# Centershot Tuning Explanation



## TXHillCountry (May 9, 2003)

I have read the Easton tuning guide multiple times and I just don't understand the recommendation on centershot. It says that when paper tuning if you get a left tear that you need to move the rest to the right. This seems to be opposite of what you would need to do. Seems like to me a left tear would indicate the arrow is coming out of the bow with the point too far to the right already. Can someone help me with this?


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## nuts&bolts (Mar 25, 2005)

*Paper tuning for arrow contact, spine issues - walkback tuning for centershot*

aboyer:

Paper tuning will give you a "Polaroid picture snapshot" of what the arrow was doing at the particular distance you decided to paper test an arrow. I have a DVD of extremely slow motion video capture of several pro archers. All arrows will oscillate to some degree when fired from a compound bow.

I think of setting centershot, sight windage and nock point position as "gross tuning". You need to get in the ball park, before going on to fine tuning.

Center shot and windage are related and walk back tuning is the best way to set these two parameters.

But first, fire a bare shaft at a target bale at the range and adjust nock point until the bareshaft sticks in the straw bale level. If the tail is high, lower the nock point, and if the tail is low, raise the nock point.

For walkback tuning, hang a weighted string from a straw bale. Place a piece of duct tape or a sticker on the target face so that the string splits the sticker in half.

Walk back 20 yds from the target in a straight line, and using your 20-yd pin, fire at the sticker. Don't worry about where the arrow hits. Step back in a straight line to 30-yds and use your 20-yd pin, fire at the same sticker. Repeat at 35 yds and 40 yds.

If your arrows look like this pattern "/", move your arrow rest 1/16th inch to the right. Don't touch your sight pins. Go back to 20-yds, aim at the sticker, and fire again. Step back to 30 yds, 35 yds and 40 yds and fire at each distance using the same 20-yd pin on your sight. Keep adjusting your center shot on your arrow rest, until the arrow pattern looks like this "|".

Now, the arrows that finally look like this "|", may be straight up and down, but they may be several inches left of the weighted string. Now, we adjust windage. Don't touch the arrow rest. If the arrows are in a straight line up and down, but are several inches left of the weighted string, adjust the windage on your sight until all the arrows are straight up and down and hitting the weighted string. 

Now, windage and centershot are perfect.

If after all this, you still have energy, you can paper test your arrows.

If you get any tears, it will be because your arrows are not a match spine wise to the draw weight of the bow. You can play with draw weight up or down to try for that elusive bullet hole.

The other option is to buy OnTarget2! from Pinwheel Software, an AT Sponsor.

You can keep the bow at your favorite draw weight, and then find a friend with an arrow saw and you can either cut the arrow shaft to make it fly stiffer if need be, and/or customize the weight of your target tips to get the spine just right.


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## KDS (Oct 11, 2005)

Copied and saved!!!!! nuts&bolts great reply to a good question :beer:


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## Bees (Jan 28, 2003)

nuts and bolts? would I be correct in thinking that paper tuning is more of an indication of spine, rather than center shot?


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## karday (Aug 20, 2002)

*Bow tuning*

Love these discussions because no matter how long you have been at it it shows we can always learn something. I paper tune as a ball park reference to basic nock height. I use the rest to get either a bullet hole or even a slightly high left. Not extreme but it satisfies my technoarcher brain that the arrow is moving away from the primary contact area. I then use foot powder to verify I am not getting contact. My walk back I do with 3/4" black tape (or a wide black marker line) on the back of a paper target. I then shoot at the verticle line and adjust sight windage to get the arrows hitting on the tape and then do the same with the horizontal line. If you can put arrows on the tape from 35-40 yards then any misses you have in a shoot you can be reasonably sure is the result of human error. According to the manufacturers the ultimate goal is to get the arrow to follow the path of the string. Most any bow today will do that. The one sure thing is that the bow will reproduce the same "error" over and over. The human will not! Since we humans hate accepting blame for anything it is in our nature to blame a less than perfect result on something else. In archery it is our equipment. You have heard that anything new you add will increase your scores .....for about 3 days. Sort of adds credence to the mind part of archery. Too many times we spend too manyhours tweaking our equipment because it has got to be the cause of a less than perfect score. Get the gear in a good basic tune and and spend time learning how to make a repeatable shot. If you have a gross paper tear that nothing corrects than it is likely an arrow issue. Most experts will agree that if you error in your choice of arrows then make that error more stiff than weak. Olympic archers spend infinitely more time tuning arrows than bows. Fortunatel for us that shoot with releases off of a loop we have much fewer issues to tune to than a finger shooter dealing with arrow nodes.


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## lefteye (Oct 24, 2005)

*nuts&bolts Q?*

Great explanation, but I have a couple of questions. 

1. Do you set nocking point shooting bare shafts at different distances? If so, what distances?

2. Do you shoot bare shafts or fletched arrows at 20 yards, etc., in your walkback tuning method?

3. Do you make your initial windage adjustments on your sight shooting bare shafts or fletched arrows?


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## nuts&bolts (Mar 25, 2005)

*Get center shot and windage correct first, then paper tune*



Bees said:


> nuts and bolts? would I be correct in thinking that paper tuning is more of an indication of spine, rather than center shot?


If you use walkback tuning to get centershot and windage correct first with fletched shafts, and you also got the nocking point correct with a bareshaft, then the paper tune will tell you about arrow contact with the bow/rest and if you might also have a arrow spine (stiffness problem).

Fire a bareshaft at a target, takes away any steering corrections that the fletching is making. A bareshaft at short distances (say 10 ft in the garage) will find gross problems with nock point position. 

A bareshaft at longer distances (10 yds at the range) will allow fine tuning for nock position. The goal is level arrow flight.


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## Deezlin (Feb 5, 2004)

*Great tip!!*

I had thought about just walking back. I had away shot and then move and the shot again until I had them all lining up at different yardages. It was a lot of work doing it my way. Your way is so much simpler.


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## nuts&bolts (Mar 25, 2005)

*A few suggestions*



lefteye said:


> Great explanation, but I have a couple of questions.
> 
> 1. Do you set nocking point shooting bare shafts at different distances? If so, what distances?
> 
> ...


lefteye:

1. The goal is to get the arrow flying level when it leaves the bow at launch. A bareshaft has zero correction because it has no fletching to provide correction. You can get a rough idea for nock point position in your garage by firing 10 feet. I fire at a cardboard box with lots of cardboard so I get an accurate idea of the angle of flight. If you have a foam target, that works too. A bag target may give you erroroneous information about the angle of arrow flight.

So, fire into a cardboard box with cardboard and several inches of newspaper. Measure the angle of the bare shaft arrow in the target with a carpenter's level. Adjust your nocking point until the arrow is perfectly level in the carboard/newspaper target.

2. Walkback tuning is for a fletched shaft, after you are satisfied with the nock point position. You need to fire the arrow at distances where you are comfortable you can group well. Pick at least three or four distances, sufficiently long enough that the arrow will drop. A properly tuned bow will hit all arrows in a vertical line.

Once the arrows are nailing the target in a vertical line, then adjust windage accordingly.

When walkback tuning is complete, and you have a clean release with good followthrough, you should have very few left-right misses. All you need to do now is to sight in your pins and you will be nailing x-rings!

3. Setting windage is part two of walkback tuning. Don't touch the windage when your fire your first arrow at the 20-yd target with the weighted string. Aim at the sticker or piece of tape underneath the weighted string. Don't worry if the arrow misses the string left or right. 

Just make sure that your keep the sight ring centered in your peep sight and that you are holding steady with your 20-yd pin at the sticker or piece of tape under the string.

When your fire the next arrow at 30 yds, don't touch the windage, center your sight ring in the peep, hold your 20-yd pin (same pin) on that sticker or piece of tape, and fire away. Don't worry about a left or right miss. You will fix that later.

Fire another arrow at 40 yds, etc, etc. Look at the pattern. If your last arrow is low and left of the first arrow, move your arrow rest 1/16th inch to the right.

When all of your arrows are hitting the target in a straight vertical line, then adjust your windage so that all of your arrows nail the weighted string.

All of walkback tuning is performed with a fletched shaft.

PS: One more thing. You did check your 2nd axis before you tried walkback tuning?


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## JAVI (Jun 19, 2003)

When bareshaft tuning.... make sure the target is at shoulder level....


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## capt ace (Nov 11, 2005)

Whats wrong with sighting in your 20 pin before you walk back as long as you don't touch it while your walking back? In other words why can't you sight your twenty yard pin in first at twenty yards to hit the aiming mark and then do your walk back tuning?


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## Deezlin (Feb 5, 2004)

*Horizontal Tuning*

We have explained the vertical aspect, how about the horizontal.

I usually shoot at twenty yards at a horizontal line. If I am getting some up and downs, I more the rest a little up or down and then I shoot it again. Eventually, I start getting a straight line of arrows across the paper. 

I have never done this at extended yardages. I am guessing, that if they are striking the same at 20 yards, they have stabilized and I would not see any difference at extended yardage.


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## Deezlin (Feb 5, 2004)

capt ace said:


> Whats wrong with sighting in your 20 pin before you walk back as long as you don't touch it while your walking back? In other words why can't you sight your twenty yard pin in first at twenty yards to hit the aiming mark and then do your walk back tuning?


I wouldn't see any reason you couldn't, you would haved save about 40 yards of walking!!!


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## Deezlin (Feb 5, 2004)

*Is bare shaft tuning worth it?*



JAVI said:


> When bareshaft tuning.... make sure the target is at shoulder level....


Yes, that is a good point.

I am really not sure, if bare shaft tuning does much. I don't think Easton recommends it for release shooters and I have never bothered too much. I like to shoot the horizontal line it helps out.

The reason I don't is because I see the arrow oscillation as vertical for a release shooter. It the arrow has stabilized fully at 20 yards, then I guess it has merit. But, if the arrow had a high FOC or low FOC, I see the results changing. If the spine is either too stiff or weak, I can also see problems.


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## Deezlin (Feb 5, 2004)

*Is bare shaft tuning worth it?*



JAVI said:


> When bareshaft tuning.... make sure the target is at shoulder level....


Yes, that is a good point.

I am really not sure, if bare shaft tuning does much. I don't think Easton recommends it for release shooters and I have never bothered too much. I like to shoot the horizontal line it helps out.

The reason I don't is because, I see the arrow oscillation as vertical for a release shooter. It the arrow has stabilized fully at 20 yards, then I guess it has merit. But, if the arrow had a high FOC or low FOC, I see the results changing. If the spine is either too stiff or weak, I can also see problems.

I don't see much need to worry about the arrow flight before it is fletched. I would rather see where it is sticking after.

Now, I usually set my nock so it is a little higher that the rest which usually starts at around the center of the berger button. Is there any harm in move the rest verses the nockset. It is uaually a lot easier for me.


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## lefteye (Oct 24, 2005)

*tuning*

Thank you nuts&bolts. This site is terrific - Old Dogs learning new tricks from Expert Old Dogs.


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## karday (Aug 20, 2002)

[. Is there any harm in move the rest verses the nockset. It is uaually a lot easier for me.[/QUOTE]

The relative delta between the two is the same regardless if you raise/lower the nock or raise lower the rest. i use the rest because it is easier. i set the initial nock point withthe bow square and then make the rest if any by moving the elevatio of the rest. If the nock needs lowering then raise the rest and vice-versay.


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## nuts&bolts (Mar 25, 2005)

*Adjust tied nock points or raise/lower rest*



karday said:


> [. Is there any harm in move the rest verses the nockset. It is uaually a lot easier for me.


The relative delta between the two is the same regardless if you raise/lower the nock or raise lower the rest. i use the rest because it is easier. i set the initial nock point withthe bow square and then make the rest if any by moving the elevatio of the rest. If the nock needs lowering then raise the rest and vice-versay.[/QUOTE]

karday:

Moving the rest up or down works. 

Using tied nocks and twisting the nock point up or down works.

A third way is to purposely adjust one of your limb bolts say 1/4 turn. This also works.


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## deerdad (Feb 6, 2003)

When you are done with the walkback and go to the paper tune (spine),
and you find you tear one way or the other, do you have to go through the walkback again after moving up or down one size in spine to correct for left or right or would you leave the center shot alone since it was set regardless of arrow spine?

Greg


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## nuts&bolts (Mar 25, 2005)

*Adjust draw weight to match the arrow or use OnTarget2! software*



deerdad said:


> When you are done with the walkback and go to the paper tune (spine),
> and you find you tear one way or the other, do you have to go through the walkback again after moving up or down one size in spine to correct for left or right or would you leave the center shot alone since it was set regardless of arrow spine?
> 
> Greg


Greg:

If you can hit the weighted string at all distances, you probably don't have a spine problem. If when you try paper tuning after you finished walkback tuning, and you have a tear, try adjusting the draw weight up or down, to see if this will correct the tear.

You can make your own custom weighted tips (add weight) to weaken arrow spine. Just take lead shot and insert into the target point and then seal it with a dab of hot melt glue. It helps to have a digital grain scale so you can measure how much the new target point weighs.

If you need to stiffen the arrow spine, you can add a full arrow wrap on the back end of the arrow, and then refletch with larger plastic vanes. If this does not stiffen the arrow enough, then find a fellow archer who has an arrow saw and try shortening the arrow shaft by 1/4-inch.

Any time you change your arrows, it doesn't hurt to check. All you need to do is hang the weighted string and see if you can hit the string at all distances.


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## One Good Shot (Nov 15, 2005)

*How About Finger Shooters?*

Very well written nuts&bolts. I copied and saved it too.
Just one question. Since I'm a finger shooter, would the rest adjustments be the same as with a release,
or reversed as they are when paper tuning?
Thanks.


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## nuts&bolts (Mar 25, 2005)

*Yup, walkback tuning is the same for a finger shooter*



One Good Shot said:


> Very well written nuts&bolts. I copied and saved it too.
> Just one question. Since I'm a finger shooter, would the rest adjustments be the same as with a release,
> or reversed as they are when paper tuning?
> Thanks.


One Good Shot:

Yup, walkback tuning works for finger shooters as well.

I will let you in on my secret for walkback tuning for finger shooters. I test at 10, 20 and 30 yds.

I use a shibuya plunger button and I set my approximate center shot (right edge of arrow shaft lined up with the left edge of the bowstring) using washers between the head of the plunger and the riser.

Now, take a coke can (or pepsi), and cut rectangular shims 1-1/2 inch high by 1-inch wide of aluminum. Measure the outside diameter of the plunger barrel, and draw two lines down the center of the shim separated by the o.d. of the barrel.

Using sharp scissors, cut along these lines up to the middle point of the shim. You are cutting the legs of a horseshoe shim or an upside block letter "U" shape. You now have three legs on the shim.

Bend the center leg up and out of the way. See if the opening in the center is a good fit around the barrel of your plunger. Keep trimming until the horseshoe shim fits easily around the barrel of your plunger. You want the legs of the shim long enough to reac down to the bottom of your washers.

Crease the center leg of the shim and keep bending back and forth until the center leg snaps off. You can trim the 4 corners of the shim so you dont cut yourself later.

Now, make 10 or 20 of these shims.

For a finger shooter, if you are using the plastic Hoyt Super Rest and a plunger, you adjust center shot by adjusting the position of the plunger.

When I am fine tuning plunger position, I take out or add washers as needed, and when I am super fine tuning centershot, I start adding or taking out aluminum soda can shims.

Yup, one shim makes a noticeable difference in how well one is hitting the weighted string at 30 yards.

Ok, so the secret to walkback tuning for fingers shooters is just between you and me, ok? :zip: :wink: 

nut&bolts.


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## One Good Shot (Nov 15, 2005)

nut&bolts

OK, mum's the word. :zip: 
Maybe I'm doing it the hard way but I'm not using a plunger style rest. Don't tell anyone,:secret: because I hear it's unusual to be able to get away with it.
Until recently I used a prong style but just installed a Nap 2000 that I modified to work off the down cable.(Incredibly faster drop)
I do like the idea of using shims for micro adjustments. Seems so much easier than trying to measure or guess.
I could try that by putting them between the riser and the rest mount couldn't I? Maybe about 10 of them as a starting point to add or subtract from. 
How's that sound? Other than that, */* means move the rest to the right and *\* is left with either fingers or a release?
Thanks for all the info.

.....Dan


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## nuts&bolts (Mar 25, 2005)

*Shims are the way to go*



One Good Shot said:


> nut&bolts
> 
> OK, mum's the word. :zip:
> Maybe I'm doing it the hard way but I'm not using a plunger style rest. Don't tell anyone,:secret: because I hear it's unusual to be able to get away with it.
> ...


Dan:

Yup, shims are the way to go to make micro adjustments. Add a shim, change your mind, take out two shims, etc.

If you are a fingers shooter, and not using a plunger, then you have an incredibly clean release technique, and you have the perfect match between draw weight, arrow spine and tip weight.

I am very impressed. Keep up the great shooting.

Alan


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## One Good Shot (Nov 15, 2005)

Hey Thanks,
It's not perfect, but I'm working on it. I'm using the finger version of the surprise release. I do totally blow some shots but at least I'm aware of what went wrong. Maybe there's hope for me. LOL. Right now I'm just managing to maintain without too much improvement because of Canadian winter and nowhere to practice inside, but I get out and shoot when it's not too ugly outside. I sure spend a lot of time studying though. I feel like an internet archery bookworm.
.....Dan


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## steve-o (Nov 29, 2005)

*center shot*

Have your bow set up by using a laser center shot tool.
This tool is place on the riser where the sight goes (after the sight is removed), then adjusted to be shining centered on the string, then rotated to see the arrow alignment. You want the laser beam to be shining on the center of the arrow from nock to point. Now your center shot is correct. This is the quick description, theres more to it, but you get the idea.
Steve


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## One Good Shot (Nov 15, 2005)

steve-o:

Yep, I follow you. It is a good starting point.

I've done it the el cheapo way by clamping a level as a straight edge to the outside of the riser and measuring to the string and to the center of the arrow tip with calipers. 

It checked out perfect at a shop on their center finding tool. It wasn't laser though. But what the heck? I shoot with fingers so I have to adjust the rest to the left from that point anyway.


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