Thank you for taking the time to post this

Matt

 

Matt, you're welcome. If you have questions, feel free to ask.

This has always been one of my little "nuggets" that I enjoyed showing my students and friends, while pointing out to them that most of their competitors were shooting bows that were off plane and didn't even know it...

An "ace" up the sleeve as it were. But it's high time that everyone knows this stuff because life is just too short to shoot a poorly tuned bow...

John.

 

Yep. Great stuff and glad that you bought it up again. I have a sneaking suspicion that this setup is covered in "The art of Repetition" by Simon Needham, but it's definitely covered in his "Art of Archery" DVD.

 

Excellent tutorial. Thanks!

 

John, Thanks for setting up Alyssa's bow today. Big thanks for posting this since I was manning my cubicle all day and missed being there. Have I said "WoW" for your 30 "tens" at state that your tuned bow helped you to shoot. Now to check my setup....

 

My pleasure. She's a great young lady and one heck of a shot! We wrapped up the session with her pounding out a nine and two baby "x's" and she left with a big smile on her face. At least now she has confidence that her gear is up to the task and will do whatever she's capable of doing.

John

 

on the Hoyt Formula RX, don't try to remove the dowel without first loosening the little hex screw in the hole where the limb alignment nib seats. The manual makes no mention of it at all.

 

I use something similar to your method, John. My Matrix grip is suited for aligning two arrows as shown. Simply remove grip and use bare riser. Of course if you use all that ergly tape it wouldn't be as easy I've always assumed recurve grips are centered and parallel this way. Is the latest generation this way?

I rubber banded the arrows here to take pics, but normally just hold them for visual check. This way you can check both the orientation of the stab and the string alignment. As you can see here, both are nicely centered between the arrows.

View attachment 1297491 View attachment 1297493 View attachment 1297494

 

what riser face do you use, to square up the bow, when the surfaces are linished, and can be out of plane themselves.
Not all risers are cut square, just like long rod bushes are square?

really good thread, this is just one question ive always had when looking to true up a bow.
i supppose you just have to do your best with what you have eh?

My question is that some risers have the pockets rotationally out. So like an Aircraft you have Yaw Pitch and roll. Yaw is the dovetail left/right movement, Pitch is the limb bolt movement, and roll is something you cant adjust.
Inno CXT Shims are suppose to address this.
BUT if the riser is out of Plane limb face to riser sides, then you will have to adjust with yaw to pull the limb tips inline with the bows centre. which is just simply wrong, the limb just wont track right.
this is my problem with adjustable setups. It accomodates sloppy manufacturing, and only accounts for 2/3rd of the concerns.

if bow pockets are milled at 95 degress to the face, since some swarf got in thier, rather than a clean 90 degrees then this check is simply out of sync.
as the arrows or bow square will sit 5 deg out to square. if you see hwat i mean, but the limbs will track fine as they are in plane with eachother, and in plane to the line of the pocket faces.

 

My question is that some risers have the pockets rotationally out. So like an Aircraft you have Yaw Pitch and roll. Yaw is the dovetail left/right movement, Pitch is the limb bolt movement, and roll is something you cant adjust.
Inno CXT Shims are suppose to address this.

http://www.allstar.fiu.edu/aero/fltmidcont.htm

From the terms, with the bow in your hand facing a target, it seems:

Limb bolt: Pitch
Lateral adjustment (with limb bolt as fulcrum): Roll

Yaw: NA.

I guess you'd have to shim the limb or the pocket.

 

id sooner take a riser where the pockets were 100% true to eachother, and put up with a face being out than limbs tracking badly. the reason for this is the bows launch point is a dot, a single loaction that doesnt care about the squareness of the faces. your button doesnt care, its just your limb alignment that cares since you dont want your limbs tracking oddly as that puts a bit of a fight between them. i suppose its kinda like karma between your limbs. and thats dictated by the risers limb pockets and not the riser sides.

 

thanks for posting this, i'm going to check right away! I've been having weird problems with my bow for a while. These how to topics are much appreciated.

 

It's amazing how after 40 plus years of archery there is still new tricks to learn. Thanks John!

TAO

 

Seattlepop, that's what I used to do with some risers, but I'm to lazy to take off the grip, esp. when I have grip tape wrapped on it. But what you're doing there works perfectly.

Sid, don't get all technical on me now... ha, ha

Yes, some risers make it difficult (like my Bernardini Luxor) to find a matching flat surface on both sides, but I've managed to find one on every riser I've worked on. If for some reason you couldn't, then I suppose you could calculate the centershot of the sight window and measure from there. The sight window is almost always flat on most bows. Measuring centershot is a lot of trouble though, and you have to remember that distance every time and add or subtract it. Much easier to just measure equally from both sides of the bow.

TAO, I think I just saw a couple more light bulbs go off...

Fun stuff.

John

 

John would you mind posting a pic (or just explaining) where you measured your Luxor from - the only spot that looks like it will work is right below the grip.

Matt

 

John, are you saying you can use beiter limb gauges and get your string tracking thru them perfectly, but still not have the bow on plane? Im having a hard time understanding how that is possible? Also what do guys do that shoot non adustable risers, like the Best Moon or others?
Thinking more about this, you are aligning the limbs thru their centers and then laying them both over evenly until the string is tracking thru the center of the riser, not the center of the limbs. You have found this to be more accurate/forgiving then leaving them "in line" and adjusting the plunger in/out? Hard to argue with your success, just hard to get my head around.

 

John, are you saying you can use beiter limb gauges and get your string tracking thru them perfectly, but still not have the bow on plane? Im having a hard time understanding how that is possible? Also what do guys do that shoot non adustable risers, like the Best Moon or others?
Thinking more about this, you are aligning the limbs thru their centers and then laying them both over evenly until the string is tracking thru the center of the riser, not the center of the limbs. You have found this to be more accurate/forgiving then leaving them "in line" and adjusting the plunger in/out? Hard to argue with your success, just hard to get my head around.

This pic shows the Beiter gauges aligned, but the bow is out of plane. In this case, both limbs are canted to the left. I use the gauges and then check to see if that alignment is "on plane" with the riser.

 

this is Hell, getting the limbs to to track true is easy but making them traight with the riser is almost impossible, at least with the centrifugal bolt that is on my bow. Been at it for over an hour and every time i have the string running trough the middle of the riser the limbs are of, when i then adjust them to to run straight its all back to zero again. I i think i"ll be staying at the club all night....... :|

 

Thanks a lot for this, great way to check where is the middle instead of eyeballing....

Immediately went down to the garage after reading this to check my bow, never thought that factory set up GMX would be off from center to the right with about 2 mm.
Adjusted now to center (after needed to adjust plunger and sight too....), groups tightened vertically a lot!

Thanks again.

 

never thought that factory set up GMX would be off from center to the right with about 2 mm.

Where on the GMX did you use for measuring off of? The best place I found was the rounded section around the main stabilizer bushing, but that seems unreliable.

As far as I could measure, my GMX seems spot on from its factory settings, but I'm not sure that that means I'm doing it correctly.

-T

 

I mean eccentric bolt

 

turns out my riser doesn't have a single spot where it is symmetrical and straight enough to to lay a bow square on. Even underneath my grip the aluminium is malformed, like it's been cast but they ran out of molten aluminum so it left a big gash and a wobbly appearance... Pity I noticed this only 4 years after I bought it.

 

How about replacing temporarily limb bolts locking grub screws with bolts long enough to almost reach the string, and see if it centers? Well, you actually do not have to remove locking grub screws. Just turn in the long enough threaded rod into the limb bolt hole.

GM

 

Seattlepop, Thanks for the "assist" on this one! Great photos btw.

Just got home from a 300 mile trip with my daughter to teach archery to some college students at my alma mater. They left hoping they could someday shoot as good as the 11 year-old I brought with me! ha, ha. Good day, but we're exhausted now.

John, are you saying you can use beiter limb gauges and get your string tracking thru them perfectly, but still not have the bow on plane?

Kenn, this is exactly what I'm saying, and it's more common than not on bows I look at.

Also what do guys do that shoot non adustable risers, like the Best Moon or others?

Easy. Get straight limbs and then never worry about a thing after that...

you are aligning the limbs thru their centers and then laying them both over evenly until the string is tracking thru the center of the riser, not the center of the limbs. You have found this to be more accurate/forgiving then leaving them "in line" and adjusting the plunger in/out? Hard to argue with your success, just hard to get my head around.

If you have alignment adjustment, there will always be a way you can align both limbs AND the plane of the riser at the same time. That's what you want.

John

 

If you have alignment adjustment, there will always be a way you can align both limbs AND the plane of the riser at the same time. That's what you want.

John

"If" you could align the limbs and then move them left/right without changing thier relationship to each other, then and only then could you align them to the plane/center of the riser. However as pointed out you cannot move the limb bolts, so this is not possible. John I suspect the limbs you have been working with have not been that far out of spec. I had a set of limbs I bought one time that were so out in left field there was nothing that could be done with them. I had to send them back. The bennefit I see from ensuring the string is down the center of the riser is less side torque that would be implied. One has to determine the trade off between limbs that arent aligned, but the string is tracking down the center, or have the string track true with the limbs and have the string possibly be slightly out of plane. Im sure many get lucky and have it work out perfectly, but I suspect many dont even check limb alignment. Interesting subject John. I have never measured as you have here, but have penciled a line/mark on my riser when I had that set of screwed up limbs to see what was going on.

 

I would think that rather than trying to find the perfectly parallel sections on opposite sides of the riser, you could just visually align the string down the centers of the limbs AND through both of the limb bolts. Or am I missing something with that simplification? That's how I've always done it, and now I'm wondering if it's insufficient.

 

I got rid of Beiter's limb gauges long time ago. If I have to pick measuring center plane versus eyeballing with my eyesight.. I prefer measuring method. :wink: With beiters I could line up gauges, limb bolts, string and still was 2mm off plane.

GM

 

I don't know about all this stuff, but I sure want one of those red bow squares!!!!:jeez:

 

Yup, that's an easy one there. Some risers, esp. the carbon ones, have few flat surfaces to use and get a little more tricky.

All reasons why I appreciate what PSE did with their X-appeal. You don't even need a bowsquare for their handle. Just lay an arrow in the groove and look!

John

 

All reasons why I appreciate what PSE did with their X-appeal. You don't even need a bowsquare for their handle. Just lay an arrow in the groove and look!

And thinking more along those lines I came up with this: Put an arrow on the rest, adjust button to set arrow centershot, put another arrow on the inside of the window and check if both arrows run parallel, looking from behind the string.
This would show if the riser was "on plane" (giving the sight windows is flat and straight) or not, wouldn't it?

 

let me try and explain what i was getting at.
A riser can be twisted in 2 ways, and both with show up like this:

so to get a limb lined up nice you would wind the limb over on the adjusters.
but in this particular example this would be wrong.

one limb pocket was rotationally out. This means that the limb leaned over and needed propped up rather than shoved over.

We have seen risers where both limb pockets were inline with each other, but were rotationally not square to the riser.

This means to achieve the measurements your trying for here, the limbs would both have to be twisted out of thier natural tracking.

What im saying is that the pivot point, and limb pads need to be all on the same axis, same plane, and inline. so that the limbs track straight. and the bow is not banana'd to the left or right.
This would casue pull and release torque if not straight.

The faces of the riser, can wobble left and right, as long as the pivot point is inline with the plane of the limb pull direction.
I think thats what your trying to achive, but the faces in my view cannot be trusted, since it can throw the limbs out of tracking.
they would show up like the first picture.

(does that make sence)