# 2015 Nitrum Turbo Cam Lean



## Jefnmichele (Mar 28, 2015)




----------



## TMan51 (Jan 25, 2004)

Well, there are several ways to get a shaft to leave the bow correctly, and most of the adjustments can be taken over the edge in an attempt to get things flying correctly.

Myself, I use cam lean/yoke adjustments at the end of my adjustment strategy, as it's best, in my experience, at small adjustments and fine tuning. Visible cam lean is not a good thing as it implies an angular force, a vector, that is not in alignment with the string running in the track of the cam. In a worst case scenario that can actually jump the track on a shot.

I think the most accepted practice is to start with a cam that gives you proper alignment with the string in the same plane as the cam, and the entire string/cam/riser center of mass and center shot and shaft all in the same plane as the pins on the sight. Most of the adjustments to alignment will go forward from there, and unless you have a bum limb, which can happen, the actual magnitude of any single adjustment will be tiny. I have eight Hoyts, and they all have nearly 100% of those properties without touching the cam lean at rest. Yoke tuning is taking that level of setup, and compensating for very small amounts of lean at rest or full draw that are actually very hard to even see in most cases.

I do use bare shaft tuning to get the rest and sync set, and I use the nock position and shaft height to the Berger hole in the mix, but those adjustments are so slight they are actually hard to see. Visible cam lean is an indication of a mechanical problem corrected by a bone head tech.


----------



## KYOWA (Jul 10, 2012)

First if I am right that is a right hand bow, if so put the arrow on the other side of the cam and then see how far the tip of the point crosses over the string out the nock point. It shouldn't be no more than 1/8 from center of string to center of point.


----------



## Jefnmichele (Mar 28, 2015)

KYOWA said:


> First if I am right that is a right hand bow, if so put the arrow on the other side of the cam and then see how far the tip of the point crosses over the string out the nock point. It shouldn't be no more than 1/8 from center of string to center of point.


Thanks to both for the replies. When I place the arrow on the left side of the cam, the tip of the arrow is 1/2 inch from the string at the nock.

The cam lean is extreamly noticeable at rest. So much that the bow hangs at an angle on my bow stand. I had the shop install the smack down pro, before they tuned my bow. I ask the original questions because I thought the rip I had during them paper tuning, could have been corrected with the rest and the nock positions.

I know next to nothing about tuning a bow like this. But it doesn't seem right.

Hoyt returned my email after looking at the photos and said, 

Jeff,
Thank you for the pictures. I discussed your set up with our Engineering Manager and here is a summary of his comments:
· The buss cable twist rate is surely acceptable. This is a common practice for fine tuning Cam & ½ bows.
· The Nitrum Turbo is a bow that likes to tune inside. Meaning the arrow is a little to the inside of center shot. This is also not a problem, it just where the bow likes to shoot and as best we can tell from the pictures, your rest is inside but not out of tolerance.
· As I said, cam lean in the right direction is preferred. This is in part due to the way that the cables are angled and the way that they rest in the cam at the end of the shot cycle. From the pictures, your cam lean is probably close to our limit but certainly acceptable – especially given the fact that you get a good paper tear.
I hope this helps. Please let me know if you have further questions.
Best Regards


----------



## Jefnmichele (Mar 28, 2015)

Something I forgot to add, when my wife purchased this bow for me, I wanted the camo. The shop tried to switch the cams from this bow, to the camo bow to get my dl and 70lbs I requested. The tech called me to say that the cams from the black bow, would not work on the camo bow. I didn't understand it then, and understand it even less now. Nitrum turbo black bow cams won't work on a nitrum turbo camo bow? I just remembered this conversation...


----------



## TMan51 (Jan 25, 2004)

Jefnmichele said:


> Nitrum turbo black bow cams won't work on a nitrum turbo camo bow? I just remembered this conversation...


Unless something truly unique has happened to Hoyt bow/cam designs, the tech is full of poo. I've switched and swapped cams on dozens of Hoyt bows. The process is very straight forward as long as the recipe for riser and cam combinations are correct. The fact that it won't sit straight due to limb alignment means you have some uneven stress and shear that needs to be corrected.

Do you have access to a decent press? Like most of the top end designs from anyone, the Nitrium is highly stressed, to the point that peak weight is limited to 70lbs. You really want to be careful to avoid any bow, or worse, shooter damage.


----------



## Jefnmichele (Mar 28, 2015)

TMan51 said:


> Unless something truly unique has happened to Hoyt bow/cam designs, the tech is full of poo. I've switched and swapped cams on dozens of Hoyt bows. The process is very straight forward as long as the recipe for riser and cam combinations are correct. The fact that it won't sit straight due to limb alignment means you have some uneven stress and shear that needs to be corrected.
> 
> Do you have access to a decent press? Like most of the top end designs from anyone, the Nitrium is highly stressed, to the point that peak weight is limited to 70lbs. You really want to be careful to avoid any bow, or worse, shooter damage.


I sure don't. Wish I did, I would undo what he did and start over on my own. The cam was straight, before he paper tuned it. Once he saw the rip high and to the right, I think I might have said left before, he went right to the buss. Tightened it once, still high and right rip, tightened again, bullet hole. Not sure how many twists he put in it. Looks like a lot. 

Going to try a different shop, get a second opinion so to speak. The cam not switching over eludes me. Cams don't care what color the bow is. I won't be back there again. The response from Hoyt was a bit concerning as well. 

I will let you know what I find out. If I go back to even on the buss cables, what would be your first move to fix the high right rip? Correct the vertical first then the horizontal? 

Thanks!


----------



## TMan51 (Jan 25, 2004)

Jefnmichele said:


> If I go back to even on the buss cables, what would be your first move to fix the high right rip? Correct the vertical first then the horizontal?
> 
> Thanks!


Assuming timing for DL and synch are on, I check to see if the string, riser center of mass, sight and shaft are all in the same plane. Then I go back and forth with nock orientation on a bare shaft, I don't do either all at once, as they are interactive to a degree. I also don't try for perfection in a single session. Each adjustment needs to settle in, otherwise you're chasing that "settle in effect", and can easily overshoot the sweet spot. Some shooters need to use the window for shaft height over the rest mounting hole, but leave that for last.

Yoke tuning is a last resort or final polish.


----------



## Jefnmichele (Mar 28, 2015)

Thanks TMan. I called another local shop and the guy was kinda bent that I didn't buy the bow from him. said he would take a look. problem is he and I work the same schedule.


----------



## KYOWA (Jul 10, 2012)

You have more lean in yours then I do my nitrum turbo, I have half as much but the arrow you choose can make a difference in the lean. If he couldn't change the cams on the two bows they where different cam sizes, the limbs on a #1, #2, and #3 all three 70lb have a different deflection, I am guessing that's wy he told your wife he couldn't change the cams.


----------



## TMan51 (Jan 25, 2004)

KYOWA said:


> I have half as much but the arrow you choose can make a difference in the lean.


I'd be interested in the theory behind that one.

I currently have eight bows hanging in my collection, four different cam variations, (somehow), and none of them have any significant lean at rest. They all have little or no upper cam lean at full draw. I find that once the bow is setup, starting with zero lean at rest, most, if not all of the fine tuning can be accomplished without touching the yoke adjustments. When the yoke tuning plays in, it's usually a matter of a problematic nock lean at 20-30ft,or a BH that just won't quite land at the point of aim. Sometimes I suspect it's compensating for a small amount of lower cam lean.

I learned that over many years of tuning and setting up my own equipment, and the bows of friends and family. I've owned a bench mounted bow press since the early 90's, and they get a lot of action. I have utilized yoke tuning for a much shorter interval, and it does solve some quirky tuning issues, where things do not tune at center of mass. What I have not seen, is the upside to a significant amount of lean. I picked up a Vector 32 a while back, 2012, that just would not tune. I broke down and took it to a shop that had the same results. I found I could eliminate a problem with left POI with an atypical amount of cam lean, but I couldn't get rid of left flyers. I had a bum limb in the mix, and a second set of limbs took care of the problem immediately.

You can get acceptable flight with visible lean, but in my experience, bows shoot the best without a lot of lean.


----------



## KYOWA (Jul 10, 2012)

In most case's the stiffer the shaft the less lean needed. And I would find it hared to believe that all shafts of the same spline are the same, so I could see a difference in lean from one shaft to the other of the same spline. If a bow has a cable slide there will be no need for cam lean at all. I have been tuning bows for 32 years and can tell you that know one can get a new Hoyt with a roller guard to put a full size fixed blade in the same hole as a field tip with out some lean at long range.


----------



## BowKil (Mar 19, 2005)

kyowa said:


> in most case's the stiffer the shaft the less lean needed. And i would find it hared to believe that all shafts of the same *spline* are the same, so i could see a difference in lean from one shaft to the other of the same *spline*. If a bow has a cable slide there will be no need for cam lean at all. I have been tuning bows for 32 years and can tell you that know one can get a new hoyt with a roller guard to put a full size fixed blade in the same hole as a field tip with out some lean at long range.


 ..................Spine.............


----------



## Jefnmichele (Mar 28, 2015)

So finally got to a press. Took all but one twist back out of the upper left control cable. Sorry if I call it wrong, just learning the new bows. Shot it at paper, got a small tear right. Moved the rest about a 1/8 inch. Bullet holes. 

Bow feels right again. Thanks for all your help!

Jeff


----------

