Jerry/Pa

Another question in my obsession for perfection. Does spine effect center shot? If I shoot two different spined arrows from the same bow will I need to adjust my center shot for both arrows. #2) What is the tolerence of center shot? Is it an exact postion or can it be as much as an 1/8 inch right or left? Once a bow is set for a shooter does center shot ever change? JERRY

Len in Maryland

Jerry:

Looks like you' re not getting too many takers on your questions.

Let me just tell you this. Centershot is as about as misunderstood as many of the other ' tuning' concepts derived by those trying to achieve a basic description. Many will get frustrated by not having ' absolute' answers and seek other means of archery which is not so demanding.

Even if you use the most sophisticated center shot tools, you still have other variables with which to contend and which will alter that setting. Given that centershot tools work on a static bow situation, it many times will give you a wrong setting for dynamic (bow at full draw) situations. The centershot tool also demands that the surface where it' s being mounted is absolute with it' s relativity to the other components and surfaces of the bow.

Some of the things that will negate ' factory type' suggestions, centershot tool suggestions, or ' internet forum' suggestions for centershot are; the amount of tolerancing you have in YOUR bow, the type of rest that you have on YOUR bow, and how much YOU torque YOUR bow with either YOUR bow hand or YOUR release hand.

One other thing that we have found that will affect centershot quite a bit on certain types of rests is how much the cable guard flexes at full draw. This will become, of course, more prevalent with higher brace height bows where longer cable guards are required. In effect, this is one more advantage of the Hoyt ' Tec' riser designs.

Now, I' ve probably opened up a ton of questions. Hope this at least sheds some light on the subject; but, please don' t expect me to expound on these tidbits of information. It would take a small novel.

Jerry/Pa

It' s the weekend Len. I firgured I' d see more when all the techues get back to there shop or computers. Thanks for taking the time. You bet I got questions.lol I wish there was a book or video that had all the info about bows set-ups and tuning. I have some but I' m looking for the advanced advanced course. I think I know most of the answers to this post. I just wanted to confirm them or ajust my thinking if I' m wrong. I know torque is a big factor but I' m not too sure about spine. I usually eye ball center shot initially then shoot it in at the range. Mechanically it works for me I just want to understand the theory. JERRY

Fletchead

Yes spine affects center shot. Len are you talking about the rod flexing at draw, or being under to much stress to begin with.Ive seen problems when people set them up for to much arrow pass,and have side stress, but never even really thought about the flex difference at draw.Len your cable guard answer brings up another question from me. Are there certain brands of bows that are more likely to have this problem, and what has the least amount of twist. Offset, or straight, and Carbon rods or steel.

Len in Maryland

Fletchead:

It varies with riser design and the type of material that is used. You saw me mention the ' Tec' riser being better at controlling this problem. The reason is quite obvious in that the rod length is supported in two places and the distance from the ' Tec' end to the end of the cable guard is subsequently much shorter.

The material composition is a key factor. For instance, if an aluminum rod is used, what grade of aluminum did the manufacturer select? I did have a major problem with a customers bow and proceeded to remove the carbon rod and replace it with a steel rod. The problem was eliminated.

TFOX

Len,was that a major problem on the old Hoyt Raptors.I had someone bring one to me to tune and this thing just wouldn' t act right.It acted like the cable guard was loose.It was loose but I fixed it and it got better but was still doing the same thing.Couldn' t get the thing to paper at all.It kept showing a stiff arrow,regardless of the adjustments I made.I also suspected bent limb pockets but had no way to check.


I did a lot of twisting and turning on this bow and got it shootable but I never was satisfied.

ijimmy

This is great , good info to apply to our never ending quest for " perfect arrow flight " . I' d like to add some questions here . If you keep the center shot the same and use a stiffer spine will the arrows walk to the left with a right hand , compound , release shooter . With the resent threads on broadhead tuneing in my mind arrow spine seems to be about the most critical aspect that is easyly changed to correct poor flight " with broadheads " . Since easton says bare shaft tuneing is for finger shooters does that mean it does not aply to release shooters ? I' ve heard others say they use it with releases . And lastly [ not to open up anoter can of worms ] but if trying to get broadheads and field points to hit the same is' nt viable , why does easton list it as a tuneing method ?

Len in Maryland

TFOX:

Yes, the Raptor (among some of the others) could be a ' bear' to tune. It had a steel rod and could shift if the guard was not locked down tightly with all the set screws provided. The design of how the rod was mounted was so good that they kept it for a while, didn' t they?

Back then we pay too much attention to the cable guards. Now we do! Like you, we just tried like heck to tune around it.

ijimmy:

You' ve got too many questions. I think you' ll have to take my course.

ijimmy

Len if you were' nt have way across the country I' d probably be pounding on your door . By the way I' ve got my mavric recurve shoot' n good useing a trophy taker , it likes that rest and is alittle quieter with it than the zerro effect I had on it . I' ve got to get it shoot' n dead nut' s before season as the guy' s in Pa where I hunt say its the only bow I can kill a deer with up there , they love their darton' s .

TFOX

Hey Len,the best way I found to tune this thing was to just grab the grip.It seemed the induced torque was what this bow wanted.I didn' t even try to teach this person how to properly hold a bow because his bow reacted horribly to a loose grip.Didn' t like it but it worked.