Fixing Compound Bow Cam Timing Problems

by MS.com staff on August 26, 2011

By: Steve Helinski

Just can’t seem to fix that bow that is tearing nock high or nock low? No matter where you move your rest or nocking point you are still ripping the paper up pretty bad vertically?

Well your problem, as I found out this year could be unevenly timed cams if you have a two cam bow, as I found out this year.  You will need to learn how to fix bow cam timing problems.

How do you tell if your cams are not turning over at the same time. Well the answer in short is visual inspection. The easiest place to pick up on this is when your bow is at full draw. Draw you bow back as far as it goes then let it down slightly and go back to full draw. Watch both cams as you do this and make sure they flip over at the exact same time. If there is even a slight difference it could be causing your headaches.

You will need a full bow press or one of the portable ones available to fix this problem. Since I didn’t want to spend the money on a full blown bench bow press, I bought a portable one which I can also take with me on hunting trips to fix the odd problem that comes up, or to replace a string. I bought The Lapper made by Game Tracker.

bow press

Figure 1 Shows the press between the two axles of the bow in the compressed position with the weight off of the string.

bow press in use

Figure 2 Shows a closeup of the tightening mechanism of the press in the compressed position.

bow press on axle

Figure 3 Shows a closeup of one of the bow axles and where the bow press fits into the crotch of the bow limb.

So what do you need to do to fix the problem? Well make note of the cam that was not turning all the way over when you had the bow at full draw. After you get the bow press on and the string relaxed, you will have to take the “yoke” off of the end of the bow that had the cam not turning all the way over. The ‘yoke” is the part of the string that splits into a Y at the very end of the bow limb as shown in figure 3 with the orange pointer.

Take the yoke off both sides of the axle. You will then need to twist the piece of string that is attached to the yoke and put some extra twists in it in the same direction that the string already has twists in it. This will shorten things up on this axle and hopefully cause this cam to achieve full turnover at the same time as the other. Start out with a few twists and then go through the process again as needed.

paper tuningt a bow

Figure 4 Some nice tears through paper with a broadhead.

When you get all done this is what your paper tears should look like. These arrows were shot from 20 feet with a broadhead on. Now you have achieved bowhunting Nirvana. Having trouble telling which cuts were made by your broadheads and which were made by the vanes? Put some lipstick heavily on the broadhead before you fire it and this should clear up the picture quickly.

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