# Nock indexing, spine indexing, nock tuning



## Polythermic (May 22, 2019)

As far as I understand, the ideal position of the nock can be found using many different methods, some of which are:


Float/water test:
Float a bareshaft in water, the seam/heavy side of the shaft should sink. Rotate the nock in relation to the seam.

Bareshaft paper test:
Shoot a bareshaft through paper, looking at the tear. Rotate nock until the tear is just a single hole.

Clearance test:
Spray/put powder on either arrow rest and riser, or on the vanes of the arrows. Rotate nocks and shoot until clearance problems occur. Do this again rotating the other direction to get the full range of clearance. Final nock position is approximately at the center of this range.

Nock tuning:
If noticing that one arrow always does not fly into the group, rotate nock to bring it into the group.

Which methods bring the best results? I'd imagine that the float test or bareshaft paper test would be used to get the vanes in good positions, the clearance test would only be used if having bad clearance problems, and the nock tuning test can be used to correct bad arrows. Is this accurate?


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## whiz-Oz (Jul 19, 2007)

Floating a shaft is largely a complete waste of time, but people like to do it. Hopefully their plugging method is perfectly weighted about the center point and of course, they're hoping like hell that the heaviest side IS actually stiffest. No guarantee of either. 

Bareshaft testing can be completely changed depending on if you torque the bow at all, and how far away you can be from the paper. I also know of a shooting machine that gave perfect bullet holes, but sprayed arrows on the target. So there's no guarantee there either. 

Nock tuning can bring an arrow into a group with other arrows reliably if you're using a shooting machine. Shooting machines are outstanding for testing arrow consistency. Slightly bent pins are almost impossible to correct, so you need to replace them. They'll make a perfectly straight shaft act like it's bent. Arrows that aren't actually straight enough from the factory will be incredibly hard to make group properly, so they are false economy, depending on how serious you are about being accurate. The more expensive your arrows are, the less chance you'll have of being able to detect any variation in spine as you rotate it in a spine tester. 

Clearance testing is pretty much legit in terms of checking clearance, but if you're having clearance issues, they may be more than just a spine indexing problem. Bent pins, or nock adaptors which aren't absolutely perfect (as well as arrows that aren't perfectly straight) will bias flex in one direction as the force isn't being directed down the center of the shaft any more. 
Of course, you can have all combinations of any of the known issues all happening at once. Imagine an arrow that is not straight, has a bent pin or off center nock adaptor and also has an inconsistent spine radius. All of these things exist in cheap and medium quality arrows. They show up occasionally in expensive ones too. 

I've never seen anyone bother to consider all of these at once and check for them all, but if you talk to people with enough experience, they'll have a mystery arrow that they just couldn't make work like the others.


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## Fixgenset (Mar 22, 2013)

I had a Hooter Shooter Shooting Machine. And did a lot of arrow indexing with it when I had my shop. It worked very well at culling out arrows that would not shoot in the same hole as the rest. The majority of the time I could by indexing the nock to different positions get them to shoot in the same hole at 20 yrds. But sometimes I would find an arrow that no matter what I did would not group with the rest. I would cull that arrow out and mark it as junk as there was something wrong internally in that arrow that could not be corrected.


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## whiz-Oz (Jul 19, 2007)

Fixgenset said:


> But sometimes I would find an arrow that no matter what I did would not group with the rest. I would cull that arrow out and mark it as junk as there was something wrong internally in that arrow that could not be corrected.


And... there we have someone with enough experience. I rest my case. 

However, did you ever bother to float shafts, or do spine checks once you had the hooter shooter? (or even before?)


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## dchan (Jun 29, 2004)

I doubt most recreational competitive archers would ever benefit by any of these very long testing processes. (hooter shooter maybe) 

And most of the elites that might even have a chance at benefiting from these tests, are probably getting their arrows as sponsors or as gifts. Then they just track and shoot the arrows until they have a set of arrows that group together and leave it at that. It's much faster, and more accurate and takes into account the shooter's deficiencies. 

But if you want to play, go for it. I have been there. It's pretty much a waste of time with the newer technology and materials.


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## chrstphr (Nov 23, 2005)

All of this was largely done with alluminum arrows back when the bows had less adjustments. Now with carbon arrows and the adjustability of modern takedown risers, it isnt needed and has faded away.


Chris


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## Timevoid (Aug 19, 2018)

I find this method work to find weak side of arrow, for clearence. Together with walkback tune 20-50m fletched vs bareshaft for a proper tune.
I stopped using papertune because i find it only usable for indoors. Outdoors the result sometimes apear way off. 

Starts at 5:36. 
https://youtu.be/hPnV-5XZ3i8?t=336


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## Stash (Jun 1, 2002)

chrstphr said:


> All of this was largely done with alluminum arrows back when the bows had less adjustments. Now with carbon arrows and the adjustability of modern takedown risers, it isnt needed and has faded away.
> 
> 
> Chris


Could you explain what you mean by that? I don’t understand how “adjustability of modern takedown risers” relates to checking a set of arrows so they all perform identically to each other.

I do agree with dchan and others that the process the OP described is of little practical value. The best way I have found to match arrows is to number them, shoot and plot their impact points a statistically significant number of times, and discard (or adjust and retest) the outliers.


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## erose (Aug 12, 2014)

From my experience, method of culling arrows used by Michele Frangilli. Take a dozen or two, number them, and shoot them all bareshaft at the longest distance you are comfortable shooting a bareshaft. Shoot the set multiple times and noting what arrows do not want to group with the main group of arrows. You can at this point cull those arrows from the group.

What I like to do though, since I’m a guy that believes in second chances is to turn the nock a quarter turn and give them another shot at grouping with the rest of the arrows. If they do, great. If they don’t they should be set aside.

Arrows should be shot to determine their performance. I’ve had arrows in the past that were a little lighter or heavier than the group, that hit with the group consistently; and I have had arrows that were within the group concerning their weight that shot like crap. 

IMO any of the methods outlined above are a waste of time.


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## dchan (Jun 29, 2004)

Stash said:


> Could you explain what you mean by that? I don’t understand how “adjustability of modern takedown risers” relates to checking a set of arrows so they all perform identically to each other.
> 
> I do agree with dchan and others that the process the OP described is of little practical value. The best way I have found to match arrows is to number them, shoot and plot their impact points a statistically significant number of times, and discard (or adjust and retest) the outliers.


Modern takedown bows have weight adjustment, center shot adjustment, blah Blah blah... old aluminum arrows used to mfg by curling alloy around a mandrel, and welding the edge together. This resulted in a seam that would present as a heavier and stiffer side. New modern mgf techniques as well as modern mfg of carbon products eliminates this in newer arrows.


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## Stash (Jun 1, 2002)

I’m pretty sure Easton aluminum arrows were and are extruded and drawn as tubes, no mandrel or seam involved.

Still don’t understand the relationship between riser adjustments and the arrows.


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## Polythermic (May 22, 2019)

Thanks for the insights, everyone! I won’t waste my time trying to perfect the nock position anymore.


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## Polythermic (May 22, 2019)

erose said:


> From my experience, method of culling arrows used by Michele Frangilli. Take a dozen or two, number them, and shoot them all bareshaft at the longest distance you are comfortable shooting a bareshaft. Shoot the set multiple times and noting what arrows do not want to group with the main group of arrows. You can at this point cull those arrows from the group.
> 
> What I like to do though, since I’m a guy that believes in second chances is to turn the nock a quarter turn and give them another shot at grouping with the rest of the arrows. If they do, great. If they don’t they should be set aside.
> 
> ...


Interesting, I’ll have to give this a try next time I get a new set of shafts.


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## chrstphr (Nov 23, 2005)

Stash said:


> Still don’t understand the relationship between riser adjustments and the arrows.


Having more riser adjustments can remove some variance in individual arrows and make them group better as a whole. Reducing the fliers with better tune. Most archers today generally fletch and shoot all of the dozen they buy. And generaly dont see much variance in the set overall. Though some higher level archers may find 2-3 arrows per x10 dozen are alittle off compared to the rest. 

You mileage may vary.

But its been 40 years or more since it was recommended to dump your dozen in the tun and float them for indexing. And back then it was alluminum arrows that were dunked. I dont remember anyone floating ACEs and the like. I could be wrong.

Chris


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## Stash (Jun 1, 2002)

chrstphr said:


> Having more riser adjustments can remove some variance in individual arrows and make them group better as a whole. Reducing the fliers with better tune....
> 
> But its been 40 years or more since it was recommended to dump your dozen in the tun and float them for indexing. And back then it was alluminum arrows that were dunked. I dont remember anyone floating ACEs and the like. I could be wrong.
> 
> Chris


Thanks for the explanation.

As for the floating etc, I don’t recall anyone talking about it back in the old days, and I was most active in the OLY community during the decade before carbon arrows arrived. All we did was spin arrows after each end, use dial straighteners, and check for nock wobble. 

Most of the floating/spine finding discussion I am familiar with has been much more recent, and by compound shooters with all-carbon shafts.


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## riverjunkie91 (May 5, 2019)

I don't know much about what you all are talking about. But if you wanted to find the stiff side of a shaft, you could roll test them the same way you do a fishing rod blank? 

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## swbuckmaster (Dec 20, 2005)

Imho it can be stiff side or crooked side of the arrow you want lined up. I can take my spine testing tool and find the crooked side of the arrow and line them all up. 90 percent of the arrows will then bare shaft bullet hole out of a compound bow. They will then hit the same hole out of a hooter shooter. I can also sit in front of paper with bare shafts and rotate nocks until I get each one to bullet hole then fletch. Or i can take the arrows and shoot them at 50 meters and plot their impacts, then rotate nocks to bring them into the group. All methods have been proven to me to work. I choose the first one because it's the fastest method. I then verify through paper. 


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