Archery Talk Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
943 Posts
Discussion Starter #1
I know what Cam Lean is, but why is it done and what's it's benefit? Thank you!

Sent from my SAMSUNG-SM-G870A using Tapatalk
 

·
Registered
Joined
·
3,973 Posts
Purposely inducing lean to one side or the other is done to mitigate uneven amounts of torque on the limb tips from pulling the cables to one side. Usually there is cam lean somewhere in the draw cycle if the bow is tuned properly (unless the manufacturer tries to account for it by installing different deflections on their limbs.)

Last time I tuned a bow with yokes (same limb deflection on both sides) I ended up with a 30 yard bareshaft tune and the top cam started like this \ and went to this at full draw /. So I ended up splitting the difference during the draw cycle.

Every other bow I've tuned I stopped paying attention to the lean and just focused on the tune.

Sent from my Moto G (5) Plus using Tapatalk
 

·
(aka lug nut)
Joined
·
49,610 Posts
I know what Cam Lean is, but why is it done and what's it's benefit? Thank you!

Sent from my SAMSUNG-SM-G870A using Tapatalk
Cam lean is yoke tuning. Cam lean is also shimming a cam sideways. If you have yoke legs, when you yoke tune, you are fine tuning cam lean. Basics. Left paper tear, shorten the left yoke leg a twist. If you need more adjust more, then remove a twist from the right yoke leg. Yoke tuning is tweaking the cam lean, which is twisting the limb tips on purpose, to steer the cam, to point the aimstring, the bowstring push direction slightly more left or slightly more right. A left paper tear, means the nock of the arrow is ripping the paper to the left, which means the pointy end of the sharp stick is flying off to the right. Want to steer the arrow more LEFT? YOke tune the left yoke leg shorter, and YOKE tune the right yoke leg longer. This torque/twisting of the limb tips, will FORCE the cam to point more to the LEFT. YES, when you lean a cam to the left, you are also changing the compass direction for the push of the bowstring, more left.
 

·
(aka lug nut)
Joined
·
49,610 Posts
I know what Cam Lean is, but why is it done and what's it's benefit? Thank you!

Sent from my SAMSUNG-SM-G870A using Tapatalk
What if you don't have yoke legs? What if you have a binary cam bow, with no yoke legs? Well, to fix a left paper tear, you SHIM the cam left. What does that mean? When you stand behind the bow in firing position, the LEFT side of the top axle is on your LEFT. So, press the bow, pull off the axle, remove the cam spacer on the left side, and put in a more skinny cam spacer (shim) on the left side. Say a cam spacer (shim) that is 0.010-inches more skinny. Then, you need to put in a cam spacer (shim) that is 0.010-inches wider on the right side. What does that do, when you SHOVE a cam more to the left? The angle of pull for the cable, will now LEAN the top cam, more left. Who cares about cam lean? It works.
 

·
Registered
Joined
·
8,997 Posts
When you have a binary cam bow with a right tear and no further space to shim to the right, then you live with it.
 

·
(aka lug nut)
Joined
·
49,610 Posts
When you have a binary cam bow with a right tear and no further space to shim to the right, then you live with it.
Nope. There are other options. I have a binary cam bow, with a right tear. I decided to experiment and do ZERO shimming the cam. I shimmed the top left split limb.



I also changed the angled cable guard, to a standard teflon cable slide, to increase the pull on the cables to the right.



The angled cable guard is like a tilt tamer. So the stock cable slide has very very little sideways torque on the cables at full draw. To kill a RIGHT paper tear, for a RH bow, you want the cable slide to pull HARDER on the cables, when at full draw. The standard teflon cable slide pulls the cables to the RIGHT at full draw, which induces the top cam to lean LEFT more than the angled cable slide.



3/4-inch right tear with the bow BONE stock. Switching from the angled cable slide to the teflon cable slide, dropped the right tear to 1/4-inch. Shimming the upper left split limb, dropped the 1/4-inch right tear, into a bullet hole.



How do I know that the issue is not my form or my grip? Used a shooting machine to diagnose the problem, and the fixes.

 

·
Registered
Joined
·
8,997 Posts
I have used angled rods that would move the cables into the sight and it would not correct the problem.

I don't shoot good enough anymore for it to even matter.

I think the bow shot better when I set the angled rod up so that it moved the cables away from the riser instead of moving the cables closer to the riser. It has been a long time since I did any tuning on the bow. I just shoot it and have fun.
 

·
Registered
Joined
·
825 Posts
saving for later-great info
 

·
Registered
Joined
·
8,431 Posts
Cam lean adjustment is to move the string path left or right in order to get it precisely behind the arrow.

We move the rest left or right for the arrow to chase the string path.
We move the string path left or right for the string to chase the arrow.

Best tune is accomplished with everything running down the center of the bow. Set the arrow to the center, then tune the string path to put it behind the arrow.

Obviously there is a lot more to it. Hopefully this answers your question.
Allen
 

·
Hunter of many things
Joined
·
12,154 Posts
In simple terms: after you set your rest position and you still have a paper tear (L or R), you need to lean the cams to get the string behind the arrow. When its directly behind the arrow it sends the arrow flying straight out of the bow straight. WHen its not, it sends it flying sideways (for lack of a better term) so the vanes need to do all the steering to get it flying straight again.
 

·
Registered
Joined
·
5,434 Posts
I know what Cam Lean is, but why is it done and what's it's benefit? Thank you!
Cam lean isn't something you do and there is no "benefit" to it. It is a negative byproduct of having a bunch of unbalanced forces being restrained by a set of strings and cables.
Usually caused by having limbs that are not the ideal stiffnesses with respect to each other on the bow; or by not having the cams located in the ideal spot on the axles (shim locations).

The ideal scenario is have all the forces balanced perfectly such that there is no cam lean at brace or at full draw with the cams staying straight during the draw (no nock travel in either direction).

By yoke tuning you can manipulate the forces such that the nock travel path aligns with the arrow rest position.
When this is done you are not really "adjusting cam lean"...you are modifying the bows nock travel path (power stroke) to align with the arrow.
If the forces are too unbalanced you often have to shim cams or move limbs around.

Just me 2 cents for what its worth...
 

·
Registered
Joined
·
8,070 Posts
Cam lean isn't something you do and there is no "benefit" to it. It is a negative byproduct of having a bunch of unbalanced forces being restrained by a set of strings and cables.
Usually caused by having limbs that are not the ideal stiffnesses with respect to each other on the bow; or by not having the cams located in the ideal spot on the axles (shim locations).

The ideal scenario is have all the forces balanced perfectly such that there is no cam lean at brace or at full draw with the cams staying straight during the draw (no nock travel in either direction).

By yoke tuning you can manipulate the forces such that the nock travel path aligns with the arrow rest position.
When this is done you are not really "adjusting cam lean"...you are modifying the bows nock travel path (power stroke) to align with the arrow.
If the forces are too unbalanced you often have to shim cams or move limbs around.

Just me 2 cents for what its worth...
Best answer in this topic.
 
1 - 19 of 19 Posts
Top