PDA

View Full Version : Stu Miller's spine calculator; review



Flying Dutchman
December 14th, 2009, 02:58 PM
Hi Gang,

today I reviewed Stu's calculator, to be found here: http://heilakka.com/stumiller/

To tell the truth: I am a man of practice. I don't like all the calculators; I want to see with my own eyes what an certain arrow does on a certain bow for a certain person. I guide some beginning archerers in finding their way in the arrow-forest and train them in shootig. I mostly make my own calculations, followed by papertuning for the beginners and bareshaft tuning for the advanced. This because beginners are not able to group properly yet. After a year or so they are ready for bareshafting too.

I did this for quite a lot of people and they always end up with the right arow.

So before I reviewed Stu's calculator, I knew already the right values for all bows involved.

I runned a 40 lbs R/D modern longbow, as well for carbon as for cedar, with a drawlenght of 29 inches for the archerer involved.
I runned a 45 lbs modern recurve, as well for carbon as for cedar, with a drawlenght of 32 inches for the archerer involved
I runned a modern recurve of 25 lbs for pine only with a drawlenght of 24 inches for the lady-archerer involved.

All bows were tested with either bareshafting either papertuning and all have a perfect arrow. I thought it was a nice mixture of different bows and parameters.

I filled the values I found in in Stu's calculator and.....

to my astonishment, Stu came pretty close! In some cases even the exact values :eek:!

Only thing is that the calculator is a bit optimistic about the speed, but what the heck!

So I would like to give Stu a big compliment for the great job he did and I would recommend this calculator as a very good starting point for which arrow you need!

I specific mention this, because in a earlier topic I was a bit hash on the calculator. Sorry Stu!

innate123
December 14th, 2009, 11:04 PM
Mr. Dutchman:

Very nice review of the calculator. I will be beginning my voyage into Trad hunting after Xmas. I bought my son and myself some inexpensive Samick Sage 45 lb. T/D recurves.

I am only interested in killing deer with this bow and assume if things go right will some day settle in that 55 lb range bow.

My question is this as I have not gone very far down the trad. path is this...What are your beliefs on FOC for hunting. When using Stu's calculator, you can plug in different values for nock weight, inserts, tips etc. Changing any or all of those values can change which arrow one could choose.

If I am just starting and keeping in mind I only want to be able to hunt (no 3d or target shooting) should I spend more time with messing with the weight up front of the arrow?

I do not have the bows set up yet, but my compound draw is 29" so I'm guessing I'll be around 28" for a recurve. I think the Samick Sage is cut right in the middle of the riser so I am unsure whether or not I should shoot off of the shelf - I hope I can. And, I'll be using DF97 strings.

Just looking for an experienced opinion of what arrows and tip weights I should be looking at.

t

Flying Dutchman
December 15th, 2009, 02:44 AM
First off all: Stu's calculator is a great starting point, but not more then that! However, it will probably save you a lot of time when you start to tune your arrows for real!

My believes for FOC for hunting is that it must be something higher as we use for 3D, where I use 8 to 12%. Somewhere between 10 and 15% for hunting will be allright. But there are lots of hunters who don't care for FOC at all! As a broadhead on my GT 15-35 Traditional Hunter I a use a Magnus 4-blade which gives me a FOC of almost 15%.
Most important thing is to remember that you develop the right arrow for your kind of bow and Stu's calculator gives a pretty good starting point. Don't use to much gimmicks: a standard nock and insert will do just fine. Use the point weight to tune the arrow in Stu's calculator. 100 and 125 tip weights are quite common. When you found a combination in which the difference is less then 2 lbs, it's time to start tuning for real with this arrow.

You can use either papertuning or bareshafting. I prefer bareshafting but you have to be more experienced for this. Papertuning can be used for starting archerers.

You can find a comprehensive link here: http://www.goldtip.com/bowtuning.htm

If you have more questions: shoot!

alanraw
December 15th, 2009, 05:51 AM
When attempting to find the correct spine, Pete Ward's deflection chart is excellent! You could also ask Viper1---I've gone to him on numerous occasions for spine advice---he's never off

Flying Dutchman
December 15th, 2009, 09:28 AM
I can't find Pete Ward's deflection chart, do you have a link?

Viper1
December 15th, 2009, 10:31 AM
FD -

The Easton site has defection ratings for their arrows as do all the other arrow manufacturers. The trick is to translate the static deflection to draw weight pounds. (Easton apparently forgot how to do that in the 80's ...) A little quick number fudging and you can use the deflections to your advantage.

You are correct that ANY arrow chart is ONLY a starting point. Fact is this stuff ain't rocket science.

Alan -

A reason that some "charts" seem to work is because most arrows have about a 10# spine to weight tolerance, which is well within tuning parameters - AND THAT'S ALL YOU NEED! The same holds true for the recommendations I make, The only difference is - I admit it :eek:

Unfortunately, there are a lot of people today who are more comfortable plugging numbers into programs, rather than understand a couple of basic principles.

This strikes a bit of a cord with me, as the things that some folks worry about today (arrow weight, FOC, even speed, etc) is so minor compared to basic shooting skills that it really doesn't appear on the radar. I don't recall a lot of arrows bouncing off deer before we knew or cared what FOC was.

Viper1 out.

innate123
December 15th, 2009, 11:00 AM
FD - thanks for the reply.

Viper - Any starting point suggestions on your side? As stated earlier, I'm pretty clueless at the moment as I had started with compound/release/peep/sights from day one and really was naive to "tuning" a recurve.

I have always brought my compound into the shop and had the owner tune it and had good results. I'm hoping that I remember the bow shop owner telling me he used to shoot trad, but I'm not sure.

I really thought arrow selection would be less critical with a trad bow than with a compound prior to starting to read the threads here and on trad gang.

I agree with you that shooting skills is number one and that proper arrows will only go so far if a guy doesn't learn how to shoot correctly.

I don't have bow strung up yet as Lancaster sent me B50 instead of DF97 for my Samick Sage. Pete Ward (I hope he's credible - sure sounded that way) in his review said the DF97 strings made the bow perform significantly better for a beginner.

My regular draw is 29" so I am assuming that I'll be around a 28" draw and the Samick is 45# draw weight and I think the shelf is pretty close to center cut. My son will have the same bow but likely a 25" to 26" draw.

Thanks for the replies so far and any others would be appreciated.

t

innate123
December 15th, 2009, 11:27 AM
If I use the calculator using a 29" easton epic 600 with a 125 gr broadhead with a 14 gr insert (is this standard?) and 11 gr nock (standard?) and 5" arrows - I get a I get a 53.6 dynamic spine rating

Using the Samick Sage, 45# at 28" with a 28" draw, DF97 strings, shelf centercut at 0"(I'll check it on my riser to make sure) I get a 54.1 dynamic spine rating.

By what Stu says, that is a pretty close match. HOWEVER, I see alot of guys saying you need 10 grains per pound of draw which would put me at 450 grains total. Stu's calculator has me at 345 grains total.

But, I like the idea of the speed he is talking about although someone stated in another thread that his speeds are overly optimistic.

If I go heavier, will a bow be easier to shoot?

Again, I am only interested in killing deer and being very proficient at it. It will be a great accomplishment in my mind killing a deer with a trad bow set up as I have known nothing but trophy hunting with a compound.

Thanks again for any input.

t

innate123
December 15th, 2009, 11:37 AM
sorry for all of the posts, but the riser is now -1/16th as I measure it per Stu's directions

t

Viper1
December 15th, 2009, 11:39 AM
t -

There's nothing wrong with using a B-50 (Dacron) string on a FF type (D97) capable bow. Only down side is that some newer limbs MAY vibrate a little more with B-50, however much of that can be tuned out.

As far as recommendations, this is a ballpark starting point, but seems to work well in most cases ;).

http://www.shootingthestickbow.com/rich_text_3.html

Will this give you the "perfect" arrow 100% of the time? Seriously doubt it - but as I said, it will get you close enough to tune and that's what you're looking for.

Sorry, can't help ya much with carbons, except that the same basic principles apply.

Regard things like FOC, I believe it stands for Frickin' Over Complicated and arrow weight isn't really an issue as long as the weight is considered safe for the bow in question. Most bows should be able to handle 8 gr/lb (8-10 is about the norm), newer hi-perf can go as low as 7 gr/lb.

Regarding the Samick, it ain't the fastest horse in the barn, but still a nice shooter. Because you don't know your draw length with it as yet, a 30" 1916 would be safe. Your son might get away with them for now, but as he develops, he'll fall into 1716 - 1816 territory (probably the 1816s will be closest), again depending on arrow length.

Hope that helped.

Viper1 out.

innate123
December 15th, 2009, 12:05 PM
Viper:

Are you recommending aluminums over the carbons? I just assumed carbons would be a bit faster out of a lower poundage bow, but if performance is an issue - i.e. aluminum flys better, it would be good to know. I just know I liked carbons with the compound.

Thanks,

Tim

Viper1
December 15th, 2009, 12:22 PM
Tim -

Carbons aren't always lighter than aluminum and that's the major factor in regards to speed. (Carbons do recover faster from paradox, but in my experience, it's not enough of a factor to be concerned with.)

I've always found aluminums easier to work with and the more you get into tuning, the more choices you have (diameters, weight, etc.)

On the durability side, I've seen as many carbons as aluminums in my old range's "dead arrow" drawer, so I have to call that a wash, however YMMV.

Anywho, the choice is more one of preference than reality, so go with your gut on that one.

Viper1 out.

innate123
December 15th, 2009, 12:38 PM
Viper:

How is that book you referenced in the link? I have someone sending me the Traditional Bowhunters Handbook to look at for as long as I need. I'm not a voracious reader (would rather watch dvd than read unfortunately) so I don't want to get too overloaded with info.

Thanks again for the quick responses,

t

Viper1
December 15th, 2009, 01:01 PM
Tim -

I think that book is pretty decent :)

Viper1 out.

Flying Dutchman
December 15th, 2009, 01:05 PM
Tim,

when you get started, arrow tuning seems the most complicated invention on this planet. When you start to play in practice with it however, you will see all the logica behind it... and then it is even fun trying to tune the arrow at its best.
Like Viper said: FOC is not important, certainly not for hunting, where distances are short. If you can stay in the range, there is no reason why you shouldn't, but when you can't no need to worry about it.
For carbon I have very good experiences with Goldtip Traditional arrows, but there are plenty others.
Remember: the proof of the pudding is in the eating! So get yourself some arrows and start tuning and shooting:wink:

And tell us what you found out! :wink:

Sorno
December 15th, 2009, 03:38 PM
Viper:

How is that book you referenced in the link? I have someone sending me the Traditional Bowhunters Handbook to look at for as long as I need. I'm not a voracious reader (would rather watch dvd than read unfortunately) so I don't want to get too overloaded with info.

Thanks again for the quick responses,

t
Viper's being all together too modest here...

The book is fantastic. I wish I had read it before I started shooting a stick bow in July. I have had to 'unlearn' a few things, but by and large (entirely by luck) stumbled along a pretty similar path. I will never be a great stickbow shooter, but I will likely attain the degree of proficiency that I desire by digesting the material in the book. I've gone over most of it twice and some of it 3 times and continue to apply tidbits previously missed.
Having come from a world of smallbore position shooting, I garnered enough similarities to make the learning curve tolerable (I have no access to a coach here). The book reads well, follows a logical sequence and is adequately illustrated in support of the text. I, as a new stickbow shooter highly recommend it.
S.

lazy ike
December 15th, 2009, 04:01 PM
Viper.....Are you going to tell him?:wink:

innate123
December 15th, 2009, 05:43 PM
LOL - I am getting the impression that Viper is the author? My bad, again proving my "newbie-ness" to the traditional world.

Does that mean I can get an autographed copy?

t

innate123
December 15th, 2009, 05:45 PM
Thanks again for the replies Sorno, FD, and Viper. Yes, the tuning "stuff" is scaring the crap out of me!

t

Viper1
December 15th, 2009, 06:57 PM
Tim -

Before you even worry about tuning, get your shooting from down first, other wise it can be frustrating.

Once your form becomes reproducible and you understand what's going on behind the tuning process, it's really easy to do. Yes, part of the tricky is getting the arrows pretty close to what you need in the first place.

LOL, I was going to let you spin on the book thing a little longer. Yeah, guilty as charged.

Viper1 out.

innate123
December 15th, 2009, 10:30 PM
Ya I'll grab some arrows after the holiday and start shooting. I'll check the book out. It got very nice reviews from the Amazon crowd. I think I saw an online version of it, I may try that.

t