CaMirror™
 

I thought I had my new Admiral's cams sync'd pretty well, using several methods. Landmarking the cams with the limb surface. Landmarking the cables with the draw stop post at full draw. Taking the cables out of the roller guard and counting dots on the cams... .
Then I thought about the radius I was looking at, between the cables and the limbs/dots and thought," if only the radius was larger than the 2 inches or so that I'm looking at?" That's when the idea came to make a fixture that would fit precisly on the cam so that a pointer could rest on a common point (the string) , relative to both cams. It had to be repeatably accurate and adjustable. I made up a prototype and checked it on all my bows that had mirror image cams, Binary and dual. It worked very well and also showed me quickly how far off the cams were in relation to each other at brace. My Admiral that I thought was dead nutz on was actually off by 1/4 inch at the pointer, which now gives me a reading 11 inches away from the axle centerline. That's 5 times the accuracy that I normally have to work with, with a 2 inch radius.
On my Patriot and Pro 40 Dually I also got a suprise! Both were so close that I don't think I could justify going to the extra work to make them perfect,, at more than 11" radius. The last time I shot both these bows they were perfectly in sync at full draw also. It would also be easy enough to purposely to advance one cam ahead of the other if you knew where you wanted to tune your bow. With the much larger radius it is so much easier to see;)

Here's a pic of the first prototype:D

RE: CaMirror™
 

That was the bottom cam on my Admiral, here's the top cam and the difference at the pointer.

RE: CaMirror™
 

The replacable pegs fit inside the cutouts of the cams and adjustments can be made to fit precisly. On smaller cams or cutouts, the "top" peg can be used while simply resting on top the string while in the cam groove with the same accuracy.

RE: CaMirror™
 

Russ, that's a great jig you've made there.
Were your tiller measurements the same with the cams that out of sinc?

RE: CaMirror™
 

Yes the tiller is the same. Keep in mind that though it shows a 1/4" difference, it's "magnified" with the increased radius of the pointer. It's the difference I couldn't see while referencing the cables at the cams and within that radius.

RE: CaMirror™
 

Looks like I forgot to post the picture I wanted in post#3[&:]

RE: CaMirror™
 

Gotcha. Would be intresting to see thecam sync at full draw on a draw board.Can you try that using the jig. I'm thinking here a test to show how equal the limbs are in poundage with the cams fully sycronized.

RE: CaMirror™
 

That could probably be done if the string was pulled in the exact center instead of the normal nocking point. If pulled from the normal nocking point, the string angles are different and would show different reference points with the CaMirror even though the cams are in perfect sync at full draw.

RE: CaMirror™
 

I guess then it would not be as easy, mainly because the grip is not in the center of the riser, so you will pretty much have to brace the bow above the grip to get the string angles to match.

RE: CaMirror™
 

I've checked both of my Duallys with the tool and they were both suprizingly very close at brace. Drawing the bows I couldn't feel the usual double bump at full draw that indicated the cams are out of sync. I don't think it would be wise to use any tool on the cams at full draw, even in a crankboard;)