Stu Miller and carbon shafts

[Flying Dutchman]

Hi,

I am working on a new set-up with carbon shafts. I use Stu Miller as a starting point. I remember some threads about the outcome from Stu with carbon shafts was to stiff, so over spined. But I can't remember exactly and am not sure about that. I can't find the threads also.

Some people can help me along with that? Are you overspined when using Stu for carbon shafts?

[Bowwild]

My outcomes with Stu's calculator are always right on.

[Rob W.]

I almost always end up 10# lower on dynamic spine. I base everything on generic values for LB or RC and measure strike plates myself.

[LittleBen]

Just used Stu calcukatir today and it was spot on for my 62" hickory selfbow

When using it for other peoples arrows, I have found that there are a few bows in the list that are exagerated in performance and arrow tolerances.  I have also found that the generic bows are very close for spines, but the fps may be different.

[xtrema312]

10-12 bows of all kinds some listed and some not.  All showed stiff with carbon arrows at the listed recommendations.  10-15# under listed recommendations usually work best for me currently.  

I have found that lighter spine shafts with lighter points are closer to listed calculator numbers.  They also bare shaft a lot better and more consistent with obvious chanes in flight with slight changes to point weight and length.  Stiffer spines with HFOC tend to be the ones needing to be weaker than listed.  I see the same with shafts a lot longer than just 1” past my draw length.  Something about the way a carbon reacts.  

I have about a 29” draw and shoot around 50-55# at that draw length.  With 500 spine shafts I often get around 10# weak per calculator and that looks about right with the why they fly, but I can’t cut more or go lighter on the point due to gpp getting two low or shaft being too short.  When I jump up to 400 spine shafts, I find them to be much stiffer and that is when I get 10-15 pounds under listed calculator numbers to get tuned.

I have also found that different shafts of the same or close listed spine do not fly at all the same when set up per calculator.  Even small differences in spine make a big difference in the way they fly.  I get a wider range of difference in bare shaft flight between Beman 500, GT 3555, and CX 150’s.  Way more variation than the calculator lists and what you would think based on manufacture listed spines for these shafts.

Adding up all the little variance from experiences I have found in things has led me to always start about 20# under the listed calculator numbers to start my tuning with a 400 spine shaft and about 10# under with a 500 spine.  From there I bare shaft or paper tune to get dialed in.

[Will Cocke 2]

Stu always shows stiff for me.  Usually 10 -15 lbs dynamic

[tj69]

Stu Miller works great for me. Perfect tool for carbon arrow tuning.
Dont forget the personal form factor......

[TxAg]

My current combo matches up perfectly in stu's

I've had other combos that showed weak.

Great tool as far as I'm concerned

[Friend]

Last five different bows set-up with different arrow designs have tuned well at slightly over a 15# underspined average.

[Flying Dutchman]

Any more?

[nineworlds9]

Yup it calculated too stiff for me too

[Biggamefish]

I just put it in for my new bow that I am getting and switching to carbons with that bow.  It says it matches perfectly we shall see when we get the bow.  Bow spec are a 50# @ 29" RD arrows are TD5575 arrow 165 point with a 100 grain insert 3 5" feathers.

[Rob DiStefano]

if you think about it, it would take an impossibly enormous and complex amount of code to be able to take into account all of the myriad of variables - perhaps into the millions - between the seemingly simple bow, arrow and archer.

which is why such "shaft/arrow selection" software is typically fair to middling at best, and can never ever be relied on to work very well even most of the time.

if you were to ask 20 archers to be very specific about how the calculator worked for them for the parameters they entered, you would at least get 20 very slightly different to wildly different answers.  getting their opinions will be just that - their opinions of how they manipulated the software to work for them, not you.  particularly software that has built in "fudge factors".

if you need assistance with stu's shaft/arrow calculator, please take your questions to stu and not trad gang.  we will all be better served by that, and thank you.

[Bowwild]

I've used Stu's calculator for my son and I for 3 years . One of the best "finds" on trad gang for me!

[threeunder]

Agreed.  I'm a firm believer in it.  Always been spot on for me.
Ken

[Flying Dutchman]

Okay, I bareshafted till 20 yards and shot perfect groups. Then I compared the arrow set-up with the results in Stu's calculator.

Stu was spot-on.

[yeager]

Just finished a set of FMJ's for my RER LX using Stu's calculator and they fly absolutely great.

[Nativestranger]

I will say Stu DCS is pretty accurate most of the time.  But it has some trouble with very light or very heavy point weight on carbon arrows as well as risers that are well before center cut. Just earlier today I got to shoot my bare shaft full length GT 1535 trad from a 38# hill longbow with a regular arrow shelf. According to dcs it should require more spine than my bow at 43# with a 0.35" before center riser. It shot the bare shaft waaay stiff while mine shot weak.