from what I remember they didn't seem to have top performance.  To me the geometry of bows with deflex in the limbs just seems to be off plus I think they have to be made a bit longer so the deflex part is not working, unless you sacrifice working limb length.
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Online Bayou Ben

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Re: Deflex
« Reply #4 on: May 11, 2018, 07:26:39 am »
DC, have you tried steaming the handle and bending it that way?  I've tried on a couple different woods and they didn't budge, but it could work if you are working with wood that responds well to steam.  Where do you plan to steam and implement the deflex? 

Funny thing, I currently just add deflex at glue up and have a slight bend through the handle, but I find I'm not getting enough so on my next build I'm going to try splicing billets (So I'm doing the opposite of what you want to do).  I would think you take more advantage of the deflex when you splice as the deflex is unstressed coming right out of the handle, but I'll confirm this after I get a few spliced deflexed bows under my belt.

« Last Edit: May 11, 2018, 07:50:37 am by Bayou Ben »

Offline DC

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Re: Deflex
« Reply #5 on: May 11, 2018, 08:03:31 am »
I've made a few bows that deflexed in the fades or had an even deflex in the middle third(or so) of the bow and they didn't perform as well as the recent ones that had deflexed handles. That made me wonder if it was just my building or whether others had noticed the same thing so I asked. :) I tried steaming the handle and that didn't work. I tried notching like here http://www.primitivearcher.com/smf/index.php/topic,63379.0.html
and wasn't too pleased with the result but maybe with practice it would get better. Splicing has given the best results so far it just irks me to cut a perfectly good stave in half but I can live with being irked once in a while ;). The last bow I made I spliced in 15 degrees of deflex. It's the one I tested here http://www.primitivearcher.com/smf/index.php/topic,63305.105.html. 40#@26.5" and it shot 185fps. These deflexed handle bows jumped my speed by 10-15fps. I made one that didn't have the sharp recurves, just the long reflexed limbs, and it was just a hair slower so I don't think the recurves themselves do much, they mostly look cool. I will be posting the one I tested when the oil is dry. One thing I should point out is that most of the numbers I post are for fresh bows. For the most part I build them, test them, and then they get hung on the rack. I make too many to shoot 500 or more shots on them all. Some I take a fancy to and I may shoot them for a month or so but so far as I keep getting faster bows they always seem to get replaced.
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Online Bayou Ben

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Re: Deflex
« Reply #6 on: May 11, 2018, 08:22:44 am »
I think you have answered your own question there.  Your bows have better performance with spliced handles....is it worth extra work to splice the handle considering your performance gains? 
I would think you benefit more with recurves on longer draws and shorter bows.  I could see your 26.5" draw not benefiting much from the recurve on the style of bows you've been making. 
 

Offline DC

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Re: Deflex
« Reply #7 on: May 11, 2018, 09:42:40 am »
I knew my spliced bows performed better, I just wondered inf anyone else had noticed it. And yes it's definitely worth it, I just don't like cutting good staves. If I had lots of billets it would be a done deal :).  The string is lifting of the bow at about 26", just shy of full draw so I think I would be getting the benefit of the recurves.
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Offline Badger

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Re: Deflex
« Reply #8 on: May 11, 2018, 09:55:37 am »
  I quit deflexing in the limb just because it seemed to make tillering harder. About 184 at 10 grains in where I topped out using teh straight handle with a little deflex in the limb. I like the deflexed joined handles much better I just don't like to go through the extra trouble. In recent years I have just been reflexing the outer limbs but it is still prone to more set if not extra careful. If you don't mind a little extra work it really is the best way to go.

Offline DC

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Re: Deflex
« Reply #9 on: May 11, 2018, 10:16:30 am »
I tried to make a splicing jig like Strunk's but after spending two days trying to get it consistent I gave up. I couldn't get the jig to hold small, round,lumpy staves consistently. I can get a splice ready for glue in about an hour now so it's not to bad.
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Online Bayou Ben

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Re: Deflex
« Reply #10 on: May 11, 2018, 10:37:20 am »
  I quit deflexing in the limb just because it seemed to make tillering harder. About 184 at 10 grains in where I topped out using teh straight handle with a little deflex in the limb. I like the deflexed joined handles much better I just don't like to go through the extra trouble. In recent years I have just been reflexing the outer limbs but it is still prone to more set if not extra careful. If you don't mind a little extra work it really is the best way to go.

That makes sense.   

After reading through a bunch of Marc's articles I finally got the concept of reducing stress on the major working part of the limb by adding deflex.  With my long draw, I'm excited to see what kind of doors spliced deflexed handles will open for me.  With my 6 month old I don't have the time I used to to play around with my bow ideas, but my next one will have a spliced heavily deflexed handle. 

DC, are you doing a tapered finger joint splice like Marc?
   


Offline DC

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Re: Deflex
« Reply #11 on: May 11, 2018, 01:13:10 pm »
I use a "Z" splice. I'm not sure if Marc does. I seem to remember him saying he used something else but I'm old, I could be wrong.
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