# cam&1/2 timing



## Drtumolo (Jan 19, 2003)

Could someone give me the link to Java's procedure on timing the cam&1/2? I can not seem to find it with the seach feature.


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## JAVI (Jun 19, 2003)

http://www.archerytalk.com/vb/showthread.php?t=207391


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## bumper (Aug 27, 2004)

This might help.


Here is a part of my tuning guide....


Hybrid Cam Sync & Timing 
By Mike Javi.... Cooper



The timing system on the hybrid cams is somewhat different from other systems.

The cams need to be in synchronization and in draw stop timing; these are two entirely different issues but interconnected. It is possible to have the cams in sync, but not in time and visa versa. 

The string is for all practical purposes, just along for the ride, the buss cable (yoke) controls the bow, and it is used to set the axle to axle (limb) preload and takes most of the weight of the limb deflection at full draw. The control cable (slave) ties the two cams together so that they rotate at the required speeds. 

The reference marks or holes (depending on the cam) are there to provide a visual reference to cam synchronization not draw stop timing. I find that tiller is a more precise indicator of cam sync; if the limbs are bottomed out the tiller will reflect the position of the cams better than the reference holes (marks).

To adjust the cams, I back the string off until I’m sure it isn’t affecting the axle to axle (usually ten twists will do) then adjust the buss cable to bring the axle to axle measurement to a ¼” longer than the specifications for that particular cam/limb combination (see Hoyt tune charts). The control cable should be used to sync the rotation of the cams while doing this. If the cams are in sync at this point the reference holes will be equidistance from their respective cables and the tiller will be even (limbs bottomed out). 

Now is the time to adjust the draw stop timing, using a draw board or similar device (you can draw the bow and have someone else look at the cams) when the bottom cam’s draw stop is just touching the buss cable, the control cable should lay flat in the groove of the top cam. If the cam is under rotated you can put a twist in the buss or untwist the control, I determine which I do by the draw weight and draw length of the bow. Shortening the buss cable will lengthen the draw and increase the draw weight. Shortening the control cable will decrease the draw length and decrease the draw weight.

At this point, I measure the draw length (using AMO standards); it should be long and the draw weight should be higher than spec for the bow. I will then twist the string to bring the draw length to spec; this should also bring the draw weight and axle to axle into spec. 

I double check everything and tweak a half twist here or there to fine tune it. 

Finally I use the hybrid cam creep tuning method to set the bow to my shooting style.

If you follow this method you will have a very solid wall and the bow will be practically vibration free.

A note: the regular cam & ½ should be tuned in the “D” draw length slot for best performance. You can then set the module to your required DL and tweak the DL using the string.


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## Drtumolo (Jan 19, 2003)

thanks


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## Drtumolo (Jan 19, 2003)

*still need help*

I followed the above procedure to adjust the cam sync and the draw stop timing. If I adjust the control cable to sync the cams (I have the cables falling in the middle of the refrence marks) the draw stop timing is way off. (the upper cam is under rotated) After I adjust either cable to time the draw stop timing the lower refrence marks are equal distance from the cable but the top cable is right on the inner refrence mark. Does this mean the cams are again out of sync? 
My problems all started when I had new winners choice string and cables put on my bow. The bow shot a perfect bullet hole through paper with the old strings(easiest bow I ever tuned) but when I tried to tune it with the new strings I get a tail high tear. No matter what I try with moving the nock point or the rest it still tears high. I then tried shooting bear shafts at 10 yards and they all hit tail high. That is when I stumbled onto the thread about timing the cam &1/2. I thought that would be the solution and that is how I got to were I am at now. Any ideas????


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## JAVI (Jun 19, 2003)

Drtumolo said:


> I followed the above procedure to adjust the cam sync and the draw stop timing. If I adjust the control cable to sync the cams (I have the cables falling in the middle of the refrence marks) the draw stop timing is way off. (the upper cam is under rotated) After I adjust either cable to time the draw stop timing the lower refrence marks are equal distance from the cable but the top cable is right on the inner refrence mark. Does this mean the cams are again out of sync?
> My problems all started when I had new winners choice string and cables put on my bow. The bow shot a perfect bullet hole through paper with the old strings(easiest bow I ever tuned) but when I tried to tune it with the new strings I get a tail high tear. No matter what I try with moving the nock point or the rest it still tears high. I then tried shooting bear shafts at 10 yards and they all hit tail high. That is when I stumbled onto the thread about timing the cam &1/2. I thought that would be the solution and that is how I got to were I am at now. Any ideas????


Yep... ck your pMs and call me..


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## robbo (Oct 15, 2002)

I have just put a Vapour Trail string with the split harness, on my sons Sierratec.

Is it better to have the floating harness, or are the split harness ok?

Sorry to crash your thread Drtumolo, but I thought it was along the same lines.

My son is not shooting the scores he did with the old string setup. I know I have probably got the cams slightly out of sinc.


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## Drtumolo (Jan 19, 2003)

Javi if you dont mind I have another quistion for you. I synced my cams and timed the drawstop the way we discussed last night. Everything is now within spec (ATA, brace hieght and draw weight) I am still experiencing a nock high tear. You mentioned about making a small adjustment to the one cable to help if I still had a nock high tear ( I think you said the control cable). Am I remembering correctly? Do I need to twist the cable or untwist the cable to reduce the nock high tear? Thanks!!!!!


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## JAVI (Jun 19, 2003)

Drtumolo said:


> Javi if you dont mind I have another quistion for you. I synced my cams and timed the drawstop the way we discussed last night. Everything is now within spec (ATA, brace hieght and draw weight) I am still experiencing a nock high tear. You mentioned about making a small adjustment to the one cable to help if I still had a nock high tear ( I think you said the control cable). Am I remembering correctly? Do I need to twist the cable or untwist the cable to reduce the nock high tear? Thanks!!!!!


If you have the arrow set level or no more than a 1/8" nock high you most likely need to untwist the control cable a turn at a time... if the tear gets worse... then twist it back a couple of twists...


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## Drtumolo (Jan 19, 2003)

thanks Javi I will go give that a try.


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## Drtumolo (Jan 19, 2003)

Javi, I think I found my problem with my bow. I removed my new winners choice cables and re installed the original cables and I got a perfect tear within 2 shots. I dont know why the winners choice cables wont work but atleast I can shoot again. Thanks for the help!!!!!!!!!!!


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