Nitrous X set up problem
Just bought my first Martin bow (06 Shadowcat Nitrous X) a few days ago because of the zero torque characteristics of the X-system. I've encountered a small problem setting it up, though.
I have the narrow axles, which don't give me enough vane clearance (1/32"), even with 1.5 inch Blazers on skinny carbon arrows. So I picked up some Barnsdale spreaders -- awesome little gizmos.
But a strange thing happened after I installed them. Before putting them on, I double checked my cam lean by pressing an arrow up against the cam. The arrow and the bowstring were perfectly parallel when I checked both cams.
After I put the spreaders on I checked my cam lean again, and the arrow slanted toward the string from the top cam. The slant was the equivalent of being about 1/2 twist off. Stranger still, the bottom cam was still perfect.
So then I switched the spreaders around -- put the one I had by the top cam by the bottom cam, and vice versa. Same thing: bottom cam alignment was perfect, top cam was off the equivalent of a 1/2 twist.
Any help figuring this out would be greatly appreciated.
I'd say get the longer axle kit from Martin, but you already have the Barnesdale spreaders. I'd say don't try to over think things. If you need to put a half twist or even a full twist in one cable by all means do so.
Thanks for the reply -- I'm going to get the wider axles.
I tend to agree with bfisher. I don't think it is that big of a deal if the cam lean is a little out.
However, It is sort of a puzzler at the same time. This is one of the troubles with the shoot through system and one of the reasons, I started making my own cables and strings. The cables have to be perfect in length or you have all sorts of problems trying to get this true linear nock travel. I would guess, the reason the spreader even when switch is creating the same cam lean is probably not in the spreaders, but is in a slight difference in cable length which is not apparent without the spreaders. There will be a slight increase in poundage and draw length when you install these spreaders without increasing the cable length.
I have found you can really get these bows to shoot however, with bare shafting and walk back tuning. I only pay real close attention to the cam lean on the initial setup. Then you need to establish a center shot and this is probably best done with a walk back, first. Then I would work on the cam lean or lack of it with bare shaft tuning. Then I would do another walk back until there is no further adjustment required to the rest or cams.
I guess, what I am saying you don't have a real bench mark and you have to determine by these two methods, if the center shot or the cam lean is interfering with the true arrow launch, you are looking for.
I set up center with a straight edge along the riser and line the windage of the sight up between the splits in the limbs. As long as the riser is straight with the pockets and limbs straight in the pockets that is where it's going to shoot without operator error.
Anything beyond that is me and I work on the problem. I do the same with rifle scopes and set them with the rifle in a vice.
Unless you're really crowding the arrow with the lower spreader I don't see how anything is gained with them for arm clearance. Your arm is amost in line with the arrow. And if a spreader rubs your arm I would think it would be prone to twisting and closing the gap on both sides of the arrow.
My guess for the spreaders changing lean but not in a way that it could be machining differences is that the way you put them on consistently torques that one cable. Whatever process you use to put them on try doing it reversed. If you do it in your lap or vice turn the bow around so the top is now in the position the bottom was in. If the problem switches you know it's you.
Bingo. When you slide the spreader up or down on the serving, you can see the cables twisting like a barber shop sign. I'll give it one more try, but Deezlin has very kindly offered to send me his longer axles, so that's the route I'm going.
Originally Posted by Myk
You know, you're getting some decent advice here and I just took note of what Myk was saying. It's just a thought, but when the cables are put on the spreader they may not be centering real well. causing the cam lean. However, they may do so from the vibration of shooting the bow. Please help with this. I think I'm learning something from you guys.
They know their stuff, that's for sure. I always read their posts on AT.com and pick up all kinds of great insight from them.
I'm inclined to think that the spreaders will not move during the shot, or after. I've never taken a shot with them on, though, because they (or the way I was installing them) were causing that little bit of lean at brace, and there is no way I'm shooting this bow if it has any visible lean in it at brace -- the zero lean/torque feature of the X-system is the whole reason why I'm a Martin guy now.
Anyway, I'm sending the spreaders to Deezlin. He prefers the spreaders over the wide axles, and he's using the Genesis spreaders at the moment, which don't have the snap on feature of the Barnsdales. He may well be able to succeed with these things where I failed, so you might ask him to PM you once he's given them a test run.