Dryad static recurve ILF limbs and riser

[wingnut]

WE are still playing with the limb angle on the riser but we do know that limbs are weighing pretty close to the "standard" with it.  I have a couple of Rusty's Morrison risers here that are +8-10# with the same limbs.

Mike

[Bender]

Serious question here.
 Wingnut said, "The arrow weighed 489 and shot 171. When you normallize it comes out to 200 fps."
 What does "normallize" mean?

[wingnut]

Bender,


I have a program that adjusts to the 9gpp standard.  I call it normalizing.

Mike

[Bender]

So 489 grains @ 171 FPS = 31.7 ft-lbs KE Is "normalizing" when you then take that KE figure and work the equation backwards, substituting the 9gpp arrow mass of 360 grains? Because that does yield V=199.1 FPS.
 But isn't that rather confusing because we already know that the 9gpp arrow does 194 FPS not 200?
 We know that efficiency increases as arrow mass goes up, so wouldn't it be more straightforward to just compare the KE and/or momentum figures of the 2 different arrows?

[HATCHCHASER]

I bet them babies are quiet.  Looks good guys.

[wingnut]

Bender,

You answered your own question, we know that efficiency goes up with arrow mass.  But how much?  By shooting a heavy arrow and then running the program, I can predict the amount of increase.

It works best when you see someone post 5 bows of different weights shooting the same arrow and comparing fps.  By normalizing you can get a apple to apple comparison of the results.

My only concern with the light arrow used in this test is that the spine was very light and it may have not been flying as good as we would have liked.  Good arrow flight is very important to testing.

Mike

[Bender]

Sorry doesn't work that way. The 9gpp arrow did 194, not 200. 194 ain't bad, No nead to purposefully throw out confusing numbers to make things look better than they really are. If there was problem with tuning then that should have been addressed first, prior to generating the test. That computer program isn't going to "fix" tuning. To generate KE with the higher efficiency of the heavier arrow then work the equation backwards to pretend that the bow is just as efficient with lighter arrow is misleading.  It would seem "nomalizing" is a pointless exercise.

[wingnut]

You are intitled to your opinion.

I find it helpful in seeing the performance across the spectrum of arrow weights. And very helpfull with folks doing their own testing with heavy or light arrows.  Being able to predict results is a good thing.  If you follow up with actual testing.

Now if I had just done the heavy arrow and touted that as the number for 9 gpp that would not have been right.

Mike

[Lenny Stankowitz]

This is not to start an argument at all but I'm honestly a little confused.

Based on your your results, we know what 9gpp will do and we know what the heavier arrow will do...they were actually tested.  What good is a computer program that gives you incorrect information?  How does "normalizing" turn 194 fps into 200 fps?

I'd like a computer program like that to balance my checkbook.  

[Bender]

Lenny, normalizing turns 194 into 200 by using the efficiency generated by using a heavier arrow to calculate backwards and generate a velocity for the lighter arrow as if it were just as efficient as the heavier arrow. Which it never was or ever will be.
 You're missing out on something very important here that Wingnut told me. The belief that 194 FPS isn't really 200 FPS is just an opinion.

[Lenny Stankowitz]

Thanks Bender but you lost me right about here...

 

Originally posted by Bender:
Lenny, normalizing turns 194 into 200 by using the efficiency generated...

:confused:  

Don't feel bad though, I confuse easily.

[wingnut]

Gentelmen,

You need to get out and shoot or something. Your spending way too much time playing with the computer.

I have a program that I wrote a few years ago that can take information from shooting bows and normalize it to the standard of 9 gpp so that you can compare apples too apples.

In this case we shot the heavy arrow and ran the program.   The number was too high in my opinion.  So we went through our arrows and found a .600 carbon and built it up to hit the weight exactly.  When we shot it the speed was 194.

So I turned an estimated 200 into an actual 194.  I shared the heavy arrow results 171 fps because the bow gained more then expected efficiency jumping in arrow weight.

But please if you want an explaination give me a call or stop by my booth at a show.  I'd be glad to get into the finer points of mathmatics and physics with you.

Mike

[trashwood]

well I am glade that NASA has good "Opinions".  hit a docking ring of a space stations with a shuttle must take REAL good opinons.  Much less Mars from earth......well come to think of it maybe math is a little more than an opinion  

rusty

[monkeyball]

I think I am going to go string my self-bow up and get my head clear..........

                             Craig

[Bender]

Nice save, but it isn't what you originally implied.
 And do even begin to presume that you are in a position to teach me anything about math or physics.

[Lenny Stankowitz]

Originally posted by wingnut:
Gentelmen,

You need to get out and shoot or something. Your spending way too much time playing with the computer.

Mike

Yeah, you're probably right.  

Hey wait...you posted twice as much as I did on this thread.   :confused:      

 

[Tom Leemans]

Dang Mike! You losin' weight?

[wingnut]

Yep Tom lost 65# in the last couple years.  Trying to get down to my college wrestling body.

Well that's not going to happen but I would be happy to hit 230# before I turn 60.

LOL

Mike

[dick sable]

Those limbs look beautiful - - put that darn seed in my brain and now I can't get it out of there. Boy, at 56" and about 58#!! Maybe I can make space on the wall, eventually. Gotta let it germinate a bit!