# Timing an Apex 7 cam



## tjwood (Oct 30, 2006)

Hi,
I've just bought an Apex 7 off AT but I think the cam is slightly out of tune. The timing 'dimple' is sitting just under the edge of the limb. I think it's supposed to be just clear of the inside the edge of the limb. The ATA is spot on but the draw length is about half inch short. The thing is I'm not sure if this means the cam is under-rotated or over-rotated AND I'm not sure how I can fix it. Does the cable/string need twisting/untwisting?

Any help gratefully accepted.

Thanks
Tony


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## andy7yo (Nov 22, 2005)

http://forums.mathewsinc.com/viewtopic.php?t=40837

Both holes should be parallel to the string. Never seen a Mathews cam run short either, you sure about the measurement.


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## Super Tuner (Dec 24, 2008)

I'm guessing ur poundage is on the low side of what its supposed to be maxed out, make sure your limb bolts are all the way in tight, if they already are give your cable a twist or two like if you were shortening the cable, the best way to check your cam alighnment is with a staight edge, lay the straight edge on top of the cam lined up with the holes or dimples on the cam, then measure down from the string to the straight edge, take two measurements, one near the cam and one near the idler, they both should be the same, after you get them the same check your axle to axle, it should be good, i have set up alot of these bows and they set up easy and tune easy also.


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## Purka (Sep 8, 2004)

The cable needs to be twisted up some which will increase your draw length and poundage and will also rotate the cam back.


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## tjwood (Oct 30, 2006)

Hi guys,
Thanks for your replies.

After 15 hours of trying I'm still no nearer to getting this Apex 7 properly set up.
I don't know why I'm having such problems - I can set up a cam+half bow in under half an hour but this Solocam has me beat.

After more fiddling today I now have a bow thas has:

A draw length half inch longer than spec (27" instead of 26.5")
Peak weight 3 pounds less than spec (57 instead of 60).
ATA 1/16" shorter than spec.
Brace height 3/16" higher than spec.
Cam Timing 'dimples' pointing slightly towards the riser.

All measurements taken with limb bolts fully tightened.

I checked the string length and it's 3/16" short of its 95 inch spec but I'm sure such a small amount would cause me all these problems would it?

Also, when I back out the limb bolts to reduce the poundage to my shooting weight of 53 pounds, the draw length increases slightly (about 1/4") - is that common on Solocams?

I've read that shortening the string will shorten the draw length - what do you reckon? I it's true I'm going to have to put in a lot of twists to get rid of half inch of unwnated draw length. I'm also concerend what other problems this will introduce.


I'm really struggling now - any more help or advice gratefully accepted. 

Regards,
Tony


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## dwagoner (Sep 27, 2007)

if the holes to align cam timing are pointing towards riser then you would need to shorten buss to rotate the cam, this would move them more inline with string. i would work to get bow into spec and then see where your at. sounds like just a little more tweaking. if your ATA stays withing 1/16th after you get cam timing spot on then i wouldnt worry about that but remember to measure both sides to compensate if there is idler lean while at rest.


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## Super Tuner (Dec 24, 2008)

Have u checked the cam to see what draw length its supposed to be and how r u measuring the draw length?


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## Super Tuner (Dec 24, 2008)

If ur measurements r what u say they r it sounds like to me ur string is too short and u need to take a few twists out, start with taking 2 twists out on both ends of the string and remeasure, just make sure u take ur measurements with the limb bolts bottomed out, remember this, when u shorten the cable it increases poudage and lengthens ur draw length, when u make the string shorter it decreases poundage and makes ur draw length shorter.


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## tjwood (Oct 30, 2006)

*I think it's there !!*

Hi guys,
Thanks for all your help.
After yet more tweaking I've finally sorted it - the string is 95 inches when untwisted. When it's got the correct number of twists in it it's way too short. I'm hoping someone here will confirm that the string length printed on the limb is for a twisted up length.

I now have the bow totally in spec but there are almost no twists in the string so I'll need to get a new one made to the correct length.

Even with the current string it's still shooting bullet holes so I can't wait to get it down to the range to see what it's like at a reasonable distance.

Thanks again.
Regards,
Tony


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## dwagoner (Sep 27, 2007)

check this for your string lengths

http://forums.mathewsinc.com/viewtopic.php?t=40940

and FYI for cam timing if needed, or save these
http://forums.mathewsinc.com/viewtopic.php?t=40837


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## Super Tuner (Dec 24, 2008)

Hi Tony, ur string length should be 95 1/4 and im not sure how ur measuring ur string but its is measured under load, in other words its got to have tension on it as u measure it, the same tension as if it was on ur bow, i checked the tune charts that i have and for an Apex 7 string length is 95 1/4, cable 40 1/2, ata 38 and brace height 7"


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