Fine tuning problem

[sidnren]

Picture 1- I had to move my whisker bicuit rest all the way left to get it papered correctly.

Picture2- King of Spades is target at 15 yards. My sights are all the way left. No more adjustment.

Martin Rack Master from Dick's.
I noticed the M-pro cam is spaced all the way left and the string on the idler is riding on the left side.

If I move the biscuit right to compensate, I get a vibration and noise and lose accuracy ( paper right)

Is this right?

[bfisher]

I'd like to see more info on the setup. Draw length of bow and draw weight. Arrow spine and length, tip weight and fletching type.

Most of my Martin bows have the rest set just about 15/16" from the sight window and my arrows are on the stiff side. I don't paper tune, but do bare shaft tune. What I'm hinting at is that your arrows might be stiff and need the rest set to the left to compensate.

One thing you might have happening is idler wheel lean. Have you addressed this yet? Usually with a RH hand bow the limbs are twisted with the top of the idler wheel tilted to the left. If yours is like this then you need to add some twists to the right hand side of the cables yoke where it attaches to the top limb. Holding an arrow along side of the idler and parralel with the string is a good way to check it. How many twists you might need is a matter of trial and error. I've had some bows that require 5 twists and some as many as 16 twists.

This is pretty common to single cam bows so don't think it's a Martin problem. Just one more reason I have gravitated away from single cam bow and back to dual cam systems.

This may not be a problem with your bow, but it is one thing that should be checked and corrected during any initial setup.

[sidnren]

First, Thanks so much for getting back so quickly.

Martin Rack Master
purchased Oct. 2008
67 lbs draw weight
29" draw length
Beman ICS Hunter 340, 9.3gpi
Arrow length from tip to knock 29"
100 grain points
Tru-Glo extreme front sight
Whisker Biscuit rest
Hind sight rear sight

When i first got the bow it had alot of vibration and I had to take it back 3 days later because the front site just fell apart and broke the pins.
The salesman at dick's said that the sights provided by Martin were junk. I told him it was a set up issue. He told me I was torquing the bow because I has holding it to tight. I now rest the bow with an open hand.

I put on a STS about 2 weeks ago from Martin. I also installed the Hind Sight MX to ensure I wasn't torquing upon release. I still had lots of vibration and noise.

Vertically, The bow has always shot flat, horizontally it is all over the place. Best is 3" @ 30 yards. left or right of center.

I decided to papertune and saw that it was shooting Right tear. Called Dick's and they ensured me I am shooting the right arrow for the poundage. So I moved the rest left as per Martin Instructions. Vibration and noise all but gone. Shoots faster and smoother.

I just cant get any more adjustment.

Again I appreciate any help I can Get.

[sidnren]

Sorry I forgot. Center of rest to edge of sight window is 1 1/4".

Notice there is no more adjustment left.

[bfisher]

There is some idler wheel lean so I would address this first and foremost. Right tears are often a symptom of idler lean. Then try again through paper.

It is possible your arrows are too stiff for the bow. A lot depends on your form, but I have a Moab with the same cam system that requires a much softer arrow than my FireCat, even set at the same draw and weight. I haven't worked that much with it, but that's what I've found. Not that Dick's was wrong. The 340's are what most people use, but with harder cammed bows

Couple things you could try after aligning the idler. Try a 125 gr tip or a 400spined arrow if you have one or can borrow one. Also, is it possible to turn the weight up on the bow? A couple pounds or a combination of this stuff might tell you more of what's going on.

Work with the rest a bit, too. You should be able to move it in to about 1" from the window. This should bring the sight over and give a lot of adjustment room.

Let's go from there and see what happens.

By the way, those are some good pictures.

[sidnren]

Thanks so much for your wisdom. I'll give it a try and let you know how I make out.

Again, Thanks so much.

[masterofthese]

I have had the same problem before, when it was a year before I picked up my bow. It took me a month to realize I was using my release wrong. Have an archery pro shop watch you at full draw, and make sure you are using proper back tension and not vertically or horizontally torquing your release. Since you are getting groups, the only other thing could be bowstring twist, or idler lean, or possibly cable guards over adjusted, from my experience. Hope this helps....

[bfisher]

Something else I just thought of that is often overlooked-----nock fit to the center serving. Too tight can cause problems. Nock should snap onto the serving but be just a tad loose when seated.

Nock an arrow and hold the bow horizontally so the arrow is hanging toward the floor. Give a sharp tap on the bow string. The arrow should drop off.

[OregonHunter]

Sidnren,
You should move your whisker biscuit right, not left. It should be moved to the right if you shoot left, inverse of the sight.

[eldermike]

Not sure but bfisher should know, should those cables cross above or below the cable guard?