# Procedure to put in specs a true dual cam bow!



## Black Mamba (Dec 5, 2008)

Please, can you tell me the right procedure to put a true dual cam bow in specs and to have cams synchronized?

Thank you!


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## 3children (Aug 10, 2008)

I do this but unless someone tells me different this is what I do: On my draw board I make sure the cams or rolling over exact. I use a lot of white out to mark the cams. If it is your bow you can go a little further by using the limb bolts and a five shot group, fine tune the cams by turning them in or out to get the best 5 shot group, take notes!! I turn the bolts only a 1/4 turn at a time, this will take a while, and I have done this to a few customers bows but I don't make money on it. (too much time) I do not do this unless the string is new. (too much stretch)


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## subconsciously (Aug 22, 2009)

draw board 
creep tune
walk back tune

Tune the bow to you. Your ATA or BH may be a little off when you finish, but dont worry about it. If your getting great arrow flight, the bow aims easy, and you get good groups - let it eat.


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## TMan51 (Jan 25, 2004)

Black Mamba said:


> Please, can you tell me the right procedure to put a true dual cam bow in specs and to have cams synchronized?
> 
> Thank you!


Dual cam bows are different than a hybrid cam, in that they are not slaved together, except through the string.

The string will affect DL, and because the grip is not usually dead center between the limbs, equal turns on both cables, will eventuatlly affect tiller/timing. Shortening the string reduces DL and ATA, and increases brace height. Letting turns out, the opposite.

The cams should be taken in evenly, unless you need to advance/****** rotation at the top or bottom cam. Taking in cable on the cams increases DL and BH, and reduces ATA.

Start by turning your limbs all the way down, and backing each limb back out an equal number of turns. Check your specs, and write them down.

Draw boards are a great way to go, but they take up a bit of space. I use a 3/8" hook, mounted in a very solid overhead beam to check cam location at full draw. Most dual cam/wheel setups do not have marks, so you need to make your own, or eyeball the stop position carefully. Place the nock or loop on/in the nock/loop, and grasping the riser with both hands, pull the bow down, and check to see if one cam is rotated more/less than the other.

When the cams are turning over evenly, and ATA/BH/DL are correct, bring the bow to the desired weight, and start to tune with the nocking point holding the arrow square to the shaft, or slightly above square. Be prepared to adapt cam rotation slightly to tune the bow to you if you have a chronic nock hi/lo condition. (Also keep track of tiller as a reference). If you're not sure which way to go, put a half turn in one cable, take a half turn outa' the other. If it get's better, you can add/remove a half turn at either cable without killing the effort, if it's worse, go the other way on the turns.

I've used this approach on several generations of wheels and cams, and it works quite well. Do yourself a favor. Write everything down as you go. Soon you will see how much each change affects each of the dimensions, and you won't get lost, and frustrated. Don't be afraid to let a few turns out of the rigging to get started.

Good luck,


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## BTM (Dec 31, 2002)

I can usually feel them bottom out. If I feel a "bump-bump" when I hit full draw, then I twist the appropriate buss until the cams are synced (i.e., a single, solid "bump").

That being said, the above gentlemen gave good advice on how to proceed from there.


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## fletched (May 10, 2006)

Black Mamba said:


> Please, can you tell me the right procedure to put a true dual cam bow in specs and to have cams synchronized?
> 
> Thank you!


1. To get the bow in spec, you need to know the axle to axle and the brace height. To shorten the axle to axle, you can shorten the cables or/and lengthen the string. This will increase brace height and poundage.
2, To lengthen you axle to axle, lengthen the cables or/and shorten the string. This will decrease brace height and poundage. 

If the draw length is too long then do #2
If the draw length is too short then do #1
(this is assuming that the draw length is within 1/2", if the draw length needs to be longer than that, you may need to get a different draw module.)

To sync (time) the bow, it needs to be at full draw. You will need a nocking point established to time from. The cables on both cams need to drop into the draw cam track at the same time. Some cams are easier to time than others. It depends on how the draw cam track is designed. (the draw cam is the smaller track that the cable feeds into.)

Get the axle to axle close
Get the brace height close
Get the cams timed
Get the draw length right
Get the poundage right

Make sure the string and cable lengths are correct and haven't stretched to insure proper cam position, draw length and poundage.


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## Black Mamba (Dec 5, 2008)

*Apa black mamba mx1*

Hi guys, thank you very much!
I checked cams timing with a drawboard and cams seem to touch cables at the same tima at full draw. I have a solid wall at full draw.
Bolts are all in (limbs 50-60), I measured 60# but DL is too long (ATA is in specs). Mods are for 26" but I measured an AMO DL of 26.75". I wanted to put twist in the strings to short DL but it looks already overtwisted.
BH is 6" instead 6" 1/8!
I sent an email to APA to be sure how they measure DL in their bows but I didn't have reply. Rest hole is before pivot point about (1/2" - 3/4"). If they measure DL using rest hole as a reference instead of pivot point this means DL is almost right.
Have you experience with APA bows?
Thank you!


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