What is too much reflex??

[gstoneberg]

I have an elm thats similar. I think i started with about 4 inches of reflex and lot a lof of it quite quickly, more so that i would have with a flatter bow. No idea if that was my fault but i had read that a lot of natural reflex pulls out quite readily.

I really think most of the time we lose reflex it's early set.  In my case I hate to floor tiller and get to a short string as quick as I can.  Trying to string a highly reflexed bow the first time is like pulling it 12" or more and most of the time it isn't tillered well enough or far enough to take it.  Because the maximum leverage is right off the fades that's where the set occurs.  Fortunately, it automatically creates that deflex/reflex look I like.  Unfortunately, it represents lost performance, effectively negating the benefit I'd have gotten from the reflex in the first place.  So, now I'm taking my reflexed staves further on the floor and on the long string.  That makes me walk a tightrope of chasing good tiller while knowing I'm removing draw weight that will preclude much additional tillering if there's a problem on short string.  So far as often as not I miss weight.  This is why I prefer only mildly reflexed or straight staves.  I need to sit down with Pearlie sometime and have him show me how to tiller big reflex.

So, for me, I would say a lot of natural reflex can be pulled out quite easily by the impatient bowyer.

George

[Pappy]

I have done a few with 6 inches and like others have said,2 to 3 is about all I want. Yes sometimes you will wind up with 2 inches of reflex from a 6 inch start but if you think about  it you have 4 inches of set,start with 3 and wind up with 1 you have 2 inches of set. Plus they are a bear to get braced and very easy to miss weight.I started with an Osage limb bow once with 6 inches and wound up with 4 inches of rested reflex,it was a screamer and very smooth to shoot,but that is hard for me to do consistently,so I would rather start with 2 or 3. 
   Pappy

[Del the cat]

Hey George! 'Impatient Bowyer'? Have you been watchin' me through your magic spy glass again?
I've just pulled 4 1/2 " out of a pice of English Hornbeam...
I reckon you described the problems exactly as I found 'em.
Del

[gstoneberg]

I'm sorry my friend, I feel your pain.  I'm sure you'd rather not be like me.  Impatience is my worst enemy...that and not paying attention.  Fortunately, as I get older I'm just plain slower at building and tillering.  Gives me more time to realize I'm messing up.

Been thinking about starting that piece of yew from your neck of the woods.  I'm hoping a nice recurve similar to Gordon's would work well out of that stave.  What do you think?  It would make a nice hunting bow for this fall.  Uh-oh, I'm hijacking again...   No reflex in that yew (weak attempt to stay on-topic...).

George

[Badger]

     The question was how much is too much reflex. I feel if I don't hold at least 1/2 of what I put in I put in a bit too much or screwed up a bit when tillering. I built one the other day that is 75# at 28". I started with 3 1/2" reflex and finished with -1". After resting it goes back to 1/2" reflex. The bow is doggy. After resting the bow will pull about 82# on the first pull and the second pull 75#. They should be within 1# of each other so bow has been badly overstrained.

[dwardo]

     The question was how much is too much reflex. I feel if I don't hold at least 1/2 of what I put in I put in a bit too much or screwed up a bit when tillering. I built one the other day that is 75# at 28". I started with 3 1/2" reflex and finished with -1". After resting it goes back to 1/2" reflex. The bow is doggy. After resting the bow will pull about 82# on the first pull and the second pull 75#. They should be within 1# of each other so bow has been badly overstrained.

Would you say losing introduced reflex is the same as losing natural reflex?

Sorry to thread hijack

[Badger]

  Dwardo, I won't say I am 100% sure of this but I believe that loosing relfex is the same as taking set and the wood just doesnot respond the same after taking set. The yew bow I recently built had about 1 1/2" natural deflex, yet the string at brace felt rock hard. The above mentioned bow started off about straight but now the string is softer than it should be for the weight bow it is.

[dwardo]

  Dwardo, I won't say I am 100% sure of this but I believe that loosing relfex is the same as taking set and the wood just doesnot respond the same after taking set. The yew bow I recently built had about 1 1/2" natural deflex, yet the string at brace felt rock hard. The above mentioned bow started off about straight but now the string is softer than it should be for the weight bow it is.

I wonder again if there is a difference between the reflex caused by a natural growth curve and that caused by reaction wood, as in the tension wood half of a split taking reflex after splitting. Maybe the tension wood is used to taking the weight in some cases. I gather that the set caused early on is just dead mass which causes the sluggy feeling?
Rambling now.... 

[Badger]

   I wish I knew some way to test that out accurately beyond just experiencing and recognising it when it is happening. Their are several very easy steps to tell if a bow is being braced too soon. One you can simply lay your bow down on top of two elevated blocks, use a hand held scale to pull down on the handle and see what it reads to bring it down say 10", then check it again and see if it changed. If it changed the bow is being braced too soon. Same way with drawing a bow out on the tiller tree, anytime it drops in weight just from being pulled it is doing damage.

[gstoneberg]

What scale are you using to measure the weight?  I don't think my bow scale is accurate enough to use for what you're describing.

George

[Badger]

   I have an ultra sport 50 digital fish scale. Goes up to about 125#

[Danzn Bar]

Thanks for all of the responses.  This is great information from very knowledgable people. Thanks for passing it along.
I think I'll do what Jawge said "given a stave with natural reflex I'd even it off and go for it"

dwardo,
You make me think if this is natural reflex or not.  I found a pic where my friend and I split the log into staves.  The log came from a tree that was leaning at a 30 deg angle back in the woods, the tree was about 40 ft tall.  The log was split into quarters and only two of the quarters reflexed.  By chance were the reflex staves on the top of the tree holding the weight?  It didn't come from a curved log/limb to start with as Pappy noted, so would it be considered natural reflexed?

     The question was how much is too much reflex. I feel if I don't hold at least 1/2 of what I put in I put in a bit too much or screwed up a bit when tillering. I built one the other day that is 75# at 28". I started with 3 1/2" reflex and finished with -1". After resting it goes back to 1/2" reflex. The bow is doggy. After resting the bow will pull about 82# on the first pull and the second pull 75#. They should be within 1# of each other so bow has been badly overstrained.

Good info.............I now know why my first bow (hickory flat bow) first pull after brace was 52# and there after was 47#.  I overstress the bow during tillering.  I need to remember this one.

gstoneberg,
I do not have enough experience tillering to understand your comment "Impatience is my worst enemy...that and not paying attention"  Would you please take a little time and explain your comment a little more?

I don't consider good information "highjacking"
Thanks again for passing it along'
DB 

[gstoneberg]

gstoneberg,
I do not have enough experience tillering to understand your comment "Impatience is my worst enemy...that and not paying attention"  Would you please take a little time and explain your comment a little more?

OK.  Let me explain it with the debacle that was my last highly reflexed bow, a yew shorty.  It was about 52" long and each limb had about 6" of reflex.  One limb was reflexed when I got it, I heated the other limb and bent it to match.  It was supposed to be my hunting bow last fall.  Here's a picture:



I got it to floor tiller OK but it was a nightmare on the tillering setup on the long string.  It would not stay upright but would flip the moment I began pulling weight.  I had to hold the bow with one hand and and pull the rope to the pulley with the other.  I'd remove wood and nothing would change, so I'd remove more wood and nothing seemed to change.  Finally I decided to heck with it and tried to string the bow.  I could not pull it far enough to get it strung.  I tried again on the tree but unless I was holding the handle it would reverse on the tree every time.  I could not pull with 1 hand well enough to really exercise the bow.  I kept removing wood and trying to exercise it.  After a couple more wood removals I tried to string it again.  It strung easily this time with one limb  weaker than the other.  When I finished tillering it I had 35lbs at 27".  I heat treated it hoping to get 10 more pounds.  First pull after the heat treating it turned into toothpicks.

I was impatient, didn't work out a solution to the bow reversal problem and kept pushing because I wanted to finish the bow.  I should have paid more attention to how much wood I was removing.  Better yet I should have left it on the workbench the minute I got frustrated.  Because I didn't do those things I messed it up and then broke it.  Sadly, that's not the only example.

George

[PEARL DRUMS]

George I dont use a long string on any bows let alone highly reflexed bows.  I get them floor tillered to about 60-70#'s and brace them low. Then finish the tiller off and reduce weight. They generally stay put on the tree, if not I bar clamp them in place.

[crooketarrow]

  I reflex all my staves while green and have found out and thing over 3 inchs (I keep all of mine to 2 inchs no matter what the wood) and keep it even to each limb. Over stress that limb crushs wood cells no matter what type wood it is and causes exture stress causeing set and string follow. So to much of a good thing is'nt so good. WHERE HAVE I HERD THAT ONE BEFORE
  I do this becuase I do'nt use any heat on my bows anymore. You have 2 choises take some reflex out of the one limb by heating. Or tiller it like it is as you tiller you'll even out the reflex and hope it dos'nt put to much stess on the limbs.
  It's to late now but if I could'nt have reflexed it when it was green. I'd cut it off and move my handle untill I have more even reflex. Then tiller it out untill the limbs matched.