March 2nd, 2012, 11:07 AM
Stu Miller Spine calculator
Any one use this calculator? Interestd in how well it works before I go out and spend some money on a different one.
March 2nd, 2012, 11:27 AM
For me, it's been very accurate for calculating arrow spine from arrow to arrow, but it only got me in the ball park as far as matching an arrow to a bow. Close enough for the correct shaft recomendation, but after tuning, the length and/or tip weight may be different that what the calculator suggests.
Originally Posted by OregonBlacktail
I'd suggest you get your hand on any shaft that's in the ball park, tune it the old fashion way for proper flight and then input the numbers into the calculator to see what the dynamic spine of that arrow is. Once you find out what your ideal dynamic spine is, you can use the calculator for arrow shopping by finding a setup that gives you the same dynamic spine, but with a length, GPP and FOC that's more to your liking.
Last edited by Jeb-D.; March 2nd, 2012 at 11:29 AM.
March 2nd, 2012, 12:31 PM
The best way is to go by the arrow makers chart - and then by a single arrow from a supplier like Lancaster and test it - that will save you the most money in the long run.
March 2nd, 2012, 01:43 PM
sharpbroadhead's technique only works AIUI if one has good solid form for repeatable shots (or knows enough to tell the difference between a good and bad release).
I've found Stu Miller's arrow calculator to be spot on for me, and for those whom it doesn't match perfectly, there is a ``personal calibration factor'' option in it.
The biggest positive of using it is that it allows one to experiment w/ point weights and arrow lengths and different spines and fletchings and nock weights w/o spending money --- I went through a lot of spreadsheets before deciding on what to buy and the arrows which I selected using it are working great for me.
The worst case is it yields an arrow which is ``merely'' tunable, so be sure to get some extra points in different weights, and / or some sort of weight system.
March 2nd, 2012, 01:55 PM
ok - so if you have bad form that is not repeatable - Stu's Calculator will give you an arrow that will fly right?
Nothing replaces actual tuning - arrow makers charts and calculators do not replace actual tuning - if you don't want to actually tune - then just pick an arrow and shoot it - if you want an arrow tuned to your bow - you need to actually tune - there is no getting around that.
If you want to save money - do not trust either the calculator or the arrow makers charts - buy one or two arrows of different spines and shoot them and see how they tune to you and your bow - when you find the right arrow - then order a dozen or half dozen.
March 2nd, 2012, 02:14 PM
My experience is that the calculator gets you close but you have to tune. Still start out long and trim as you go. There is no substitute for tuning. Some bows tune well with arrows that are under or over spined according to the charts and calculator. You should still get a tunable arrow with the calculator which is what it is meant to do. Just dont live and die by the calculator
March 2nd, 2012, 06:22 PM
No, Stu Miller's charts will get you an arrow which will fly consistently enough that w/ practice and patience you'll be able to develop good enough form that you'll then be able to further tune it.
March 2nd, 2012, 07:05 PM
March 2nd, 2012, 07:14 PM
March 2nd, 2012, 07:55 PM
You HAVE to enter ACCURATE numbers, no GUESSING !
Stu gives instructions, but few seem to READ them, so enter guesses and get wrong results !!!
This is especially true of the center cut value !!!!
March 2nd, 2012, 08:10 PM
March 3rd, 2012, 07:18 AM
Since Stu Miller's DSC program came out, I no longer bare shaft tune since I get the same results as bare shaft tuning in a quarter of the time. After getting my results, I then paper tune to confirm. The calculator program has been spot on for me in choosing a 32" aluminum arrow since my arrow length is a constant. It's never longer or shorter than 32". I fine tune by adjusting brace height.
Like others have said, put in the wrong info and it won't work.
Blacktail TD Recurve: 66", 42# @ 30". BS: 12StrDyna97. BrcHt: 7 1/2". Arrow: 32", 2212. PW: 75 Grains. AW: 421 Grains. SPD: 185 fps. GPP: 10.02
Blacktail TD Recurve: 66", 37# @ 30". BS: 12StrDyna97. BrcHt: 7 5/8". Arrow: 32", 2212. PW: 75 Grains. AW: 421 Grains. SPD: 174 fps. GPP: 11.37
March 3rd, 2012, 10:35 AM
It seems to work for me with typical point weights in the 100 to 150 grain range. It is better than the charts for deciding on which arrow to buy. However, for designing EFOC arrows, it doesn't seem to to be as accurate. It could be that I'm using it wrong.
But as posted above, you have to have consistent form. Without that neither Stu's calculator nor the charts can be accurate.