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How to fix cam rotation problems!

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Cam rotation problems can cause big problems with nock travel and good arrow flight. A lot of the bowhunting writer's call these bows with this problem "Untuneable Bows". Most of us have had a bow like this. You tried everything to fix the bow from nocking loops, different arrow spines, months of paper tunning, different arrow rests, and nocking points with the same problem. No matter what you do you get a nock high or low in paper! You ask the maker of the bow and they don't really know why but think its you not the bow. The fact is its the bow!! This is how you can fix that bow!
Note: Cam rotation is not the same as Cam lean! That's a different problem and can be fixed by the split "Y" of cable, new bushings or adjusting and replacing cable slide.

Step # 1

Before you start twisting the string and cable for cam rotation. Move the nock or loop up and down the string to see if it helps you get a bullet in paper. If it has no affect then follow steps below.

Click on picture for larger view!
loopnockingpoint.JPG

Before we start the twisting of the cable or string for cam rotation its important to try a nocking loop that is set up like the picture on the side. This may fix the problem without having to play with the string or cable. Adjust your loop so its under the arrow not in the middle this may fix the problem and give bullets.

Click on picture for larger view!
brassnockingsetup.JPG

If you don't use a nocking loop then you can use two brass nocks or tie in nock under arrow like the picture on the side. Make sure to have a small space so nock is not pinched at full draw. Pull under the brass nocks or tie in nocks.

Step # 2

limbboltadjustment.jpg

If the nocking loop or nock set up doesn't work then the next step is adjusting limb bolts. If you are getting a nock high in paper then take off 1/2 turn on the top limb bolt and level the nocking point. It should have moved so level it up. If you are getting a nock low then take a 1/2 turn off the bottom limb bolt and reset nocking point so its level. The combo of step 1 and 2 can sometimes give bullets and good arrow flight.
You may need only 1/4 or full turn on limb bolts. If you get a bullet with these adjustments your good to go. If you don't see any changes then its time for twisting string or cable for cam rotation. Don't go more than a full turn on limb bolt if you don't see any changes in paper tear.

Step #3 Cam Rotation

Mathews Cams have timing holes for cam rotation.
camrotationright.JPG

Now that you have tried step #1 and 2 without any luck reset limb bolts so its back to the start or at factory setting. Solo cams are normally just bottomed out and Hybrids are set even tiller. Some solo cams and Hybrid cams have timing marks on cams to show the proper rotation. These marks are not always right. The best way to find the right rotation is paper testing. The picture on the side shows the timing holes on a Mathews cam. Solo cam bows that use mods can cause alot of problems and change nock travel bad. Paper testing is the best way to find proper cam rotation.

Click on picture for larger view!
camrotationpapertest.JPG
More information is at bottom!

Click on picture for larger view!
underrotatedcam.JPG
Under rotated cam!

Set your bow up so the rest and arrow is level.  Paper test bow. If you get a nock high tear the cam is under rotated so add 6 twists to the cable and level nocking point. Test again. If your tear is getting smaller continue adding twists and leveling arrow until you get bullets. 

Click on picture for larger view!
overrotatedcam.JPG
Over Rotated Cam!

If you are getting a nock low tear in paper then your cam is over rotated. You fix this by adding 6 twists to the string. Reset nocking point so its level and test again. If the tear is smaller then continue to add twists and level arrow until you are getting bullets.

If rotating the cam gives you bullets then your good to go. Some cam designs you can't fix by rotating cam because the problem is in the cam design and rotating the the cam won't work. The cam doesn't let out the right amount of string on the string tracks or the mods for draw lenghts affects the amount of string that is let out.  Step #4 is the last thing you can do to fix the problem.

Step #4
 

Click on picture for larger view!
4inch3inchwheels.JPG

If step #1, 2 or 3 doesn't work then your at the last resort. The last thing you can do to fix your bow is to change the size of your idler wheel. If you are getting a nock high tear in paper change from a 4 inch idler wheel to a 3 inch idler wheel. You will have to change the string lenght to match new wheel. This changes the string angle to get bullets. If you have a nock low tear then change from a 3 inch wheel to a 4 inch wheel. You will have to change string lenght to match larger 4 inch wheel. These should be a last resort. If this doesn't work contact me. Thanks Mike

As you can see making changes to your equipment can change the angle of the string at release and produce bullets in paper. Moving limb bolts, rotating cam or changing idler wheel can change the angle of the string in relation to the bowhandle for good arrow flight. That's why it is so important to use a good string and cable to keep the cam in proper rotation for good arrow flight. Installing STS systems can affect this angle and can fix the problem also and can cause a problem if installed wrong. If you have any questions just use any of the comment boxs. Thanks Mike
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