stu miller

[gringol]

I'm running some numbers to get myself in the ballpark for some new carbons.  I'm shooting a 61@28 caribow slynx drawn to 29.5.  I've got gt trad 7595s full length.  Stu doesnt have the slynx, so i used the peregrine.  Stu has me 25# weak with 250 grns up front.  I've bare shafted that and it definitely isn't that weak.  I've seen stu off before, but not this much.  Anyone got an idea for this setup?

[Onehair]

I get 61 and 78 for the bow. What string and shelf are you using.

[gringol]

10 strand ff with beavertail strike plate.  Should I just ignore this calculator?

[Looper]

I would ignore it.  Settle on what arrow weight you want, then trim those shafts down to where they fly perfectly.

If I were you, I just get Arrow Dynamics Hammerheads or Trads, depending on the arrow weight you want. Just add the heads you want and go hunting. I use a full length Hammerhead out of my 64@31 r/d bows with anywhere from a 150gr to a 200 gr head and get great flight. The Hammerhead, full length, with the aluminum insert weighs right at 500 grains.

[Sharpend60]

I dont place a lot of faith in the calculator...
It has me at #115 spine, which is nearly impossible to find.

Id do your own tests and have confidence in your own conclusions.

[Onehair]

I am dead on with all of my bows. I have been 3-5 pounds off. Just for fun Bare shaft one with 175 up front and tell us the tale.

[gringol]

175 would be less than 8gpp, so I won't shoot that.  250 shoots very close.

Sounds like stu should get dumped.

[Fanto]

My slynx is 59@28

I simply can not tune 7595s. Mine are 30.5 bop and have 375 grains up front and are still stiff.

I'm using 5575s with 220 up front 29.5 bop.

I would recommend you switch to gt hunter shafts .340 spine maybe they will work at 31"

Love the slynx!!

[Rob DiStefano]

you will do yerself and yer shooting a disservice to rely upon any type of "arrow calculator" to deliver precise results.  that would be impossible.  at best, it will be a guideline of sorts.  

because of the huge difference in variables between people, shooting styles, shooting venues, bows, arrows, strings, fletchings, points, etc. etc. etc. - nothing can take the place of personal testing.

[damascusdave]

So what you are saying is that the calculator must be unusable because you will not try a lighter point weight?

DDave

[LookMomNoSights]

What is all this "Stu" stuff anyway?!    
All joking aside,  I know it works for lots of folks...and thats great.   Myself,  I just cant get into it.  I use the knowledge Ive gathered to build my arrows....start with a common sense ball park and then maybe some minor MINOR tuning to perfection.  My arrows fly perfect,  and I shoot and shoot and shoot to verify that.  I shoot 10 gpp too with no crazy FOC's.  As of yet,  never had to shoot cape buff or any massive bodied animals,  so I dont feel the need to go heavier.
I believe the HUMAN error variable has all the  weight and its easy to take that for granted and put it out of our minds.  Sure you can factor in how many hairs you have on your strike plate and so on and so on,  but a sub par release or glitch in your concentration and all the techy stuff has just been negated.
Im with Rob in regards to not puting much faith in any calculator.  This is all just my 2....and we know that dont get cha crap these days  :rolleyes:

[gringol]

I agree, Rob.  Just was trying to get in the ballpark before tuning.

[gringol]

Originally posted by damascusdave:
So what you are saying is that the calculator must be unusable because you will not try a lighter point weight?

DDave

Huh?  

I'm saying my limited tuning with these shafts to date says 250 up front is very close, but stu says I'm way under spined.

[Mint]

Stu has a personal form factor adjustment with the program that might help. I know for me the calculator has been a lifesaver when it comes to tuning carbon shafts for me. It gets me right on.

[Onehair]

Gringol, your chasing 2 different things. GPI has little to do with spine. Get the spine right (maybe 175s) and then add weight. 5/16 nylon rope adds about 80 gr per foot and no change in spine. It also packs tight in the front end and gives you that added weight up front that we like.But it's your bow, have fun.

[damascusdave]

I think if you weigh one of those arrows you will find that with a 175 grain point it will be around 575 grains and that is around 9 gpp...I think it is worth trying...another strategy you might use is calling Abe Penner and getting his take on the situation

DDave

[Friend]

Your set-up is close to 15# under as where most of my own set-ups end up.

The GT7595 value in calculator is in error.
Stu was contacted last year regarding this particular issue as well as a few others and he agreed with the findings. The new revision will incorporate these corrections.

Try some other shaft types in the equation at .300 spine and it will be clear.

[gringol]

I think I figured it out.  I was using long inserts (about two inches) which seem to be acting like a footing and adding a bit of stiffness to the shaft.  It seems backwards, but if I remove the long insert, put in a stock insert and move the excess weight to the point, the shafts start acting weak.  

It also works in the calculator.  If I set the insert weight to zero, and input the actual insert weight into the footing column, stu starts to look very close to my bareshaft results.

[Bladepeek]

There are lots of guys that say "Stu's calculator doesn't work for me", and that's fine - don't use it.

For me, it gets me in the ball park IF all the information I put in is correct. For example, I actually measure the distance before or after center rather than accept the given specs. It will get me close enough that it takes MINOR tuning to get bare shaft and fletched hitting on top of each other, or, as I prefer,  the bare shaft just SLIGHTLY weak.

Once I have tuned the arrow to the bow properly by tuning and shooting until I have the proper setup, I use the "personal form factor" to make the "answer" match actual practice. It's at this point that the calculator really becomes valuable to me. Now I can plug in different spines and point weights and juggle them in the calculator and know that if I come up with a dynamic spine the same as my proven setup, I'll be "right on" with the new arrow before I cut it.

If I have the indicated dynamic spine showing a perfect match with my indicated bow reading for a GT3555 and want to use 5575s, I can play with length and point weight until they line up with my 3555s in the calculator and by gosh - they do.

It's definitely not for everybody, but it sure works for me.

[Brock]

yep...Stu's calculator gets me close.  Once I find a shaft that works in my exact bow...then I adjust the shooter error until it works in the calculator.  Now every time I enter a bow and arrow combination that is automatically factored and has made a big difference. Your shooting style, how smooth your release might be, everything influences your shot to a degree.