Finch

Good morning guys!

The other day I decided to retune my bow since I had new limbs and cams installed. I maxed out my limb bolts and then backed them both off at one turn each. Theoretically my bow should be at even tiller. Correct? No need to measure. What about being timed?

Anyway, I've heard that some prefer their top cam to be ahead of the bottom cam. Does that mean that I don't back off the top limb bolt as much as the bottom (in my case)so the top limb is actually at a greater poundage than the bottom one?

Thanks

Redneck Bowhunter

Yes the tiller should be the same, but it wouldn't hurt to check. The Limb bolts do not affect cam timing. To check to see if they kick over in the same time (starting the valey) then hold the bow as horizontally as you can and draw your bow. Look at your cams while you draw. I use this method because I usually am by myself when tuning. But you can also draw you bow normally and have someone else check it out for you. Im not sure about having the top cam before the bottom cam. I have never heard of this. Most people want tiller to be the same but it is not as important as other things when tuning.

Finch

Thanks for the info. I really need to get another person to check my timing while I draw, perhaps.

I have heard of some people wanting their top cam to be "ahead" of their bottom one. Just wondering if that would mean tightening one limb bolt more than the other?

DaveC

Fairly certain that would be achieved through cable twist and not limb bolt adjustment.

I set mine up where both cable stops hit as the draw stop hit. Then I read a day or two later the cable stops should set to allow a sheet of paper to be pulled through at full draw (between the cable & the stop). I don't think I'm there- I bet mine would be tight.
As it stands both timing dots are cutting the second dot just a smidgen. I bet both are showing about7/8's of the circle. I'm not too concerned with this since back in 2006 the crackerized Tribute's were only coming back with 1 full dot showing instead of the factory suggested 2.
I know the dots are a rough estimate, but both of mine wound up the same when I was trying to "cable stop tune" or at least trying to do what I thought was so[8D].

DaveC

On second thought- I set my draw stop a smidgen over factory specs when iset it up last year. WhenI scaled it the other day I was sitting at 81-82% letoff. If I move the stop back to facotry I bet the cable stops would have the desired space and I'd go down to 80%.

BTW, from where ever I read it- cable stops touching before the draw stop would be hard to tune on a binary. Might have been here or on AT.

Finch

Dave,

I had no idea what I was talking about before.

I just joined AT and did a search and found some interesting threads about timing cams. Once I get home tonight; I'll get the GF to check where my cables are in relation to the cable stops, at full draw.

You have any experiences with Gritty's press?

I'm about to get in the tuning aspect of archery I never thought I would.

TradTech

Checking the time of your cams is very easy doing it yourself. I looked at the drawboards etc. I usually relied on my wife or son to watch the cams roll until I was just a smidge away from the flats bottoming against the cables.

What I have done to check the timing now is so simple, I don't know why I didn't think of it before.

I put and eyebolt into a rafter across my garage ceiling. Then tied a 3/8" twisted rope to it and knotted the bottom end. Before knotting the end, I slipped a heavy bungie cord hook over the rope and tied two knots to keep it from slipping off. You need to use the bungie hooks that have the sprial end to them.

The rope is just long enough so when I pull the bow to full draw with the bungie hook through the loop, the cams are about eye level.

Once the bow is at full draw, I make sure that I'm holding the bow with two fingers inside the throat of the handle. Don't hold the bow by riser in two locations. This will not be accurate.

I back off just a little and watch as I slowly bring the flats of the cam to the cables. Looking at the bottom cam as I do this. When it just barely touches I'll look at the top cam. That will tell me if the top cam is over or under rotated.

I'll then twist/untwist the appropriate cable to make the adjustment so both cams bottom out at the same time.

Here's a link for hybrid cam1/2's that may be useful.


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

Straightarrow

Not neccessarily so. I've had several bows where the tiller was not even with bow bolts all the way in. In fact. It's very easy to measure but not super critical. If you tiller tune (using Arthur's method), you'll seldom end up with even tiller.

Arthur P

Well, you really can't wind up with even tiller if you actually think about it a bit. On most bows the grip is below center on the riser. The old lever and fulcrum thing. The riser is the lever and your hand is the fulcrum. If the grip is on the exact centerline of the riser, then you'll wind up with even tiller. If it's not, you won't have even tiller.

If you want the lever to balance, the longer end of the lever takes less force than the short end. Most current bows are made with the arrow pass set at the vertical center of the riser, with the grip about 2" below that. So the fulcrum on our bows is closer to the bottom limb. To make the load balance around the fulcrum, draw weight has to be set slightly higher on the bottom limb. The bottom limb usually winds up measuring 1/8 - 1/4" closer than the top limb.

Some people - unfortunately the ones who get repeated the most - think since the arrow pass is close to the center of the bow, the tiller should be set even, to balance the load over the arrow. Sounds good doesn't it? BUT, the arrow pass is above the fulcrum. When the limbs start moving back to brace they are not returning with the same timing or the same force.

Draw the bow slowly with the tiller set even and watch what it does. Keep in mind that the bow is going to react the same way when you turn the string loose. I can almost guarantee that, with an even tiller, the bow will rock backward in your hand making your pin insist on pulling up off the target. It will continue to insist on that while you are trying to aim. It will still insist on doing that when you release the string.

No big deal, really. The bow can be tuned to shoot accurately either way. BUT...

With tiller balanced over the grip, the bow will hold steadier in your hand as you aim, which will make that pin not move around as much. The limbs will return to brace at the same time (we're timing the limbs, if that helps you visualize it better) so the bow will be quieter with less shock and vibration.

Not to mention the bow will be easier to tune when the limbs are working together to keep the riser from rocking back and forth over the fulcrum during the shot.

GMMAT posted on the bowhunting forum a link to a video that shows what I'm talking about. It's perfect!

http://youtube.com/watch?v=fwTizMtvKwI&mode=related&search