# Stu Millers newest version of the Spine Calculator



## w8lon (Jun 2, 2012)

Ok, try again using link box adds stuff.

https://www.dropbox.com/s/khpsk021g8hf7kp/Dynamic Spine Calculator Rev 5-12 V2 2007.xls


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## Bob Furman (May 16, 2012)

https://www.dropbox.com/s/khpsk021g8hf7kp/Dynamic%20Spine%20Calculator%2 0Rev%205-12%20%20V2%202007.xls


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## bobnikon (Jun 10, 2012)

Do you have to have a dropbox account to access? I can't get to any of the three links posted so far.
Cheers


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## wmt3rd (Oct 20, 2004)

I get a 404 error...can't find page


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## julle (Mar 1, 2009)

https://www.dropbox.com/s/khpsk021g8hf7kp/Dynamic%20Spine%20Calculator%20Rev%205-12%20%20V2%202007.xls
There you go guys ;-)


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## wmt3rd (Oct 20, 2004)

thanks


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## w8lon (Jun 2, 2012)

Thanks Julle, Stu told me to distribute freely so thought you all ay want to play with it!
Who knows he may even be lurking here somewhere:shade:


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## LittleJP (Nov 4, 2012)

How accurate is this? It diverges from the Easton spine selector. I'm using the Lightspeed 500s for a 50# bow, picked by the Easton selector. However, it appears way too stiff when plugged in the calculator.


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## w8lon (Jun 2, 2012)

Have found it to be very accurate. Post your specs or PM me will try to run it through.


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## julle (Mar 1, 2009)

LittleJP said:


> How accurate is this? It diverges from the Easton spine selector. I'm using the Lightspeed 500s for a 50# bow, picked by the Easton selector. However, it appears way too stiff when plugged in the calculator.


This calculator seems to be aimed more at traditional type bows, they tend to be slower than an olympic bow and hence the lower spine given for a certain poundage.


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## w8lon (Jun 2, 2012)

I have been using the Hoyt Excel option myself as to bow type for an ILF should be reasonably close. Arrow manufactures just say recurve on their charts.


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## kaj4 (Mar 27, 2010)

I have to mark this one thanks


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## LittleJP (Nov 4, 2012)

julle said:


> This calculator seems to be aimed more at traditional type bows, they tend to be slower than an olympic bow and hence the lower spine given for a certain poundage.


There's the option for "performance recurve" which I assumed to be the olympic bow.

Should I be worried about spine?


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## ButchD (Nov 11, 2006)

w8lon said:


> Here is the latest version of the Spine Calculator for anyone to download! Best of all...it's free!
> 
> 
> [URL="https://www.dropbox.com/s/khpsk021g8hf7kp/Dynamic%20Spine%20Calculator%20Rev%205-12%20%20V2%202007.xls"


Thanks.
Interesting!
We'll see how it bears out. Performance factor is the wild card variable.


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## chrstphr (Nov 23, 2005)

it doesnt seem to work on my mac. perhaps this is a PC calculator. 


Chris


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## caspian (Jan 13, 2009)

it's an XLS files, which denotes an Excel spreadsheet. you'll need some sort of spreadsheet application on your Mac that can open that file format.


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## w8lon (Jun 2, 2012)

Here is the link to his earlier version. With notes regarding Mac users.
www.heilakka.com/stumiller/


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## chrstphr (Nov 23, 2005)

caspian said:


> it's an XLS files, which denotes an Excel spreadsheet. you'll need some sort of spreadsheet application on your Mac that can open that file format.


Hi,I know what an XLS file is and I have Excel on my Mac. Excel would not open the file. Hence, my post.

Chris


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## chrstphr (Nov 23, 2005)

w8lon said:


> Here is the link to his earlier version. With notes regarding Mac users.
> www.heilakka.com/stumiller/


This one works on a Mac. 


Chris


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## Warbow (Apr 18, 2006)

chrstphr said:


> This one works on a Mac.
> 
> 
> Chris


Might depend on which version of Office people are using. One relatively recent version of Office had Visual Basic removed from it. I think it is back in in the current version, but I don't know because I use Open Office/Libra Office (Open Source MS Office replacements) that didn't remove VB.


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## chrstphr (Nov 23, 2005)

then i should say, this one works on MY mac. 



Chris


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## caspian (Jan 13, 2009)

chrstphr said:


> Hi,I know what an XLS file is and I have Excel on my Mac. Excel would not open the file. Hence, my post.


then you presumably have a older/less capable version of Excel installed, because there's no such thing as a PC version of an XLS file, just the environment it gets opened in...

try either updating your copy of Office to the latest one, or better yet, the Mac to a real computer and get a PC.


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## chrstphr (Nov 23, 2005)

caspian said:


> then you presumably have a older/less capable version of Excel installed, because there's no such thing as a PC version of an XLS file, just the environment it gets opened in...
> 
> try either updating your copy of Office to the latest one, or better yet, the Mac to a real computer and get a PC.


Hi, being that i have a 2012 Macbook pro with Mountain lion OS and brand new software, I would say i have the most current version of Excel. The first file did not work. nothing more, nothing less. The second link Excel file worked. 

One would presume the file had a problem before recommending someone change their entire computer. But thanks for your input. 


Chris


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## caspian (Jan 13, 2009)

the OS has nothing to do with the version of application you are running on it. the reason the first file doesn't work is the version of application you have does not contain the required functionality to execute some of the functions required.

seriously, this is why I detest Macs. they're about 2% of the world computer market, and their owners expect total compatibility with the other 98%.


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## Warbow (Apr 18, 2006)

caspian said:


> the OS has nothing to do with the version of application you are running on it. the reason the first file doesn't work is the version of application you have does not contain the required functionality to execute some of the functions required.
> 
> seriously, this is why I detest Macs. they're about 2% of the world computer market, and their owners expect total compatibility with the other 98%.


More like 7% :wink: However, you are wrong to blame macs or mac owners. In the case of an Excel file not working on a mac one need look no further than Microsoft for crippling some mac versions of the software. That's a Microsoft issue rather than a mac or mac OS issue.

There are work arounds, including upgrading, or downgrading, to a version that isn't crippled, or using the Open Source Office replacement Open Officer or its fork Libre Office.


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## w8lon (Jun 2, 2012)

Will have to try it on my Ubuntu with Libre Office later as well as a Windows based handheld which should work as it has Excel on it. I find it handy knowing that I can make my 2311 shafts work in my Oly bow instead of buying another dozen shafts.


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## ButchD (Nov 11, 2006)

Hey W8lon,
I have a question concerning the strike plate position box.
I use a plunger, which, in a perfect world, flexes to allow the arrow to move towards the riser, approaching a true centershot.
So what would be the recommendation for the strike plate thickness?
Minor variations, yield large changes in the spine recomendation.
Thanks, Butch


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## w8lon (Jun 2, 2012)

You know Butch that is a great question. In my weak mind, not being an engineer, I would think that the flex would have little to do with the plate position being as this is the starting point of plate thickness. In a perfect world release the arrow is going to initially flex away from the riser as your point is generally tuned an arrow width away from center. The spring tension would allow for a bad release or second node of arrow flex.

It never ceases to amaze me how a properly spined arrow flexes around an Osage self bow with no cutout where you are looking at an effective plate thickness of 1/2".

There is a good set of instructions that go along with spreadsheet for measuring for the offset of plate as well.


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## ceallred (Nov 25, 2012)

Not to add to the Mac/Win discussion, but I too can't get the new version to work... The one downloaded from the website works fine on both my Mac & Ubuntu systems (using Libre Office on both). The one from the dropbox doesn't work on either of them. I'll try windows when I get to work tomorrow...

FWIW: The file opens fine, but it appears the data cell references don't work right. Once you try to select a bow model, all you get is #REF

My question is this: Is the only real difference in the data libraries? in other words; if my arrows are in the old one, is there any other reason I need the new version?









Carlton


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## w8lon (Jun 2, 2012)

Carlton, there has been a lot of information added to the newest version, more arrow choices and a nice graph display of spine as well.


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## Red01 (Sep 4, 2012)

LittleJP said:


> There's the option for "performance recurve" which I assumed to be the olympic bow.
> 
> Should I be worried about spine?


 I am hoping that this calculator does work for olympic bows under the "performance recurve" option. I find it frustrating that most of the arrow manufacturers don't list a spline that applies to the bows we shoot and the poundage some of us shoot when we are starting out when we need the advice the most.

cedrake


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## Jim18655 (Sep 17, 2011)

I'm using Open Office and the file opens but it tells me it is "Read only." I changed the file permissions to read and write for all users and it didn't make any difference. Latest version of Open Office that comes with Ubuntu 12.10. I'm by no means an expert with Linux. Any suggestion?


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## wurmz (Oct 13, 2012)

Sooo.... According to this file, I need to be shooting 1400ish on _XX75, but using the Easton Chart I need to be shooting 1716's.

My Setup:

22# @ 28" Recurve - KAP Olympic with Polaris Limbs
1716's with Easton NIBB point and 1 1/2" feathers.

I feel like I have to leave my site a little more left than I should to compensate for a fletched arrow going left. (This is just feel, no measurments.)

I'm more concerned with how far off these 2 tools are for what I should be shooting.


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## w8lon (Jun 2, 2012)

I loaded it on my latest version of Ubuntu last night and same issue with Libre Office. I am no expert on Linux myself, but at least there is no worry of a virus on the network either (kids computer).

I have been using the recurve option of Hoyt Excel instead of performance recurve. I think that you find this closer to our Oly bows. As I've said before great tool by weighting my Nibbs points with solder I have my 2311 Eclipse shafts flying like darts at 38#'s.


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## LittleJP (Nov 4, 2012)

I asked Stu regarding plungers. He suggests adding 10-15 # onto the bow, depending on the position and the stiffness of the plunger.


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## RKu (Nov 16, 2012)

Does the new version include Easton x10s? I have a Mac so I can't run the newest version. The old version is incredibly helpful but it would be nice to do some calculations for the X10s.


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## LittleJP (Nov 4, 2012)

Sadly, no. I did email him asking him to include it for the next version.


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## trevorpowdrell (May 8, 2012)

I have heard about adding 10-15lbs when using a plunger but what center cut value should be used.

Most plungers are set up to be a little +ve from center cut but that seems to give a very weak dynamic spine even after added 10-15lbs.


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## Bigjono (Apr 21, 2009)

trevorpowdrell said:


> I have heard about adding 10-15lbs when using a plunger but what center cut value should be used.
> 
> Most plungers are set up to be a little +ve from center cut but that seems to give a very weak dynamic spine even after added 10-15lbs.


What does +ve mean if you don't mind me asking, does it mean to centre or past centre?


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## Bigjono (Apr 21, 2009)

Does he have an app or version of it for an iPad?


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## ArtV (Jan 29, 2008)

Boy did this turn into p***ing contest. My computer is better than your computer.:mg: I have never found the easton charts to be wrong...only the users.:embara: A blow to Mac Arrogance, and a bottle thrown at a PC. Links that don't work..so where is the accuracy of the chart, oh darn you have to log into a special sight to find out... I remember the day you bought shafts spined 10lbs more than your bow weight and they shot great. Dynamic spin? Uhh. Soooo confusing.:wink: And now somone wants to put it on a iPad, next, iPhone, then embedded on a shaving mirror.:icon_1_lol:


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## williamskg6 (Dec 21, 2008)

Ford versus Chevy arguments aside, I am very glad to find this application. After entering my details, it confirmed what I'm seeing - my arrows are just a little too stiff and that adding some weight to the points should fix the issue. 

My wish list: I wish that the arrow selections also included arrows like the Carbon Express Medallion arrows and other skinny target arrows like the Nanos and McKinney arrows, but I think enough mainstream arrows are in there to be extremely helpful. One other thing I wish is that it would prevent you from specifying a shaft length longer than the stock length for a given arrow & spine combination. It'd be a bummer to figure out your perfect arrow, only to discover the manufacturer doesn't make it in the length you need.

Regarding an app version, It would be cool if this was an iPad / iPhone / Android application, but a mobile application would require experienced coding and a lot of time/effort. Maybe someone with those skills should offer to help spin it into an app! I know he's got a ton of time and effort into developing the formulas behind all of this, so I'm extremely grateful that he offers this up to us all!


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## w8lon (Jun 2, 2012)

I applaud Stu for putting the time and effort into this great tool, anyone for that matter shares their hard work with other archers. His spreadsheet application although not all encompassing is far more useful than the manufacturers charts. You can tweak your arrow length in 1/16" increments and see the effect. Notice the effect of strand count in your string. You can also see the effect that your footing length of your insert or glue-in point has on spine.

Does an arrow manufacture take any of this into account, no!

Carbon Express makes great shafts, but reading their charts subtracting six pounds for recurve then adding four pounds for fingers and on, and on does not help in the decision to drop $300+ on a dozen shafts. Arrow manufactures should have an interactive application such as this to help in your decision to buy their product!


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## williamskg6 (Dec 21, 2008)

w8lon said:


> I loaded it on my latest version of Ubuntu last night and same issue with Libre Office.


Just tried opening the XLS file in LibreOffice on Mint Linux 14 and it partially worked. Unfortunately, many of the macros don't work, so it doesn't provide any meaningful information you couldn't glean from manufacturer's charts. All the good stuff is in the macros.


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## w8lon (Jun 2, 2012)

There probably is a patch in Ubuntu to make it work. I just have little time to play with it myself. If I find the time this weekend will bring this up to Ubuntu support team.


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## drn (Mar 27, 2007)

Hummmm...the file can't be downloaded to my PC...windows vista home premium with office excell 2010.


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## Bob Furman (May 16, 2012)

From what I can tell this is intended for Traditional Bows, I see no options for any of the Olympic/FITA type of equipment or am I missing something? Maybe this would be better posted in the Traditional Forum??


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## andyman1970 (Apr 2, 2008)

Classic case of lower common denominator - I haven't looked deeply, but I didn't find any release notes / compatibility specs, so best case is to assume your mileage may vary. I can attest this file works fine with Windows 8 Pro / Office 2010. Kudos to the author - great little reference regardless of technology preferences. 

Bob - I think the only reference for Oly bow is the Hoyt Excel riser.


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## Bob Furman (May 16, 2012)

nor did I see any reference to Easton ACE or X10 shafts.


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## w8lon (Jun 2, 2012)

Ttt


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## w8lon (Jun 2, 2012)

Although not perfect, I still get a lot of use out of this. Thought I would pass it along again, and do have a modified DSC to run with Mac's as well, somewhere in this laptops file system.


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## adhendricks (Apr 14, 2013)

Hey I just tried the link for Stu Miller's newest version of the spine calculator posted earlier in this thread. I got a message stating the file has been deleted or moved. Any help would be appreciated in locating the new link.


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## w8lon (Jun 2, 2012)

I think that this will work, let me test
https://www.dropbox.com/s/w2ux3sbseyj25zn/Dynamic%20Spine%20Calculator%20Rev%205-12%20%202007.xls

Should work as this is latest that Stu sent me Feb 13th!


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## Mad Wally (Apr 26, 2013)

I have tried both an older version and a the new version and to my big surprise I got a very different outcome. 
For a 3-28 ACC length 31.25", 100 grain point, 11 grain insert + nock en 11 grain fletching the old program (v2) gives a dynamic spine of 61.0 and the new program (v3) gives a dynamic spine of 62.7. Any ideas anyone?


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## w8lon (Jun 2, 2012)

A Easton 3-28 ACC is showing 63 pounds static spine on my latest version. By the looks of it you are not using the footing measurement when I run your parameters. An actual measurement for footing length is critical for dynamic spine a guesstimate in this area will change the dynamic spine very much. I recently discovered how critical this was by assuming that an ACC -18's inserted footing would be 1.50" while waiting for them to arrive. Shafts were precut a little long as they were not listed,(CX Medallion .700 spine) when they arrived a measurement was taken and footing length is 1.10". This translated into cutting an additional 5/8" from shaft.

Accurate weighing of components along with length of inserted footing has always yielded accurate spine for me. I do tend to tune better with an arrow at 3/4 of the spine scale due to personal form factor or set form tab to +2 depending on performance of limbs. I find it nice to tune a bow within a few ends when switching things around, typically just spring tension in plunger +- 1/2 turn.


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