How to measure set

[Azmdted]

Hi all,

I just completed a hickory fire hardened bow IAW the Shannon video.  I enjoyed doing it this way, next time I will bring a hotdog and cook it over the coals while I'm watching the bow.  But my question here is about how to measure set.  Hopefully this won't turn into a set v string follow discussion, but if I'm using the wrong terms please correct me.  Here are the basic stats:

Off the caul after hardening but before serious tillering:  5" reflex
After tillering but before shooting:  3" reflex
After putting almost 400 arrows down range with 12 hours of rest:  2.25" reflex
After unstringing after 30 shots:  1.25" reflex

I just read in TBB1 that set should be measured immediately after unstringing.  I'm thinking that my set is 1" (2.25-1.25)  or, would it be 1.75" as measured from the original tillering reflex? 

It's 67" NTN, 29" DL, 49# after tillering, but 46# after getting shot in and finished.  After 30 shots the weight bottoms out at 42#, but then goes back to 46# after a rest.  After a few days of shooting it I found a great deal on a Ballistic Precision Chronograph on Amazon and I'm now playing with arrow speed, which is very interesting.  My first five shots of a session will average 163 fps, but after 30 shots my fps is down to 155.  I think that all makes sense considering the set and decrease in draw weight as I shoot.

[Dances with squirrels]

I like to be brutally honest with myself. If in fact I bother to measure it, I count all set that it took from the beginning... that is, measured before any flexing begins, to freshly unstrung after shooting(within the first minute or so). So in this case, (off the caul 5" of reflex) to (after shooting 1.25" of reflex) = 3.75" of set.

Others will figure it other ways, ignoring some of the set it took to make themselves feel better... but like I said, I like to be brutally honest with myself... which sometimes stings at first, but ultimately works out better for me and my bows.

[Azmdted]

Thanks, no problem with brutal honesty here.  I figured that was likely the answer.  I think in this case I followed the thin clues in the Shannon video too literally.  They said to fire it when it 'was barely bending', so that's what I did.  Which I think caused some over stressing as I tested the floor bend after that.  Next time I'll wait till it's about done with floor tiller and be more gentle on stressing the bends.

Live and learn.  Thanks again.

[PatM]

I measure set by pretending someone gifted the bow to me and didn't tall me anything about its original profile or manipulation.

[silent sniper]

How I measure set is rested reflex minus just unbraced reflex on a finished bow.. I don’t worry too much about loosing reflex while building heavily reflexed bows, some lose is to be expected when you are stressing wood like that.

[willie]

Next time I'll wait till it's about done with floor tiller and be more gentle on stressing the bends.

if the stave was a bit green or the fire hardening was not all that deep or a lot of belly got removed while tillering after the fire hardening, then maybe a follow-up heat treat could be beneficial.

[Marc St Louis]

I do like DWS

[mmattockx]

I like to be brutally honest with myself. If in fact I bother to measure it, I count all set that it took from the beginning... that is, measured before any flexing begins, to freshly unstrung after shooting(within the first minute or so). So in this case, (off the caul 5" of reflex) to (after shooting 1.25" of reflex) = 3.75" of set.

So you're not in the Badger camp that considers heated in reflex that pulls out during tillering to be different than set that comes out after unstringing the bow?


Mark

[DC]

I like to be brutally honest with myself. If in fact I bother to measure it, I count all set that it took from the beginning... that is, measured before any flexing begins, to freshly unstrung after shooting(within the first minute or so). So in this case, (off the caul 5" of reflex) to (after shooting 1.25" of reflex) = 3.75" of set.

So you're not in the Badger camp that considers heated in reflex that pulls out during tillering to be different than set that comes out after unstringing the bow?


Mark

I think it "may" be different. I haven't figured a way to prove it one way or another. I think the set that slowly comes out is an indication that the wood is damaged/has high hysteresis. The shock absorber analogy fits here. The reason I kinda exclude "pullout" is that you can heat a bunch of reflex into a bow, measure it, and then give the bow a little bit of a bend. One that would in no way cause set. Then recheck the reflex and a lot of the time you will find you have less reflex. The bend has relaxed/pulled out but I have a hard time calling that set.

[Selfbowman]

I’m with Marc and DWS. If the tips touch the wall first off the caul. Measure handle to wall off the caul. Any less than that is set. Some times there is pull out . Wood just dont want to accept the heat. You will just have to experience it to know it.  Arvin

[willie]

 

[bownarra]

I’m with Marc and DWS. If the tips touch the wall first off the caul. Measure handle to wall off the caul. Any less than that is set. Some times there is pull out . Wood just dont want to accept the heat. You will just have to experience it to know it.  Arvin

And me. That is the only logical way to call it. Otherwise how do you establish a definite baseline to measure from?
Then there is 'rested reflex' and 'just unstrung' reflex. The difference between these two is interesting....but that figure is definately not total set.

[Azmdted]

Thanks all. Follow on question. For sake of discussion let’s say set is measured from straight off the caul to immediately after unstringing. In my case this bow would measure 3.75” of set. So, what would be considered good, average and poor set for a heat treated hickory bow? 

I’ve seen several references suggesting that 1” of set is good for performance and accuracy. Should my goal be 4” of reflex if it comes off the caul initially with 5?  I’m just trying to figure out what a realistic goal is as I improve my skills. Thanks again..

[PatM]

It might be worth addressing how much  you are changing the wood from its natural profile in the tree before calling things set.

[Azmdted]

Btw, this piece of hickory was from a large diameter tree as it had a fairly flat back.  It was cut about a year before I started working on it and I had it in my house for the last six months. It was flat with just a hair of propellor twist. The bow has a 4” handle, 3” fades, cut in shelf, limbs are 1 5/8” wide till the last 12” and then tapers to 1/2” tips.