# Mathews and centershot???



## Daniel Boone (May 31, 2002)

*I would move it out of center shot*

I would move it back a little then do some group tuning.


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## thumperX (Jun 9, 2004)

*centershot!!*

Mathews centershot is sappose to be 13/16!! but thats a starting point!! 1/8 of an inch is not that much!! move it back and check it with a "L" wire from nock to arrow front and then shoot it and use the walk back method to check how centershot is then!!!


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## Midlife Crisis (Mar 24, 2004)

Setting ATA (per Vince on Mathews Inc chat):

There has been much discussion about ATA and setting it properly. I have had many Switchbacks that needed tuning and one thing I have noticed is that rarely is there any consistency in how the idlers are aligned. This is due to the harness knots settling during the shipping procedure. Every single bow that I've tuned has allowed me to obtain a bare shaft bullet hole with the centershot set at 13/16" with the following method: Keep in mind that this is for a RH bow and the opposite sides would be used for a LH bow. The right and left are used as you're looking at the bow like you're holding it to shoot.

I max out the limbs to take my spec measurements. I back out the limb bolts 6-7 turns (7 usually but 6 if I feel too much thread resistance) and then press the bow. I take the cable loop and twist until the ATA measurement on the right side measures exactly 33" from the centerlines of the axles (31.5" for Outbacks). Once this is set with the limbs maxed out I look at the cam to see where it's orientated. I adjust accordingly until the timing holes run parallel to the bowstring putting equal twists in both loops of the string to maintain the balance of the factory twist. After this is done I set my nocking point directly inline with the center of the berger button so my arrow sits perpendicular to the string. I then set my centershot to 13/16" at the berger button.

Once this is accomplished I use a carbon arrow shaft (no bending) with a field tip to set my idler. I take the shaft and run it along flush on the left side of the idler wheel at a length that permits the field tip to end at the nocking point. I then twist the left side cable harness so that the field tip point touches the string at the nocking point. At rest the idler is canted outward from the riser on the top and inward at the bottom (the idler is canted at the top to the left and at the bottom to the right), but at full draw it's straight up and down.

Every Switchback and Outback I've done this to, along with setting the rest at 13/16" centershot has enabled me to shoot a bare shaft bullet hole through paper and arrow flight at longer distances has been superb. I use this same method for the forum members who have sent their bows to me with the same stellar results.
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A2 (Bob Jenkins): here at the factory we set the ATA on the arrow side of the bow only and adjust the yoke system to make sure that the string tracks off the idler wheel straight at full draw……. how the bow fits in YOUR hand will determine the amount of twist that go into the yoke system and your axle to axle may or may not be the same on both sides ...........
You may have to twist the cable quite a bit to get the brace height measurement right. Then the string will take even more twists to get the cam timing right. A general guideline is for every twist you put in the cable (cam end) put two in each end of the string.

Do not add more than four twists to the cable at a time and do not twist the cable to the point that you exceed the factory spec., or bad things could happen. After each twist series, take the bow off the press max the limbs out and check the brace height and cam timing. If they are not correct back the limb bolts out 7 turns and put the bow back in the press and repeat until you get the bow in spec. Once the brace height and cam timing are right the axle to axle will fall in place. Do not be too concerned if the axle to axle is off by as much as 1/8 of an inch.
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Lining up holes on cam: if the inner hole tips towards riser twist up cable and if inner holes tips towards bow string put EQUAL twist into the string on each side of the cam... Twist the cable at the cam end, and the string equally at each end.
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6. The idler wheel lean is key! Take an arrow (preferably carbon) and lay it flush along the left side of the idler wheel with the bow at rest. The tip of the field point on the arrow should be at the center of the string when it is near the nocking point on the string. This means at rest the wheel is leaning with the top of the wheel leaning slightly away from the riser. If the arrow tip is to the left of the string (away from riser) when you measure it, add twists to the left side of the yoke until you get this alignment. This allows the string to feed into the wheel properly. If your cam lean is set properly, the ATA on the right and left side will not be the same, that's why you should just measure it on the right side and only adjust the left side of the yoke.
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1.	Now measure the distance from your thin string to the bow string all the way down the bow. If it’s not the same distance all the way down the string you will need to put twists in the cable to the cam, or remove twists, whichever is needed.
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All that said, I did not follow these instructions. I copied them from the site as Vince seems to be highly respected there.

My centershot is 11/16". I shoot bullet holes on fletched arrows at 1 yard, 2 yds, 3 yds, 5 yds, 10 yds. I tuned (using the Easton guide) to get my broadheads to group with my field points (had to back out the limb bolts 1 turn to get the broadheads to move left). My bare shafts do not shoot bullet holes, and hit the target at an angle from 20 yards. Guess I'll just have to use fletched arrows when I hunt.

At the end of the season I might try to tune the bow with Vince's method.

Good luck.


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## Jose Boudreaux (Oct 18, 2003)

I don't think I have ever had a bow do well for me on centershot  

Hit a baby x or 10 ring(depends what side of the bed I woke up on :zip: ) on a 3 spot fita face at 5 yards

do it again at 40 yards...that's my centershot...


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## stickflinger76 (Mar 18, 2005)

*ThumperX...*

Thumper what is a "L-wire" I am unfamiliar with this?? And to all thanksfor the help, I am starting to see the picture. Happy shootin' to all!


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## vince71969 (Apr 17, 2004)

The "L" wire method will give you centershot when the bow is static (at rest) not at full draw with torque on the limb and the cam loaded. At 13/16" the arrow will be off to the left but at full draw everything will be inline. :thumbs_up


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## Blazer (Jul 5, 2004)

stickflinger76 said:


> I . Still cannot get it to shoot were i aim....they were convinced it was my grip and advised me to change my grip. After many many attempts to change my grip,it still isn't helping. Wouldn't it be easier to just move the rest and find a "good" center shot and be able to hit what you aim for vs. perfect center shot and no way to aim? Any advise would be appreciated.



STICKFLINGER, I shoot a Mathews LX. As you have told center shot for a Mathews is 13/16". I just put a new NAP drop-away rest on my LX two days ago. After getting it set up properly, I done some shooting. And as usual after about a dozen shots or so I would get some erratic arrow flight (visible with my eyes) and not very consistent shooting. Every time I go out to shoot my first shots are the best (thank goodness). My point is this, I will notice it is my grip. I will have my wrist twisted towards the bow and this in turn causes my arrow to go left but eventually the feathers take hold and stabilizes it out, but still not a true shot. Just yesterday I wanted to watch college football and shoot my bow. I have the capability to shoot from inside the house. I can open my sliding glass door in my den and shoot out into the yard at my Morrell target. I'm shooting Magnus broadheads. I used my laser range finder and it put out 42 yds. as the distance. My first shots were great.
I like to shoot at the black side of the target because it gives me a good background and the yellow feathers show up well going down range and I can see what the arrow is doing and plus my bro would stand behind me and tell me what he sees. I get lazy on my grip and this causes my earratic arrow flight. I'm not saying this is your problem, but do keep it in mind. I know it's mine at times, because 95% of my shots is a thing of beauty seeing that arrow going dead on and a good spin on them and that tells me when it doesn't, it was me torquing the bow..... :wink:


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## ManHunter (Sep 10, 2005)

*Ignore the "Pro" Shop*

ThumperX had it right; 13/16" is a starting point. The practical "center" of the bow is not just dependent upon physical measurements, it's also dependent upon your shooting style, your equipment, and minor variations in the manufacturing of individual bows.

The most important point, however, is that no one else can truly "tune" your bow for you. It may take awhile to learn, but find a tuning technique that you can understand and do it yourself. Some methods are very... methodical, while others are very intuitive and easy to understand. A pro shop can only get someone else's bow close; it's up to the individual to tune it himself.


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## stickflinger76 (Mar 18, 2005)

I do agree, after a few more afternoons shootin' n tunin' my bow I have found the sweet spot for me, just a little to the right from "centershot" aprox. 3/32 and man is this thing groupin'. Did the walk back center shot and am very pleased. Once again thanks to you all for the help!


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## jbcoop73 (Sep 14, 2005)

I cant tell you how many times i performed the walk back method and every other possible way to achieve perfect centershot with my switchback. i did start with 13/16 but the magic is at 11/16 for me. as already stated only you yourself can find the sweet spot for your own set up over time. if the pro shop guys could do everything for us we wouldnt have a site like this to debate about it. Trial and error is the only way.


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## Keith1299 (Dec 14, 2003)

Can anyone tell me if the idler alignment is the same for all single cam bows or is this a mathews thing? I have a parker 31ul and after replacing the string and cable i wasnt sure on how to set the idler lean. Keith


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