Another Broadhead Tuning Question

[El Gavilan]

Looks like you need to start over, set the center shot to recommended spec for that bow then yoke tune the top idler wheel to get a bare shaft to fly straight and hit with the fletched shafts at 20 yards and you will be good to go. With your broadheads hitting to the right, put a twist in the left yoke and take a twist out of the right yoke and give it a try, then add or subtract twists from there.

Mike

 

[TJ]

If it were me, I'd do the walk back tuning with BH's to start with. And then see where your FP's lie.

What kind of fletching are you using? Is it enough to overcome the planing of the blades? I'm not familiar with the Switchback, does it have a yoke? If so, you can yoke tune the impact difference out.

I have a Switchback XT. If your center shot is correct and your BH impact to the right of FP, like 5milesBack says, it may be you need to adjust your yoke.

Increase number of twists on your left yoke and untwist right yoke to match.

If you have access to a draw board you can check it yourself. At full draw your idler should be parallel to your string.

 

[TJ]

Looks like El Gavilan posted before I was finished. I do the same as he suggested.

Good luck

 

[jmez]

If you haven't yoke tuned a full twist goes a long ways. 1/2 a twist in one side and half out of the other will move your broadhead 4-5 inches at 60 yards.

 

[CAhunter]

I was able to do a little more tuning last night. In the end I had broad heads hitting about 3" left at 50 yards. Both were shooting well, I just never could quite bring them together. Because I was limited on time I cheated and adjusted my sights for the broad heads and called it good. I'm at work for the next three days and then take off on Sunday for a couple day backpack trip in the sierras. If I miss a shot it won't be the bows fault. After archery season I agree, I will have to start over from the beginning. Thank you for all the suggestions.

 

[Chris Sloan]

I was suprised not to spine mentioned earlier. Arrow spine is CRITICAL. I had the same issue w fixed blades and field points never matching. I picked out my arrows this year w help from the computer program at the pro shop. My new 300 VAP Sports came in last weekend and WOW! First test, i put a fixed blade, mech w prac blades and field point in the 'eye, shafts touching @ 25 yds. Acually shot the fix blade last and it chopped a fletching off on each of the other 2 arrows. Without the proper spine youll never get fixed blades tuned.

 

[Vizsla2]

I'd have to concur with Chris.
I followed the "old" arrow spine charts, which don't seem to be accurate for today's speed bows.

For me, I found that I was under spined (shooting a Bowtech Destroyer). Initially, my fixed blade broadheads always shot to the right of my field points. After getting stiffer arrows 400->340, my shots (Field Points and Broadheads) were right on. I wish I knew this earlier as it would have saved some time and frustration.
I played around a lot with cam lean and yoke tuning, but it never seemed to work. All along, my problems was under spined arrows.

 

[5MilesBack]

I was suprised not to spine mentioned earlier. Arrow spine is CRITICAL.

Spine was discussed earlier in the thread. He's shooting 340's out of a Switchback which are fine spine wise.

 

[Chris Sloan]

I was bein lazy and missed that. Im guessing if thats around a 330 fps factory bow turned up to 70, he could be on the weak side. Im pullin 70 with 300s but theres 175 gr up front. But fixed blades dont like 300fps + usually. That could also be a problem. Adding more weight up front and going to a stiffer spine is where its at .