Author Topic: Best way to pull out reflex  (Read 1095 times)

0 Members and 1 Guest are viewing this topic.

Offline DC

  • Member
  • Posts: 5914
Re: Best way to pull out reflex
« Reply #30 on: June 13, 2018, 12:08:24 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.
Vancouver Island

Offline bradsmith2010

  • Member
  • Posts: 2631
Re: Best way to pull out reflex
« Reply #31 on: June 13, 2018, 03:25:44 pm »
looking good, glad its coming along for you, I learned from your post,, great info :KN

Offline DC

  • Member
  • Posts: 5914
Re: Best way to pull out reflex
« Reply #32 on: June 13, 2018, 05:46:52 pm »
looking good, glad its coming along for you, I learned from your post,, great info :KN

Yeah, things not to do :)
Vancouver Island

Offline Badger

  • Member
  • Posts: 7038
Re: Best way to pull out reflex
« Reply #33 on: June 13, 2018, 06:19:20 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.

Offline Badger

  • Member
  • Posts: 7038
Re: Best way to pull out reflex
« Reply #34 on: June 13, 2018, 07:28:42 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.

Offline Marc St Louis

  • Administrator
  • Member
  • Posts: 6800
  • Keep it flexible
    • Marc's Bows and Arrows
Re: Best way to pull out reflex
« Reply #35 on: June 14, 2018, 05:24:03 am »
Looks pretty darn good.  It should have good performance
Home of heat-treating, Corbeil, On.  Canada

Marc@Ironwoodbowyer.com

Offline DC

  • Member
  • Posts: 5914
Re: Best way to pull out reflex
« Reply #36 on: June 14, 2018, 06:46:46 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.
Vancouver Island

Offline bjrogg

  • Member
  • Posts: 5139
  • Cedar Pond
Re: Best way to pull out reflex
« Reply #37 on: June 14, 2018, 07:06:34 am »
Maybe some sinew?
Bjrogg
A hot cup of coffee and a beautiful sunrise

Offline DC

  • Member
  • Posts: 5914
Re: Best way to pull out reflex
« Reply #38 on: June 14, 2018, 07:32:36 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. :) :)
Vancouver Island

Offline bjrogg

  • Member
  • Posts: 5139
  • Cedar Pond
Re: Best way to pull out reflex
« Reply #39 on: June 14, 2018, 08:24:56 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
A hot cup of coffee and a beautiful sunrise

Offline bradsmith2010

  • Member
  • Posts: 2631
Re: Best way to pull out reflex
« Reply #40 on: June 14, 2018, 12:22:54 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
« Last Edit: June 14, 2018, 12:33:10 pm by bradsmith2010 »

Offline Badger

  • Member
  • Posts: 7038
Re: Best way to pull out reflex
« Reply #41 on: June 14, 2018, 02:38:30 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.

Offline DC

  • Member
  • Posts: 5914
Re: Best way to pull out reflex
« Reply #42 on: June 14, 2018, 04:00:25 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.
Vancouver Island

Offline Springbuck

  • Member
  • Posts: 1541
Re: Best way to pull out reflex
« Reply #43 on: June 15, 2018, 02:18:14 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.

Offline Springbuck

  • Member
  • Posts: 1541
Re: Best way to pull out reflex
« Reply #44 on: June 15, 2018, 02:37:06 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.