Primitive Archer

Main Discussion Area => Bows => Topic started by: DC on June 11, 2018, 12:51:59 pm

Title: Best way to pull out reflex
Post by: DC on June 11, 2018, 12:51:59 pm
I reflexed this Doug Maple on the caul I normally use. I steamed and then heat treated it and instead of relaxing a bit it took the exact shape of the caul. It has 8" of reflex. I'm sure a bunch of it will pull out. I plan on deflexing the handle but I thought I would try to get some of the reflex out first so I have a better idea how much to deflex it. I've exercised it about 50-60 times and it hasn't changed. Do you think that a steady strain(much like bracing it) for a few hours would assist in pulling out some reflex or should I continue exercising it?
Title: Re: Best way to pull out reflex
Post by: Badger on June 11, 2018, 01:23:15 pm
  Some will pull out when you tiler I imagine, I don't think it is a good idea to just strain it out all though with that much reflex you would still have a good shooter if you maintained 1/2 of it.  I am really impressed with your work here lately. I bet Mark is honored you chose his styles to model after. Mark is not an easy act to follow.
Title: Re: Best way to pull out reflex
Post by: DC on June 11, 2018, 01:45:11 pm
Thank you very much for the compliments but I think I just chose to copy the right guy :D.  I just thought that if I could somehow pull some out some of the reflex I wouldn't have to second guess the deflex. But now that you mention it the bulk of the pull-out does come later in the tillering. Maybe I'll try tillering it a bit more before I deflex. I'm just kind of clueless as to how much draw weight I will lose per degree of deflex. On another note, do you think that the draw length on a deflexed bow is extended equal to the amount deflexed. Like if I deflex the tips back 1" does that extend the draw length by 1"?
Title: Re: Best way to pull out reflex
Post by: Pat B on June 11, 2018, 02:05:42 pm
You might be better using heat to remove some of the reflex. I've done it a bit with naturally reflexed staves. With that much reflex you can over strain the bow just getting it to brace.
Title: Re: Best way to pull out reflex
Post by: TorstenT on June 11, 2018, 02:16:39 pm
How about making the deflex close to the handle, that you already mentioned, rather steep? That would result in a neet R/D shape, don’t you think?
Title: Re: Best way to pull out reflex
Post by: DC on June 11, 2018, 02:31:21 pm
Good thought Pat. There seems to be  a bit of a paradox here, if you just put in a little reflex it will pull out but if you get stupid about it, it stays :D
Torsten- I plan on splicing the handle and putting some deflex in. I prefer spliced in rather than steamed in. It just seems easier to tiller without the extra bend.
Title: Re: Best way to pull out reflex
Post by: Bayou Ben on June 11, 2018, 03:25:38 pm
That's some aggressive reflex you got there.  I agree you don't want to strain the bow to relieve some of it. 

"On another note, do you think that the draw length on a deflexed bow is extended equal to the amount deflexed. Like if I deflex the tips back 1" does that extend the draw length by 1"?"

I would be interested to see the answer to that question as well.  Seems that there's too much going on to give a rule of thumb like 1" deflex equals 1" extra draw, but I'm sure guys like Marc who have a lot of experience with deflexed handles can estimate. 
Title: Re: Best way to pull out reflex
Post by: bjrogg on June 11, 2018, 03:36:12 pm
I agree with Badger D.C. Your knocking out some pretty awesome bows.
I think if you asked Ed he'd tell you to reverse string that baby lay a couple courses of sinew on and put it by the wood stove for several months. Then you could put some horn on the belly and tiler it out. Just kidding but sure looks like the start of one of Ed's composites.
Bjrogg
Title: Re: Best way to pull out reflex
Post by: bushboy on June 11, 2018, 04:13:09 pm
If you placed belly side up and barclamped in the middle and heated appling heat and slowly tighten the clamp it would work I think ?but I've never worked dm.
Title: Re: Best way to pull out reflex
Post by: Marc St Louis on June 11, 2018, 05:28:58 pm
I don't know what that species of Maple is like for strength in tension but I made several like that many years ago out of Elm, BL and HHB.  That amount of reflex is manageable, just a bit tricky to tiller

Here is a picture of the first Elm bow I ever heat-treated, this is the one I wrote an article on.  You can see that it has a fair amount of reflex



Title: Re: Best way to pull out reflex
Post by: bjrogg on June 11, 2018, 06:21:59 pm
Looks nasty Marc
Bjrogg
Title: Re: Best way to pull out reflex
Post by: DC on June 11, 2018, 06:27:06 pm
Is that the finished bow Marc or did some of that reflex pull out? It is, as you put it, a fair amount :D :D
Title: Re: Best way to pull out reflex
Post by: bjrogg on June 11, 2018, 06:40:48 pm
I'd like to read the article on that one.
Bjrogg
Title: Re: Best way to pull out reflex
Post by: Bob Barnes on June 11, 2018, 07:44:41 pm
"Burnt Offerings"?  I remember that bow/article  Marc...
I think sinew and that profile could be magic..   :OK
Title: Re: Best way to pull out reflex
Post by: Danzn Bar on June 11, 2018, 07:57:14 pm
Sinew and osage is magic.....
Title: Re: Best way to pull out reflex
Post by: Danzn Bar on June 11, 2018, 07:59:00 pm
And it's still shooting today...….
DBar
Title: Re: Best way to pull out reflex
Post by: Danzn Bar on June 11, 2018, 08:13:26 pm
There's no such thing as too much reflex ….if it can be tillered properly...
DBar
Title: Re: Best way to pull out reflex
Post by: Marc St Louis on June 11, 2018, 08:44:33 pm
Is that the finished bow Marc or did some of that reflex pull out? It is, as you put it, a fair amount :D :D

That was the bow before tillering.  This was after

Title: Re: Best way to pull out reflex
Post by: Badger on June 11, 2018, 08:55:54 pm
   I kind of think of wood as I do athletes, some wood has more potential than others even of the same species. I don't think many of us have figured out a way to tell ahead of time which pieces of wood have the exceptional athletic ability but building bows with a lot of reflex will certainly separate the average wood from the exceptional wood.

    I have built my share of heavily reflexed bows and in my case I have seen a few different thing happen. Sometimes I don't loose much reflex but the limbs are just a tad rubbery and I don't have as much early draw weight as I would expect from such an extreme design. When a limb gets so thin as it sometimes does in heavily reflexed designs the tension wood can pull it back into shape even though the belly has been badly damaged. Other times I have lost a good bit of the reflex to set but the bow still was pretty hard at brace height and shot very well. I believe that when we are working with wood we are best off to stay within its limitations, sinew backed bows can tolerate much more reflex because the sinew is stretching. I think in most cases too much reflex surpasses the limits of the point of diminishing returns.
Title: Re: Best way to pull out reflex
Post by: bjrogg on June 12, 2018, 06:12:06 am
Suspect your probably right Badger in most cases. Especially with longer draws. That's why I said Ed would probably put on sinew and horn. I know he says it makes a durable bow that way. Seem like for me with my short draw length a bit more reflex if I can hold it really speeds up my bows.
Bjrogg
Title: Re: Best way to pull out reflex
Post by: Marc St Louis on June 12, 2018, 07:27:16 am
   I kind of think of wood as I do athletes, some wood has more potential than others even of the same species. I don't think many of us have figured out a way to tell ahead of time which pieces of wood have the exceptional athletic ability but building bows with a lot of reflex will certainly separate the average wood from the exceptional wood.

    I have built my share of heavily reflexed bows and in my case I have seen a few different thing happen. Sometimes I don't loose much reflex but the limbs are just a tad rubbery and I don't have as much early draw weight as I would expect from such an extreme design. When a limb gets so thin as it sometimes does in heavily reflexed designs the tension wood can pull it back into shape even though the belly has been badly damaged. Other times I have lost a good bit of the reflex to set but the bow still was pretty hard at brace height and shot very well. I believe that when we are working with wood we are best off to stay within its limitations, sinew backed bows can tolerate much more reflex because the sinew is stretching. I think in most cases too much reflex surpasses the limits of the point of diminishing returns.

I agree Steve.  It's all in the wood and the only way to find out is to try it.  If one can get their hands on top grade Elm then you can't ask for better when making highly reflexed bows, sadly I haven't cut any top grade Elm in awhile.

That is a lovely bow DB
Title: Re: Best way to pull out reflex
Post by: Danzn Bar on June 12, 2018, 03:06:29 pm
Thanks Marc...……...
Title: Re: Best way to pull out reflex
Post by: bradsmith2010 on June 12, 2018, 05:08:33 pm
deflex the handle and go with what you got,, if you scared,,, deflex it a bit more, (lol)
Title: Re: Best way to pull out reflex
Post by: DC on June 13, 2018, 12:22:27 pm
Deflexed, doesn't look quite so daunting now. I haven't taken any reflex out. It's 40#@23" so I'm glueing on tips to brace it
Title: Re: Best way to pull out reflex
Post by: Bayou Ben on June 13, 2018, 12:48:04 pm
Looks awesome! I wouldn't pull anything out.  Let it ride and see what you get. 
Title: Re: Best way to pull out reflex
Post by: Bayou Ben on June 13, 2018, 12:51:26 pm
And let us know how bracing it goes.  I'm working on one right now that has less reflex than that and it's a beast to brace.
Title: Re: Best way to pull out reflex
Post by: bjrogg on June 13, 2018, 01:11:48 pm
I like it DC. It will probably feel a lot heavier at brace than it really is. Seems like it's Easy to get under Your intended draw weight with these.
Title: Re: Best way to pull out reflex
Post by: DC on June 13, 2018, 01:18:37 pm
This stave was very bendy. When I roughed it out at 3/4" thick it was almost at final weight, 40#. If I was making a straight bow it would have come in underweight I'm sure. I evened out the thickness taper before I reflexed and heat treated. This 23" is without any tillering yet. I've got 4" to get it right.
Title: Re: Best way to pull out reflex
Post by: DC on June 13, 2018, 02:11:10 pm
When I braced it, it was 40#@ 27" and in there somewhere I lost at least 2" of reflex. It was easy to brace. I've done no tillering and it was so close. So I've got no weight left for tillering and it's bending in the middle too much. It's 64" so I might spike it an inch or I might tiller it out properly and see what I get. I've never seen such a bendy stick. Harvested in 2014 so it's as dry as anything gets around here. Weighs 500 grams (17+ oz) Rats, I was hoping for better, I'll leave the next one thicker. :)
Just for the hell of it I put it in the shooting machine 40#@28" 10 gpp I got 170 fps.
Title: Re: Best way to pull out reflex
Post by: Bayou Ben on June 13, 2018, 02:48:02 pm
Surprised you didn't get more weight with that thickness.  I know it's maple, but look at your thickness vs how thin Dazn Bar's osage is. 
Title: Re: Best way to pull out reflex
Post by: DC on June 13, 2018, 02:57:36 pm
It surprised me too. Anyway here I am now. Thought it over while enjoying a plate of spaghetti. :) I decided I'm going to tiller it to my satisfaction and then think about piking. I'm sort of getting used to the bend but we'll see what I get. I'm starting with this.
Title: Re: Best way to pull out reflex
Post by: bradsmith2010 on June 13, 2018, 06:14:56 pm
looking good, glad its coming along for you, I learned from your post,, great info :KN
Title: Re: Best way to pull out reflex
Post by: DC on June 13, 2018, 08:36:04 pm
looking good, glad its coming along for you, I learned from your post,, great info :KN

Yeah, things not to do :)
Title: Re: Best way to pull out reflex
Post by: Badger on June 13, 2018, 09:08:32 pm
  I was going to warn you about loosing weight when you brace the bow, unavoidable on that design. You did a beautiful job and I imagine it will still perform well but just a good example of surpassing the limitations of wood. I think some good pieces of wood could have handled that, you were pretty close.
Title: Re: Best way to pull out reflex
Post by: Badger on June 13, 2018, 10:17:54 pm
  One thing interesting about playing with bows whose limbs are at different string angles to the bow string and direction of pull. The part of the limb ( fade) have a much bigger reaction to the pulling than the reflexed mid limbs because they have a much higher string angle. You always see horn bows pre-bent in the areas they want to bend for this same reason.
Title: Re: Best way to pull out reflex
Post by: Marc St Louis on June 14, 2018, 08:13:15 am
Looks pretty darn good.  It should have good performance
Title: Re: Best way to pull out reflex
Post by: DC on June 14, 2018, 09:35:58 am
So far it doesn't. I evened it out a bit and that dropped it to 35#. So I piked it 1 1/4" (the length of the overlay) off each end and that brought it up to 38#@28". It shot in the high 160's. I'm beginning to wonder if this isn't the compression side of the tree. I mark them now but back in 2014 I didn't.
Title: Re: Best way to pull out reflex
Post by: bjrogg on June 14, 2018, 09:55:46 am
Maybe some sinew?
Bjrogg
Title: Re: Best way to pull out reflex
Post by: DC on June 14, 2018, 10:21:48 am
I think it's a bit on the long side for sinew but I've only done one sinew bow. I tend to think of sinew on short bows. It's not high on my list of things to do. Backing a bow with other wood or boo is about as far as I want to stray from self bows. Wouldn't the deflex be counter productive on a sinewed bow? I don't know about that. I do have a bag full of sinew though. I think I have to take some time off bow making to do summer maintenance on the house so that will give me time to ponder. :) :)
Title: Re: Best way to pull out reflex
Post by: bjrogg on June 14, 2018, 11:14:08 am
All good questions DC. I'm thinking your probably right in your line of thinking. I haven't done a sinew bow so certainly can't give you a answer. Just kinda thought if you were going to keep shortening it and it was weak in tension maybe it would help. Have to talk to someone smarter than me or give it a try to find your answers.
Bjrogg
Title: Re: Best way to pull out reflex
Post by: bradsmith2010 on June 14, 2018, 03:12:06 pm
sinew would work,, you just might have to extend the draw, ,but maybe not, worth a try,,you would definitely learn something and me too (-P

ok I dont know how long the bow is, so I am just spit balling
but if you put sinew on ,,, it gonna go up in weight,,and will probably shoot the arrow harder,,
how effecient,, hmmmm  well depends on if you get some reflex back in the bow,, maybe recurve the tips a bit,, etc,,,,
but I feel like getting to 170 is way doable,,

I dont know that much about maple,, but there is a nice shooting bow in there with sinew on it,,its easier I think than  backing with wood,,,
but thats just me,, I think its a bit more forgiving,,

sometimes I have made sinew bows and they start to shoot really well before I draw them to half the bows length,, or when they are a bit to long,, but the chrono, tells me they are shooting nice,,I have even gone past the shorter draw to have the loss of reflex off set what gain I thought I was gonna get,,,, the sinew bows shoot so nice, I think you would enjoy it,, :OK (-S
Title: Re: Best way to pull out reflex
Post by: Badger on June 14, 2018, 05:27:42 pm
  DC, if you would have done no set tillering on that one it might have ended up at 35# but it would have been a fast 35#. Let the bow dictate the weight instead of the bowmaker.
Title: Re: Best way to pull out reflex
Post by: DC on June 14, 2018, 06:49:37 pm
I'm still trying to learn no set. Because I usually heat treat and put a little or a lot of reflex in if I dropped my weight expectations every time I noticed a little set I would end up with nothing. I'll get it eventually. :) This one is now backed with hard maple and the epoxy is curing. It went fairly quickly but the glue line will be the proof. Hopefully it will make a replacement for the East meets West bow I posted a while back. At the time I thought the knots on it were too much and after only 100-200 shots it's starting to pinch at two knots. This one will be virtually the same but with a heat treated belly.
Title: Re: Best way to pull out reflex
Post by: Springbuck on June 15, 2018, 05:07:26 pm
 DC,  you do have a knack for bows, but your real talent seems to be starting some of the most interesting discussions around here.  ;D ;D   Lots of good stuff to read, and here's my input.

DC:  "I plan on deflexing the handle but I thought I would try to get some of the reflex out first so I have a better idea how much to deflex it."

   I would have done what you ended up doing; deflexing first and then taking a look at what you have.  When I have staves that DRY into that much reflex, I almost always take some out of the middle with heat, and leave what I think I can manage in the outer 1/3 of the limbs or so.  I'm curious, what did the raw stave looked like before heat reflexing?

As yet unproven, my theory is that if I add reflex to a straight stave with dry heat, I'm extending the belly in a way that may allow it to take back some by set, despite the remarkable things a good toasting does to a belly.   That's still beneficial, of course, unless I then kill it during tiller.

  BUT!!  If I start with a stave that dried in to 9" of reflex or was naturally already reflexed, and pull back the middle of the bow to flat or even deflexed to arrive at a manageable an=mount of reflex, then I have COMPACTED the belly using heat.  That area should be less prone to taking set, and that's where the limbs will work most, so I'm happy.   Perhaps.

Badger: " I don't think it is a good idea to just strain it out all though with that much reflex you would still have a good shooter if you maintained 1/2 of it."  Like others have said, I likewise agree.  Losing more than a little reflex (or taking a lot of set) to strain means to me I overstrained the wood.  It seems obvious that crushed wood will not have the cast of pristine wood, regardless of profile.  It gets muddy if you compare an over-strained but reflexed profile to a pristine straight, bow, I suppose.

But, my practice is to deflex anything I want deflexed with heat rather than letting set do it for me. If I do that I rarely see it move due to strain.

DC:  "There seems to be a bit of a paradox here, if you just put in a little reflex it will pull out but if you get stupid about it, it stays." 

Hmmm....  I need to think about this.  I hadn't noticed the same thing myself, but I confess, i am scared of reflex much more than 3-4", unless I'm pairing it with some defelx near the middle.  Marc's bows look really intimidating to tiller.
Title: Re: Best way to pull out reflex
Post by: Springbuck on June 15, 2018, 05:26:18 pm
DC:  "On another note, do you think that the draw length on a deflexed bow is extended equal to the amount deflexed. Like if I deflex the tips back 1" does that extend the draw length by 1"?

  I think by more than that. Just like low bracing relives strain on wood by a surprising amount, I think deflexing does, too.  But, like so much in bowyery there is a trade off in the F/D curve, etc.. 

DBar:  "There's no such thing as too much reflex ….if it can be tillered properly..."  I want this to be true, and I think it is true in everyday life, and within reasonable limits.  I just doubt any wood is strong or flexible enough to take on, say tips-touching reflex, like a Korean horn bow, be wrestled to brace, then full draw, without either breaking or the belly never recovering.

Badger:  "I was going to warn you about loosing weight when you brace the bow, unavoidable on that design."

 Steve, do you know WHY this happens?  Is it unavoidable?  I noticed it most back when I was making lots of laminated R/D bows with full length cores/bakings. I was forcing the middles into glued in deflex at the handles.  This of course would have the opposite effect of Perry-reflexing, right?  So I left more mass there and made that area bend less to compensate, but I remember a some bows taking a lot of set a few inches out past the fades, but before mid-limb, where the Perry effect would have been well established.  Similar phenomenon, or just geometry induced extra strain? 

DC:  "I'm beginning to wonder if this isn't the compression side of the tree. I mark them now but back in 2014 I didn't."   Now, here I have not noticed a difference, but it could be the trees I'm using.  I often take the "down" side of barely leaning elm, ash, etc  specifically because the wood will hold fine in tension and there are fewer knots.  The "up" sides totally do want to dry in to more reflex.

  DC:  "I tend to think of sinew on short bows."

          To me 60"  IS a pretty short bow, but not so short it REQUIRES sinew.

         "Wouldn't the deflex be counter productive on a sinewed bow?"

            I don't think so, necessarily.  It wouldn't be detrimental, I don't think.  IF the bow needed it at all, wherever the bow bends a lot may benefit.
Title: Re: Best way to pull out reflex
Post by: DC on June 15, 2018, 05:39:09 pm
.  I'm curious, what did the raw stave looked like before heat reflexing?

It was pretty straight as far as reflex was concerned but it had a bunch of twist and a crook in each limb. it was a bit of a pain to work because I had to remember where it used to be bent when I was trying to reflex it. While I was reflexing it I also had a wrench on it to keep the twist from coming back

Quote
As yet unproven, my theory is that if I add reflex to a straight stave with dry heat, I'm extending the belly in a way that may allow it to take back some by set, despite the remarkable things a good toasting does to a belly.   That's still beneficial, of course, unless I then kill it during tiller.

  BUT!!  If I start with a stave that dried in to 9" of reflex or was naturally already reflexed, and pull back the middle of the bow to flat or even deflexed to arrive at a manageable an=mount of reflex, then I have COMPACTED the belly using heat.  That area should be less prone to taking set, and that's where the limbs will work most, so I'm happy.   Perhaps.
Yup and i think a natural bend is even better. PatM said a while back that a backed bow with the reflex glued in holds the reflex better because the backing is actually shorter than the belly. I think a stave with a natural bend is like that.

Quote
DC:  "There seems to be a bit of a paradox here, if you just put in a little reflex it will pull out but if you get stupid about it, it stays." 

Hmmm....  I need to think about this.  I hadn't noticed the same thing myself, but I confess, i am scared of reflex much more than 3-4", unless I'm pairing it with some defelx near the middle.  Marc's bows look really intimidating to tiller.
There may have been a touch of frustration in that statement :) I have now rasped the back off and glued on a hard maple back. I returned the reflex/deflex to about what it was when I started. After tillering for about three hours I'm now at 40#@15" on a shortish string The picture show how it is now. It feels like a bow this time. Last time(with the natural back) it felt like a noodle
Title: Re: Best way to pull out reflex
Post by: bradsmith2010 on June 15, 2018, 05:43:31 pm
well ok then,, proceed,,  :D
Title: Re: Best way to pull out reflex
Post by: Badger on June 15, 2018, 05:44:44 pm
      I never heard that before about the glued in back being shorter but in all honesty it is so simple yet makes so much sense. That probably is the best explanation for why the Perry reflex works.
Title: Re: Best way to pull out reflex
Post by: Badger on June 15, 2018, 05:46:07 pm
  I like that profile, I imagine your limbs will be considerably thinner this time around.
Title: Re: Best way to pull out reflex
Post by: DC on June 15, 2018, 05:51:29 pm
I really hadn't noticed a difference between tension and compression wood before but some people on here that know way more than me claim that there is a difference. I think either Weylin or Vinemaplebows have said they won't even use compression Vine Maple. Douglas is similar to Vine. This bow just started me thinking that they were right.

As far as sinewed deflex bows goes I just thought that sinew wants to be strained and deflexing relieves strain. That's where that was coming from.

Badger- I think my comment when PatM said that was,"It can't be that simple can it?"
Title: Re: Best way to pull out reflex
Post by: Badger on June 15, 2018, 05:53:17 pm
  Deflexing does relieve strain but that design of yours has plenty of strain and is an excellent candidate for sinew.
Title: Re: Best way to pull out reflex
Post by: DC on June 15, 2018, 05:56:21 pm
  I like that profile, I imagine your limbs will be considerably thinner this time around.
Yeah, I just hope I don't scrape off all the heat treated wood. One of the things I don't like about backed bows is that you're very limited as to how much heat you can hit them with.
Title: Re: Best way to pull out reflex
Post by: Springbuck on June 15, 2018, 08:09:03 pm
"Last time(with the natural back) it felt like a noodle."

That's very interesting.  Got me wondering if there is a logical/physical limit to reflexing due to the back not holding the tension (starting off compressed), rather than belly strain, instability, or any of the other things I'm usually worried about re: excessive reflex. 

I have had great luck with some bows that dried into lots of reflex, where I took some back with heat and left a just a few inches. 

Good stuff guys.
Title: Re: Best way to pull out reflex
Post by: DC on June 15, 2018, 08:27:42 pm
I think the next thing to try is kerfing the whole bow. Very neatly and carefully saw of the back. Smooth it out a bit and glue it back on with some reflex. It would have to be a pretty good stave without to many dips or lumps.
Title: Re: Best way to pull out reflex
Post by: DC on June 20, 2018, 12:27:05 pm
OK I finished this off. I backed it with Hard Maple but tried to leave everything else the same. It started out with 3" of reflex and by the time I was finished it had taken 4" of set. It was very close in appearance and performance to the natural Doug Maple back. I did see 183 fps @ 10gpp but after finishing and shooting a bit that dropped to 176-177. I'm thinking that a Doug Maple belly has to be wider than 1 1/4". Maybe 1 3/4" next time. It ain't yew but it's a good wood. :)
Title: Re: Best way to pull out reflex
Post by: Badger on June 20, 2018, 12:38:03 pm
   I don't think Doug maple is even considered a bow wood. I have made a lot of self bows from it but never a laminated. I usually go about 2 1/4" on the self bows for 50#. Do you know the mass weight of this bow. Not bad performance but this design should be hitting over 182 as it did on the one shot.
Title: Re: Best way to pull out reflex
Post by: DC on June 20, 2018, 12:44:17 pm
420 grams no string. I was happy with the 183 but it just started diving.