I am looking for some really knowledgeable tuners who don't mind lots of detail and who can help a guy out who would like to be more knowledgeable himself. In my deer camp in Northern Ontario, there are so many guys that honestly have never really heard of tuning and I do my best to help them. But, quite frankly I am in need of help!!
Page 7 of the 2009 Easton Guide that I have, shows a paper tear with tail right. It attributes this to a spine that is too stiff or arrow rest too far to the RIGHT. It suggests moving the arrow rest to the LEFT which I believe is wrong. The arrow rest, I believe is too far to the left to begin with and needs to be moved to the right (towards the bow). I visualize this and figure that the rest is too far to the left, which causes the arrow to leave the bow yawing to the left. This in turn causes the tail end of the arrow to be to the right(horizontally) of the tip as the arrow travels. Hence the tear of the vanes are to the right of the tip as the arrow passes through the paper.
Conversely on page 7 it shows a paper tear with tail left. It attributes this to a spine that is too weak. It suggests moving the arrow rest to the RIGHT which I also believe is wrong, for the reasons listed above.
I believe both of the above adjustments are wrong both from experience, common sense AND more importantly from the Guide itself which I believe contradicts itself.
On page 11 of the guide it depicts stiff spine (BH's hitting to the left)and directs moving the arrow rest towards the bow (i.e. to the right). I agree with this!
Conversely, it depicts weak spine (BH's hitting to the right)and directs moving the arrow rest away from the bow (i.e. to the left). Again I agree.
Why do page 7 and 11 give completely opposite directions for arrow rest adjustment to correct for spine? YES I know that page 7 is looking at each arrow versus page 11 comparing BH to FP. BUT spine is spine and when I do a visualization of arrows exiting the bow according to horizontal position of arrow rest to movement of the string, page 11 makes complete sense.
Finally, to cap it all off, I am going to post directions from another site that have what I have experienced to be the correct adjustment for right and left tears. It will include a diagram and the prose that go with it, but may have to be in two posts. Note that it completely disagrees with Page 7 of the Easton Guide.
Please, any of you really technical tuning fanatics help me clear this up!!!
best regards from Canada, Canuck.
here is a picture of tears from another Site. And here is the directions for using it. It makes perfect sense to me and seems to be completely opposite to the Easton Guide.
To correct vertical flutter (C), move your nocking point down or your arrow rest up.
To correct vertical flutter (D), move your nocking point up or your arrow rest down.
To correct fletch left (E), move your arrow rest away from bow.
To correct fletch right (F), move your arrow rest toward the sight window.
If you don't seem to be making progress,.. ie the tear seams to be getting worse - make sure you aren't on what I call a "second harmonic". Move your rest back past the point of where you started and try things there. It's possible that you have moved the rest SO FAR from where it needs to be that improvement is impossible.
A fishtailing, or porpoising, arrow will cause a different tear at different distances.
Carbon arrows, especially, can cycle these flight problems so fast that you can't get close enough to the paper to tell which way it's coming off the bow.
Just get it close with paper, at several distances, then move on to more precise tuning methods.
again thanks for your input!
Paper tuning will get you close to the point of getting your arrows leaving the bow in the same way provided you have good form on all you shots. Once you have a good tare you need to move on to getting your target point to hit with your broadheads without loosing good arrow flight leaving the bow.
One cannot tune for someone else as we are all different. The bow is a tool and it must be tuned to the individual shooter. Using a shooting machine in a bow shop will get you started but you need to take it beyond that point.
Generally moving the rest in the direction of the tear works but not always you must experiment to achieve the best results. There are no rules that totally work ever time for every archer.
Stay well !!
I agree completely with you regarding BH tuning (i.e. comparing BH tipped arrow versus the FP tipped arrow impact. If the rest is bit too far away from the riser, the arrows have a left yaw as they depart and the vanes try their best to bring the arrow back. The vanes can't do it to the same amount with the BH as they can with the FP due to the BH not being as easy to "bring back" or straighten out as the FP arrow. Hence the BH impacts to the left of the FP.
However, when it comes to paper tuning, here's where I either disagree or don't understand you and it's the nub of my problem!!!
If the rest is a bit too far away from the riser when paper tuning with a FP tipped arrow, the arrow will have a left yaw in its flight. The vanes are doing their best to straighten the arrow out and the paper tear will tell us how well they have been able to do so. If the paper tear is to the right, it means to me that they were unable to bring the arrow in line. The right tear shows that the tip of the arrow is still to the left and the vanes to the right, as the vanes could not accomplish their mission of getting the tip and the tail of the arrow straightened out, hence the right tear. This in turn says to me that you have to move the rest to the right or towards the tear. This agrees with my second posting but disagrees with the Easton page 7 directions for paper tears.
What do you think Dale?
Common tuning scientists, help out here!!
The only exception to this is walkback or modified walkback tuning. The rest always needs to move in the direction longer range groups need to move.
IMO cam lean accounts for their counter intuitive recommendations. IF you have zero cam lean then doing the opposite should work for left/right tears. Also, whisker biscuit type rests or any rest that stays in fairly rigid contact with the arrow can induce a bounce that also results in doing the opposite to their recommendations even for vertical tears.
Bottom line, do what it takes to get bullet holes at the two distances that Easton recommends.
I did have one old Matthews single cam that shot best with a slight vertical tear...
I think the 2 biggest mistakes guys make is 1.Not knowing they had fletching contact, 2. not making very small adjustments
I have seen guys have trouble with form shooting close to a blank sheet of paper which can make things difficult to diagnose also.
The Easton Guide only makes sense to those who "don't need it". The paper tuning section of the guide has been only about a third correct for years, and is the major reason so many tuners have given up on paper tuning entirely. Spine has VERY LITTLE IF ANY affect on paper tears with a mechanical release fired arow. I can take my sons 35# bow, and fire any shaft from a .650 spine deflection all the way up to a .150 spine deflection, and get a perfect paper tear.... Everyone with proper form and proper centershot& nock location can do the same. Knowing that,... one should NOT consider spine as a tear factor unless shooting fingers(and in some cases single caliper jaw releases).
Paper tears MUST be read correctly before adjustments are made. It's not as simple as moving the rest up, down, left, or right to correct a tear. Those adjustments are only made after I have eliminated as much vertical and horizontal nock travel as possible(see Purdue's cam lean reference above). Cam lean and hand torque are often the largest contributing factors to a bad paper tear.
I have a customer who is a 300 shooter in league and has been for nearly 15 years. He is a former MN MSAA Grand Champion, which is awarded each year to the person with the highest total score in each of the archery venues(indoor, 900, field, & 3D). This guy can out-shoot most guys he faces, but he cannot get a perfect paper tear, and he cannot get same POI with FP's and BH's due to his hand placement and the fact that he uses a kisser in conjunction with his peep and presses it too tightly into his face. I can shoot his bow and get perfect tears every time, so can many others. But he cannot. We spent an entire weekend trying to get him cured of that problem last summer, but too many years of less than perfect habbits are too hard to break for him.
My point of telling his story, is that it's just not about moving stuff around like it tells in the Easton Guide. For some, it works, but for most, it does not.
Yes, the Easton Guide is wrong in many ways(to answer your original question).
The Eastman guide is out-dated with respect to modern compounds and mechanical releases.
The shorter ATAs combined with larger cams have made cam lean and torque two of the most important factors in tuning.
Both are misunderstood by many.
"Here's another way I look at it. As the string pushes the arrow towards the rest that string continues on a straight path. The arrow however is being pushed one direction or the other depending on how far the rest is off center. The front tip of the arrow is being moved out of line in a sort of see-saw or fulcrum effect off the rest. That movement be it ever so slight will cause the tears as the guide depicts."
I agree 100% with your statement above! It's the exact question I have!!! I totally understand why tears occur. It's what the EASTON Guide says to do about the left and right tears that I disagree with.
If the rest is too far out or away from the riser when paper tuning: the arrow will depart the bow with a left yaw (looking at the departing arrow from the shooter's viewpoint)
in other words the arrow is launched ot an angle away )leftwards) to the path of the string
the vanes do their best and try to straighten the arrow out (I see it as a fishtailing action)
the arrow hits the paper with a left yaw if the vanes can't straighten the arrow out in the distance travelled to the paper
if the arrow hits the paper with a left yaw it shows this by a tear right as indicated in the diagram inserted in my second post on this thread (labeled F)
My understanding leads to then agreeing with the diagram diections "To correct fletch right (F), move your arrow rest toward the sight window."
This is exactly opposite to the Easton Guide advice.
Guys that is my one and only question!!!!!
Do the paper tuning experts among us agree with Easton Guide or what I inserted for a left and right tear when paper tuning? AND if so, why am I and the guide that I inserted wrong.
Guys I am not asking if I should paper tune! I DO NOT paper tune!! I use a laser to get center shot and a square for vertical position. Then I BH tune and get perfect groups of FP and BH. My bow is then perfectly tuned believe me!!
I am just trying to understand why EASTON is out of synch with my understanding of arrow flight, my own experiences when I tried paper tuning and the directions I inserted.
I am just a bit of a perfectionist and hate to see misinformation that could contribute to people not getting their bow in tune or giving up on tuning.
OR maybe I don't understand and if so would love to learn something more about arrow flight.
Also, the EASTON guide really screws me up in that I agree completely with their directions for BH tuning. But to me their BH tuning is totally out of whack with their paper tuning directions. To me the EASTON Guide is correct in either its paper directions or its BH tuning directions for left right adjustments.
Where are you technical wizards who love theory!!!??
I suppose if you start with your rest extremely out of whack you will get all kinds of goofy results- don't know about that. But to "do the opposite" has not been my experience. I look past all of that spine discourse- not applicable.
I start at 6-8' from paper with my rest eyeballed at center. I use a dropaway and check for fletch contact first to dispell any chance of false reading. Following Easton guide has been dead on for me. Then I go on to BH tune.
Pretty much what x-man said. It was originally written by and for folks shooting trad bows off the shelf with fingers, where there is little or no horizontal adjustment. Proper spine WAS the adjustment, which not only includes the actual shaft spine rating but also to a great degree length and head weight. In that regard they are spot on.
It is confusing to many not familiar with trad bows and trad bow tuning. IMO that's why there are so many newbie questions about spine WRT paper tuning. "According to the chart my arrows are proper spine but I'm getting such and such a tear when I paper tune....." Modern bows it's 90% (or maybe more) rest adjustment. Get a tool out and start adjusting stuff.
Spine issues from my experience don't usually pop up until broadhead tuning. And even most of those issues usually involve weak spine coming from trying to shoot a lighter arrow for more speed.