Cam Timing Issue

[wnelson14]

Can some one please help, recently got into doing my own bow stuff, bought an Almost new V3X, immediately replaced the strings, I didn’t check the timing before hand which is in me I guess.

The cam picture that is touching the stop is the bottom cam

The one far away from touching is the top.

Which way do I twist the yoke cables or what is best solution? Thank you

 

[Jdoud033]

Add twists to the cable that connects to the cam hitting first.
Be aware of your ATA/BH/PW as your adding twist as well.

 

[BBob]

That one is way out! Can it possibly just be just a twist amount or is there a cable mismatch or something going on?

 

[wnelson14]

That one is way out! Can it possibly just be just a twist amount or is there a cable mismatch or something going on?
Everything looks good to me, I have an older vxr that I can sort of reference things to and I took pictures and did one string at a time when installing new strings, I didn’t measure any of the string lengths because I ordered them from ABB and selected everything correct and they had a QC sticker so I assumed they would t get that wrong,

I will also add the bow has 75# mods and is pulling only 70 lobs with limbs tightened all the way

 

[BBob]

Pull the buss cables and lay them (stretch and pull) side by side. Are they the same length?

 

[wnelson14]

Pull the buss cables and lay them (stretch and pull) side by side. Are they the same length?

I will check that out, thank you

 

[Mighty Mouse]

Press the bow, slip the end loop off the cable peg on the bottom cam, add a twist or two to that cable then put it back on the peg. Repeat until the cams are in time then check your draw weight. If you're still measuring light on draw weight with the cams in time, add twists (in equal amounts) to both cables until you hit draw weight spec.

 

[wnelson14]

Press the bow, slip the end loop off the cable peg on the bottom cam, add a twist or two to that cable then put it back on the peg. Repeat until the cams are in time then check your draw weight. If you're still measuring light on draw weight with the cams in time, add twists (in equal amounts) to both cables until you hit draw weight spec.
View attachment 499654

I got the cams perfect in time, draw weight is within a 1/2 pound but my ATA is long by a 3-16-1/4”, what would fix that or does that even matter.m?

 

[Billy Goat]

I got the cams perfect in time, draw weight is within a 1/2 pound but my ATA is long by a 3-16-1/4”, what would fix that or does that even matter.m?

Check the actual draw length if you can, Mathews will be 1/4-1/2" longer than the mod states, generally closer to the 1/2" long.

The ATA is a +- 1/4", so if it's supposed to be 29, it can be 28.75-29.25 and still be in spec.

How many twists did you need to put in the cable? The SW bows have a lot of the cable length served and it makes it a pain to twist/untwist. It can take a while for those twists to work their way out, and if you need to untwist it will frequently loosen serving.

Here's a chart to use in reference for what things change with adjustments.

 

[Mighty Mouse]

I got the cams perfect in time, draw weight is within a 1/2 pound but my ATA is long by a 3-16-1/4”, what would fix that or does that even matter.m?

±1/4" on ATA is close enough IMO. Trying to get everything exactly to spec will have you chasing your tail. You'll likely see a slight variation in ATA from one side of the bow to the other BTW, which is normal.

If you did want to shrink ATA, continue adding cable twists. Or you could add twists to the string (but that would also reduce DL and DW). Below is a handy reference chart that shows the directional effect of adding/subtracting twists.

 

[wnelson14]

Check the actual draw length if you can, Mathews will be 1/4-1/2" longer than the mod states, generally closer to the 1/2" long.

The ATA is a +- 1/4", so if it's supposed to be 29, it can be 28.75-29.25 and still be in spec.

How many twists did you need to put in the cable? The SW bows have a lot of the cable length served and it makes it a pain to twist/untwist. It can take a while for those twists to work their way out, and if you need to untwist it will frequently loosen serving.

Here's a chart to use in reference for what things change with adjustments.

View attachment 499868

Thank you! After adding and subtracting twists from the top and bottom and checking multiple times I couldn’t tell you the number of added and subtracted twists, I do know visually the bottom cable strands are twisted more. I’ll check DL after work, if it all checks out I’m not going to chase my tail to correct ATA. Thank you for the help

 

[Billy Goat]

Thank you! After adding and subtracting twists from the top and bottom and checking multiple times I couldn’t tell you the number of added and subtracted twists, I do know visually the bottom cable strands are twisted more. I’ll check DL after work, if it all checks out I’m not going to chase my tail to correct ATA. Thank you for the help

If you are visually seeing the difference, I suspect either one of the yokes or the cable was laid out incorrectly. It could be you have them in the cable guard incorrectly, but you said you referenced it against a VXR, I can recall if they have the same routing, but I assume they do, cable guard of course sits just a little closer to the bottom cam.


I don't measure stuff immediately, I usually put it on. However if I saw something as far off as what you had I would have measured, determined what was wrong.