4th Axis Tips
This page will keep you informed of the latest techniques used to tune the 4th Axis.
Note:
It has been brought to my attention that there are sight extensions out there that are not straight. In fact they are slightly twisted. This can create some headaches when doing the "In-Out" test. Because of that and if you are not sure, I would go to the next paragraph and follow those suggestions.
Here's the latest:
I have discovered a quick method to check the 4th Axis to arrow path relationship. Very simple and you do not need to do the "In-Out" test. I will continue to refine the setup of the 4th axis and recently a question was raised about setting it up on a sight without a 3rd axis adjustment. Kill two birds! I will assume that most sights that do not have a 3rd axis adjustment are machined square and so the 3rd axis is probably close to perfect. If you attach this sight to a Tek-Tech 4th Axis you now can adjust the 3rd and 4th axis to the arrow path by shooting the bow. Here is how you do that: Set your windage at 20 yards on a flat range. Then find a steep up or down hill target. I prefer 80 yards down hill as I can aim better down hill. ;o) Shoot a group. If that group is not dead center you need to adjust the 4th axis. When aiming down hill you need to move the front of your sight a very small amount away from the center of your group and towards center of the target. Re-set your windage and do it again. First the flat 20 then the steep downhill. You can also shim the sight mount to accomplish this but it takes a lot longer. I actually am using this technique on my slider sight now and it works well. I think it may make more sense to folks than the “In-Out” test I have mentioned elsewhere.
Due to the fact that this concept is very new there are bound to be new ideas and suggestions. I will attempt to post as many different techniques from the users as possible. If they shooter wants me to list there name I will also do that. This will be limited to what they did to tune in the 4th Axis.
Anyone wishing to share that information can e-mail me at:
I will start off by sharing my personal experiences and then expand as folks respond.
Your first priorities must be these:
#1. Set your 2nd and 3rd axes without taking any torque into consideration. In other words, off the bow or on the bow at brace height in a bow vice.
#2. Be absolutely sure that your arrow rest is set to the optimum center-shot position for the arrow you are going to use.
A method to do that is as follows: The "Walk-up" test! Shoot at a perfectly vertical line at 15 yards. Adjust your windage to hit the line. Then step forward 3 yards and shoot at the line again. Then step forward 3 yards and shoot at the line again. repeat this process until you have shot an arrow at 3 yards at the line. That will be 1 each at 15, 12, 9, 6 and 3 yards. DO NOT MOVE YOUR WINDAGE DURING THIS TEST! If your arrows all hit the line you are ready to do the "In-Out" test. If not, move you arrow rest 1/16" in the direction of the miss and do the "Walk-up" test again. If your misses are larger you moved the wrong way! Move the other way and do the "Walk-up" test until you hit the line with all 5 arrows. Now you can proceed to the "In-Out" test.
To begin, as the the instructions indicate you should start at a close distance of about 10 yards to do the "In-Out" test. (This is described on the 4th Axis Instructions page) I have found that this is not the final step. This will get you close! Once you have set the 4th Axis at 10 yards you will need to move farther out. Lets say 20 yards for starters. If you are right in the center of the dot you need to check it at 40 yards or farther. Eventually you may want to check it all the way to 80 or 100 yards. All of these checks will be at your normal sight extension. The reasoning behind this is simple. At 10 yards or even 20, a small error is hard to see and therefore will increase as the yardage gets longer. When you move to 40 yards or 50 the error will show up and you can tune it out. Lets go back to 20 yards and deal with an error. Lets say that you shot to the right about an inch. Make a small adjustment on the 4th axis toward the miss. (possibly 1/8th of a turn on the set screws. Counter clockwise on the flathead and clockwise on the set screw.) Remember that this an adjustment and you only need to snug these screws up firmly. Do not tighten them real hard! Then adjust the windage to center and do the "In-Out" test again. Remember that the farther away you get and do the "In-Out" test the farther apart your arrows may be. At some point in this set-up you will need to move your sight during the "In-Out" test. At 40 yards I have to set my sight on 35 for the in and 50 for the out. I would venture to say that the farther away you are able to do the "In-Out" test the better the end results will be.
With that said, I will allow the users to give me input to post on this page. I am sure that some of you will have improvements on this process.
Shoot well!
Gene