Request for those who are starting a new bow.

[Badger]

You dropped weight to get 28".  He just drew his farther.

  The test does work out better if you don't have to drop weight but if the formula is right on it shouldn't matter. I have my doubts about the accuracy of the formula although I do know it is close.

[BowEd]

Good post leonwood.Shows what freshness in a bow is like with the pursuit of good tillering and design in mind.Nice bow and good work on that one.With minimal set like that on self bows I make here they usually will hold that speed @ 28" after being broken in.Not trying to take away your thunder here because that is a very nice bow and would be proud to have made it but occasionally I will have one that shoots into the lower 180's @ 28".Not near all of them but into the mid 170's usually.One or two I know still shoot the lower 180's after a hunting season and a summer of 3D season with well over 2000 arrows through them.One of them did'nt get any heat treatment.No deflex in the handles though.
Would of liked to test those bows fresh @ 24".Made a bow from the other half but with a rounded belly and it shot in the mid to upper 170's.

[Badger]

  Ed, I think any bow hitting up near or at the 180 range is not going to show much difference at the fresh 24" or the finished 28". It is pretty common to see bows fresh at 24" hitting at 180 and then fall back to low 170's after hitting 28".

[BowEd]

Your probably right.I'd have to see it for myself through my own testing though.

[Badger]

  It would be somewhat dependent on the design as well. A very aggressive design might be capable of 190 fps when perfectly executed but because of the high stress nature of the design reaching full draw without set is a lot more challenging. In a case like this you might see a bow hitting close to 190 at 24 then dropping off to 180. But in bows with more basic designs and just a little reflex hitting about 180 is excellent and not much more can be expected.

[BowEd]

I'd have to agree with you about that.The bows I speak of have flipped tips with barely 3" of set back of tips.With not near perfect wood in them.Knots and wiggles very evident.They are eye opening that's for sure especially after going through longer time consuming efforts with other bows only gaining 10 to 15 fps results.

[leonwood]

   Leon, that looked like a good test, you did a very good job on that bow! That is only a very small loss. I appreciate you doing this!

 I am hoping to keep this thread going for a while and get more guys to feed in some numbers. Don't be embarrassed if you don''t match Leons numbers. I would be tickled pink to get numbers like that. We need the good bad and the ugly here, it helps all of us.

Thanks Steve!, this bow was designed for low stress and not for raw speed. I want to shoot the summer 3d competitions with this one. Just for fun I shot my bl hld static (63@26) with the same 24 inch arrow and got 195 fps, has nothing to do with the test but was just curious
I did make an easy setup for my chrono sowill start using it more often now.

And on my next bows I will repeat this test and post results here

[BowEd]

Bows I'm speaking of are low stress bows.Reason why they stay the way they are.

[Badger]

 I agree Ed, I have had the best luck with conservative designs. I think low set and low stress trumps most everything else.

[BowEd]

Myself with wood bows I'd rather not use any heat at all on these bows.Just a thing I have about heat weakening wood sometimes.Not always of course and type of wood heat treated considered too.Just flipping the tips some and working with naturally slightly reflexed bows.Seems to me most times those hold up the best.

[DC]

If I'm getting this right Leon didn't do any tillering between the tests, he just changed arrow sizes. I took a lot of wood off between tests 1 and 2. Surely this would skew the results. Jump on me if I'm wrong.

[willie]

Don,

I agree that the way the tests were done (yours and Leons) are not the same, but as badger suggests, perhaps the results are similar.? It would be nice to clarify which way the experiment is to be run if results are to be compared.


a few thoughts.....

1. if the bow is tillered to your weight goal at 24, then just drawn out further without removing more wood, then you are being asked violate the "never pull harder than your weight goal" principle.  Leon just happened to be at 45@24 even though his weight goal for the finished bow was 50@28. Other folks might be 50@24 if tillering a the more usual way, putting the bow closer to 60@28 when "just drawn out". Perhaps not the best pratice for a low set bow intended to finish at 50@28?

2. if wood is removed between the first test @24 and the test @28, then the second test @24 is done with less wood than the first test @24.
would this second test @24 be all that useful? apples oranges etc.

3. Does one have to make three arrows all at 10GPP, or can an arrow that's "close enough"  be used and kinetic energy be calculated from  1/2 MVV to make the comparisions,?

Steve, do you have a quickie way to make test arrows of various weights? aluminum with inserts or something similar?

[Bayou Ben]

Leonwood, were you using some sort of shooting machine?  I'm trying to figure out what's the best way to shoot right at 24" draw.  It seems it would be hard to get consistent results trying to eye a mark on the arrow. 
I don't want to build a shooting machine.  I would rather spend that time building another bow 

[Badger]

  Ben, no substitute for a shooting machine but you can get very good and accurate shooting over a chrono by hand if you practice enough.

Don & Willie, not taking wood off does give a superior read out for the test results but most tests will be taken removing wood to avoid going over. This method relies more on a good formula. I believe that Leon used Woodbears formula, my formula based on string travel uses slightly lighter arrows. I think the true formula might be somewhere inbetween the two but closer to Wood bears. Once the bows have been draw all the way out the numbers at 24" and 28" should match if the formula is good. Leons pretty well match within 1 fps. I would rather see the 1 fps on the faster side than the lower side as we know we pick up just a tad more hysteresis drawing it further but over all the formula looks pretty good. Avoiding dramatic differences is what we are mostly looking for using an imperfect formula. 

[willie]

Steve,

woodbears "formula" give a slightly different arrow weight than your "formula" for an arrow weight to conduct the test with.  But isn't kinetic energy what we are after here? Easily calculated from either weight arrow, or even a slightly different weight arrow?