A First-timer's Bow Setup and Tuning Thread

[Brewskis]

While I had the bow drawn back on the draw board, I checked the cam timing. Interestingly, the bottom cam is now ahead of the top cam.

Bottom cam (draw stop just barely touching cable):

Top cam:

Now in full disclosure, I shot the bow perhaps a handful of times last night (more on that shortly). Would that little bit of shooting already have stretched the cables enough to cause this?

 

[Brewskis]

As I just mentioned, I fired the first shots last night. Just couldn't help myself. I shot a bareshaft at about 5 feet through paper a handful of times. I know I'm not done, so I had no idea what to expect. In the back of my head I thought I'd be getting all kinds of ridiculous tears. For what it's worth, here's the results.

Suppose the good news is that I consistently got the same tear (to varying degrees) with each shot. A slightly high left tear.

This evening, I again shot another handful of shots with a bareshaft at 5 feet through paper after taking the bow off the draw board. Similar results with one perfect bullet-hole thrown in to tease me.

So, at this point I believe I'm suppose to look at cam lean, right?

 

[Kris87]

Put two twists in the left yoke and leave the right alone. If u still get a high tear, take a half turn out of top limb bolt. See what that does.

 

[Kris87]

Jeremy, sorry, do one full twist in that left yoke.

 

[Brewskis]

OK, I added one twist to the left yoke. I decided to quickly check the cam sync using the ceiling hook, and both are now hitting at the same time.

I then shot three bareshafts (numbers 1, 2, and 3 below). The first one had a tiny bit of nock right. Could have very well been me (e.g. my grip). Shots 2 and 3 were perfect bullet-holes. I thought, 'sweet!'

I was hanging up the bow, however, and noticed that the launcher arm of the rest was partially raised. Apparently, I had not tightened down the cord screw enough, and it had slipped a bit. I decided to lower the arm completely, re-tighten the screw, and try shooting again.

I shot numbers 4, 5, and 6 below, and as you can see, each of them was nock low...

Any idea why correcting that issue with the launcher arm would have done this (assuming that was the cause)?

 

[Brewskis]

*added one full twist

 

[C Cape]

Awesome thread! You're doing a great job so far! I've seen work from shops not as well done.

Normally the timing will be slightly different going from pulling the bow on a hook and drawing it on a drawboard. I would take that twist back out of the control cable and you should be pretty close.

 

[Brewskis]

Thanks, man! Appreciate the kind words, and the suggestion. I won't be able to get back to it until late tonight.

I was thinking about putting it back on the draw board tonight, and checking the cam sync again. I read somewhere how differences in the way the bow is held can affect sync readings.

What's got me confused are the bullet holes I was shooting before I noticed the launcher arm was partially up. Unfortunately, I'm not sure how long the arm was in that partially-raised position, but I feel like I would have noticed it before beginning to draw back. Therefore, I'm kinda thinking it slipped after shot number 3.

Would difference in cord tension after pulling down the launcher arm, and re-tightening it down have affected arrow flight that much? I thought I tied it down the same way it was before, but I could have unknowingly done it differently...

 

[Brewskis]

Still thinking about this, and came up with a couple other questions.

How tight is too tight for the cord? (I know it's important not to make it too tight, but it seems this Pro V required more tension in order to hold the arm all the way down than the Pro V on my other bow. In other words, the required tension to hold the arm down on the new Pro V seemed much more (closer to a guitar string) than my other one that been used for some time).

Any tips on how to make sure the screw holding the cord is tightened down just enough so the cord doesn't slip again, but isn't overtightened? (I read it's important to not torque it down, but just snug it up)

 

[Kris87]

Its entirely possible for just the first few shots for the buss cable to stretch enough to get the sync back off. You're going to need to check it again in a couple hundred shots. I try not to use the cam sync too much to control vertical tears. I primarily try to set it so that I like the way it feels, which normally is the top just barely ahead of the bottom. That makes it feel firmer. If you go too far one way with either cam, then it can start to feel mushy, and it'll feel like it has more creep. So try to set it right, then use the nock point, or the rest height, to control the vertical tears.

Do like Cape said, and take that twist back out of the control cable. If that doesn't make the sync where you want it, and it doesn't clean up that nock low flight, then go to the rest. You can always turn the top limb bolt a 1/4 turn and see if that will fix it too. Its not bad where it is obviously, but its easy to fix it too.

On the Pro-V...your cord will stretch initially. I typically tie mine on, then use my finger and just put a lot of tension on it until I feel like its not really going to stretch any more. Then retighten it. I like to tighten it so the arm is all the way down against the rubber, then again, I just push on it until the arm is slightly raised off the rubber pad. I leave it there.

 

[Brewskis]

Alright guys. I took the one full twist out of the control cable (at the top again).

I put the bow back on the draw board to check the cam sync. As expected, the bottom cam was now behind the top again.

Here's a pic of the bottom draw stop when the top draw stop is barely touching the cable (gap shown is right at 1/8")

I then decided to apply the suggestions Kris gave regarding the rest cord before moving on to shooting it since I didn't want to deal with any issues again like yesterday.

I put a lot of tension on the cord to help stretch it. Then re-tightened it.

I then took a couple shots... I was now getting even worse low tears... As I was about to take a third shot, I discovered what the cause was. The rest slid completely up. The elevation adjustment screw had been slowly working it's way loose, and had finally loosened enough to allow it to raise up to the upper limit.

After checking the level of the rest, the level of the arrow in relationship to the nocking point, and making sure all fasteners were securely fastened, I fired four more shots.

All four were left slightly high tears.

Did the rest changes I had to make perhaps reset all the other changes made? Last time I was getting that tear, I put one full twist in the left yoke. Same move here, or should I do something else?

 

[Kris87]

How much is the cam leaning now when you lay the arrow flush on the left side of it? Where does the shaft cross the string. I had a bow last year that when I made changes to the cam sync, it also gave it a left tear. Never had seen that, and it didn't really make any sense to me. But besides that, how much lean have you induced up to this point? Check your centershot one more time too.

 

[Brewskis]

That's actually something I was going to ask you about. I noticed that the top draw stop at full draw was to the left of the cable. In other words, the stop wasn't centered on the cable when it touched it like I would have expected. It almost looked like it would completely miss the cable and pass by it if it was just a hair more over to the left.

Out of curiosity, after I took the bow of the draw board, I did what you just mentioned, and placed an arrow flush along the left side of the top cam with the bow at brace. It never crossed/intersected the string. It just ran parallel to the left side of the string.

I can't remember for sure if I did this again last night after taking that one full twist out of the control cable. However, I know I did this after putting the one full twist into the control cable (and possibly after the one full twist into the left yoke).

Either way, I'll check that and the center shot again this evening.

 

[Kris87]

If your shaft isn't intersecting the string at all, then you just need to dial in some prelean. That will clean up that nock left travel. Its also a reason your top stop is sitting on the left side of the cable. When your cam is straight at brace, it rotates this way during the draw cycle /(looking at it from behind). So by leaning the cam just a little this way \ at brace, it will move to this position | at full draw.

Hopefully that makes sense. If you want to understand why the cam moves. I'll explain that more. But for now, just dial in some twists in the left yoke, and out of the right, and it'll head in the right direction.

 

[Brewskis]

Yeah, that makes a lot of sense. So is there a specific place I should look to get the arrow to intersect the string in order to know I have a enough prelean?

If when I check it tonight, the arrow is in fact running parallel to the string, and not intersecting it, what would be your starting recommended number of twists to add to the left and remove from the right (bearing in mind that I already put one full twist into the left)?

 

[Kris87]

There's no right answer. Just dial it in until that left tear is gone. Yours isn't going to require much, which is a good thing.

 

[Brewskis]

Decided to go for it, take it slow, and see what I could figure out.

I first put an arrow flush against the left side of the top cam. Sure enough the arrow was not even starting to intersect the string until near the string stop.

I rationalized in my head that if I had already added one full twist in the left yoke (post 45 for those keeping score at home), that my first move should be removing one full twist from the right. So I did that, and then checked the cam sync. The top cam was now ahead by only 1/16". Perfect! However, when I shot it through paper, I got a similar tear as before except to the right. OK, no problem. Maybe I should have just tried removing a half twist instead of a full one. I added back a half twist to the right yoke. Checked the cam sync again, and the top cam was back to being ahead by about an 1/8". However, that seemed to have gotten rid of the left and right tears. All that was left was a tiny bit of high tear.

The shots above were all at 5 feet. I decided to try a couple at 10 feet. As you can see, the shots at 10 feet seemed to amplify the high tear.

Would a rest/nock change get rid of that, or even just a turn of one of the limb bolts?

 

[Brewskis]

There's no right answer. Just dial it in until that left tear is gone. Yours isn't going to require much, which is a good thing.

Our posts must have crossed paths. You're right, it didn't take much (just a half twist removed from the right yoke) to get rid of the left tear.

 

[Brewskis]

Forgot to mention I checked the center shot measurement, and it is still at 3/4".

Also, here's a photo showing the present cam prelean after removing the half twist from the right yoke. Arrow now intersects the string around the D-loop.

 

[Kris87]

Good job. I wouldn't mess with the yokes or cables much now. Your back wall should be pretty firm, you don't have a lot of cam lean, and that's a good tear. From here, raise the rest a skosh or take a quarter turn OUT of the top limb bolt. U basically need the loop to move down a hair or the rest up a hair. Pick your poison.