bow tuning question

[JJ Overkill]

ill try and make this short,

heres my setup, just for reference. bowtech 350 detroyer, 30" dl, 70#. arrows are 29" 300 spined gold tip xt hunter arrow 125gr head 4 fletched w/ vane tech 2"

i paper tuned my bow yesterday, used a 350 spined arrow w/ 100gr field point. then played with a 300 spined arrow to see what weight i could put on it. found it only handles a 125gr head, a 150 shows a slight nock left tear, i could probley tune it out but im scared of a possible weak spine issue. ( arrows belong in animals, not my bow hand).

ok here is what happened today, sighted in at 25yds (good), 40yds (good) 50yds the arrows statred to hit right 2", at 60 arrows went right 4" approx. i started to question my tuning, and arrow spine. i put a 100gr head on the 300 spine still hit right. the only thing i could think is i needed to move my rest left just a touch. did that and move the rest to far at 50yds the arrows were 3" left of target. moved the rest right just a little bit and everything came together.

heres the question i guess, have any of you had to move your rest while shooting field points after tuning? ive had to do this with broadheads to get them to group with field points but never while sighting in.

any info or experiance on this would be great. thank you

[ctdad]

That is a modified version of walk back tuning. Now i would broadhead tune

[cnelk]

What kind of rest are you using? Just curious.

[>>>---WW---->]

http://www.youtube.com/watch?v=Dm_mBH9lhRw

Here is one way to do it. I really like Kenny Parsons tips.

[WindedBowhunter]

In case the "What is Walk Back Tuning" question comes up:

Most of the stuff should be valid for all types of bows (longbow, target recurve, compound), all types of arrows with target or field points or
broadheads and for finger as well as for mechanical release shooters.

It is assumed that one starts with an arrow which is not totally wrong for the bow (look into the arrow selection charts of the manufacturers!)

Everything else like the string length for example should be set to a reasonable value (maybe you use the recommended values from the
manufacturer...). If you don't have a cushion plunger just ignore the remarks about the plunger. If you have an adjustable rest you can apply
the remarks for the plunger.


While the paper tuning test might help you to tune your compound shot with a mechanical release it might be somewhat misleading when used
only for a single distance as all other single distance "tuning" methods.

All those methods have a major drawback: they will help you to setup your bow that it is tuned for this distance, but for any other distance
it might be completely de-tuned. The method described here overcomes this drawback by shooting at different distances and works for all types of
bows and shooting styles.


The distances given in the following method are just a suggestion.

Preparation:

Get a ruler, a pen, a fletched arrow and an unfletched arrow (same spine, point, length, etc.) which are _PERFECTLY STRAIGHT_


Make a target face which looks like this (take the back of the biggest target face available and make this drawing as big as possible):


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------------#-----------

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You should always aim at the # in the middle of this cross.


Now make several blank diagrams like this:

30m -------+----+----+------

| | |

27m -------+----+----+------

| | |

24m -------+----+----+------

| | |

21m -------+----+----+------

| | |

18m -------+----+----+------

| | |

15m -------+----+----+------

| | |

12m -------+----+----+------

| | |

9m -------+----+----+------

| | |

6m -------+----+----+------

| | |

3m -------+----+----+------

-7 0 7



The x axis gives the distance in cm of the arrow from the horizontal or vertical (this depends from what you are tuning) centerline.


Set the sight to approximately 30m (if you are a barebow archer, just remember to aim always in the same way as if the target were 30m away -
regardless how far it is away).



Everything which I describe is valid for a right hand archer (the arrow is on the left side of the bow if one looks from behind) - for a left hand
archer it is the opposite...



Step 1 (coarse adjustment):

Set your cushion plunger (or Berger button) head so that the arrow is exactly in the center, the pressure of the spring should also be set to an
intermediate value. Set the aim so that it is also at the center (horizontal).

Set the aim vertically to 30m.

Shoot a few fletched arrows at the target and look where the group goes.

If it is left from the center increase the spring tension, if right decrease the tension. Repeat this procedure until the group is at the center.

The spring tension should be in the intermediate region. If it is much too weak the arrow is way to stiff, if it is much too strong the arrow might be
not stiff enough, in this case you could try moving the position of the cushion plunger head a little bit left and decrease the tension, then repeat

step 1 until the group is in the center.

Step 2 (arrow selection):

Shoot a fletched and an unfletched arrow at all the distances marked on the chart. You should always aim at the same point. Measure
the HORIZONTAL distance from the VERTICAL center line and mark these values in your chart. Now connect the points for the fletched arrow
and connect the points for the unfletched arrow.

The line for the fletched arrow should always be near the 0 line (if not, look at step 4). Now look at the line for the unfletched
arrow. If the arrow is ok, it should be more or less parallel to the line for the fletched arrow and you are done with the tuning.


Here are a few deviation patterns:

O denotes the unfletched arrow

X denotes the fletched arrow

* denotes both on the same spot

30m -------+----X----+------

| | |

27m -------+---X+----+------

| | |

24m -------+---X+----+------

| | |

21m -------+----+-X--+------

| | |

18m -------+----+X---+------O

| | |

15m -------+----+-X-O+------

| | |

12m -------+---XO----+------

| | |

9m -------+--OX+----+------

| | |

6m -------+-OX-+----+------

| | |

3m -------+--*-+----+------

-7 0 7

It starts to deviate at distances less than 15m:

This means the arrow is not stiff enough - get the next stiffer one.

If it deviates to the left, it is too stiff - get the next less stiff one.

30m -------+----X----+------

| | |

27m -------+---X+----+-----O

| | |

24m -------+--X-+---O+------

| | |

21m -------+----*----+------

| | |

18m -------+-O--+-X--+------

| | |

15m -------O----X----+------

| | |

12m ------O+-X--+----+------

| | |

9m -------O--X-+----+------

| | |

6m -------+-OX-+----+------

| | |

3m -------+--OX+----+------

-7 0 7

It starts to deviate at distances greater than 15m:

The arrow is not stiff enough - cut it a little and/or get a lighter point.

If it deviates to the left, it is too stiff - get a heavier point and/or choose a longer one.

If both lines intersect: your setup of the cushion plunger is wrong...


30m -------+---X+O---+------

| | |

27m -------+----*----+------

| | |

24m -------+---OX----+-----

| | |

21m -------+--OX+----+------

| | |

18m -------+---XO----+------

| | |

15m -------+----XO---+------

| | |

12m -------+----OX---+------

| | |

9m -------+---X+O---+------

| | |

6m -------+----XO---+------

| | |

3m -------+----+*---+------

-7 0 7

The setup is OK.


30m -------+----+X--O+------

| | |

27m -------+--X-+--O-+------

| | |

24m -------+OX--+----+------

| | |

21m -------+----+-X-O+------

| | |

18m -------+--X-+O---+------

| | |

15m -------+--O-X----+------

| | |

12m -------+----+-XO-+------

| | |

9m -------+--OX+----+------

| | |

6m -------+---O+X---+------

| | |

3m -------+---X+O---+------

-7 0 7

Although within the tolerances, you might want to change something in your setup: use a heavier arrow, adjust the cushion plunger, change the
string length, change the stabilization...


Step 3 (nocking point):

Shoot a fletched and an unfletched arrow at all the distances marked on the chart - just like in step 2. But now measure the vertical distance
from the HORIZONTAL center line and mark these values in your chart.



How to interpret the curves:


30m -------+----+---*+------

| | |

27m -------+----*----+------

| | |

24m -------+-*--+----+------

| | |

21m -------*----+----+------

| | |

18m ------*+----+----+------

| | |

15m -------*----+----+------

| | |

12m -------+*---+----+------

| | |

9m -------+--*-+----+------

| | |

6m -------+----*----+------

| | |

3m -------+----+-*--+------

-7 0 7

Both curves are parallel - the nocking point is OK.


30m -------+----+--X-+------

| | |

27m -------+----X----+------

| | |

24m -------+-X--+----+------ | | |

21m ------X+----+----+--O---

| | |

18m -----X-+----+--O-+------

| | |

15m ------X+----+O---+------

| | |

12m -------X----O----+------

| | |

9m -------+-X--+O---+------

| | |

6m -------+---X+-O--+------

| | |

3m -------+----+X-O-+------

-7 0 7

The nocking point is too high.


30m -------+----+---X+------

| | |

27m -------+----X----+------

| | |

24m -------+-X--+----+------

| | |

21m -------X----+----+------

| | |

18m O ------X+----+----+------

| | |

15m --O---X+----+----+------

| | |

12m -----O-X----+----+------

| | |

9m -------+OX--+----+------

| | |

6m -------+--OX+----+------

| | |

3m -------+----OX---+------

-7 0 7

The nocking point is too low.

Here is a video that provides some additional insight to WalkBack Tuning

I hope that this helps some...

[buglmin]

Lol...gotta question for you. On your bowsite, bow you have a level? At 50 and 60 yards, are you holding your bow level?
The reason youre seeing problems at 50 and 60 yards is cause distnce shows problems you dont see at 20 yards,but start to notice a lil at 40 yards. Plain and simple, the arrows aint tuned. Put a lighted nock on, and you'll notice things. Cut the vanes off an arrow and shoot it at 10 yards. Bare shafts should impact the target straight on. I always acrry a bare shaft in my 3D quiver to make sure the arrow is flying perfect at 20 yards...
Other things to check is cam lean, especially on big cam bows like your bow.

[Whitetail180]

Put a couple of twist in your Left yolk, this will usually take care of the left tear.

[JJ Overkill]

[quote="Whitetail180"]Put a couple of twist in your Left yolk, this will usually take care of the left tear.[/quot ]

thats not really such a good idea. ive had this bow tuned a few times. most bows these days have cam lean induced in them from the factory. ( found that out the hard way). if i was getting tear left on an arrow that i knew for sure was the right spined arrow i would move my rest before i touched my strings. a nock tear left is a possible big hazard. in a tuned bow it indicates a weak spine. over time weaking the arrow. there are plenty of pic on-line with broken arrows sticking in peoples hands.

on this bow i made sure the timing marks are the same. ata is good. string stops are touching at the same time. made sure my rest is coming up within the last 1" or two of my draw cycle to make sure its not pulling on my bottom cable. (prior mistake). everything is checking up good.

im currently working on the tuning thing that windedbow hunter put on here. im only doing one thing at a time to try and take fatigue out of the question.

and my rest is a QAD hd

[Swede]

I have found I am well off tuning the bow so that the broadheads and field points hit at the same spot. I have determined that pater tuning is hardly worth the effort. I can paper tune the setup to perfection one day, then try it again on the next and have a tear. Half of the equation is the shooter. When I get the broadheads and field points shooting together, I have never had a "tuning issue."

[ctdad]

Putting more attention into your form is a great way to fix your issues. Humans have a lot harder time being consistent than bows do. Stick to your current plan and you'll have it shooting better than your capable of in no time

[JJ Overkill]

i completely agree with ctdad and swede,

i paper tune just to get a good rough in. the true test comes when shooting broadheads. the reason for the post was the arrow going left at 60yds when it was hitting dead on at 40yds. i basicly did what i would have done with a broadhead and make a minor adjustment to the rest. im still up in the air on what head i want to shoot this yr. plus i might have just picked up a anouther bow, making this one my back up. the new bow will be a real treat with a max draw of 95#.

form is a key to all this, when i sight in its a max of 25 shots just to make sure my form and arms are good.

[buglmin]

It takes me days of tinkering and playing before I finally decide my bow is tuned. Trying different arrows, different heads to see which ones group the best. Right now, Im in the process of setting up a Darton 3900, and in just two days, Im still playing with arrow spine. Not too concerned bout broadheads yet, cause with the perfectly spined arrow, broadhead flight will to easy to tune.
Why are you moving the arrow rest? Moving the arrow rest to get arrow impact at 60 yards will change impact at 20 yards, at 15 yards. I just came in from doing this, and noticed the differnce in arrow impact. I assume youve shot several different broadhead makes and weights before adjusting your rest...? Have you tried different arrows? Too many variables to try before you should be satisfied...

[JJ Overkill]

buglmin, your right on the tinkering. i found it didnt matter what arrow weight / head combo i used at 60yds i was hitting right. wait what did i write before.?. i moved the rest left, was hitting right. sorry for the confusion on that. anyways. everything hit the same spot a 60. i made a small adjustment to my rest moving it left, and by small i mean 1/16" maybe even less. after making the adjustment i went back to 25yds. (my top pin) ran through all the yardages again and hit just fine.

i was just wondering if anybody has ever seen this in all there tuning? it would be a long version of walk back tuning, as mentioned before.

[WindedBowhunter]

jerinmn - to answer you last question, if you have performed the walk back tuning, adjusting your rest and/or arrow shafts to tune well as swede stated, then these are issues that I have personally still seen:

Are you warming up by exercising or stretching prior to shooting 60+yds? Or are you shooting multiple arrows at 20, 30 and on?

Shooter "issue" - vague, no?! I have see shooters pull there shots on a specific target at a certain range. Simple change, I did was physically change the target. I swapped out the bag for a block shape or 3D. Sounds weird, but the mind can play tricks

Just put the bow down and come back in a few days... It may not be the bow (most common in my experience)

Outside conditions - is there more than a 5mph crosswind? This can wreak havoc on initial tuning. I have seen this before on just a few occasions. The shooter was dead set on shooting past 50 yds, so we had to up his arrow weight and retune the setup... they were good. Just a bit of wind at the end of the arrow flight's momentum is very susceptible to wind drift.

Just my 2 cents...