[C&P] My Compound bow tuning process;
I always start by checking timing marks and exact axle to axle measurements as first steps.
Note- if you skip steps, it can result in frustration
1. Set the bow to factory specs; cam timing, axle to axle, rest
Cams- most have timing marks now. If not, check on a draw board at full draw then scribe the cam when they roll over perfectly timed- (no skipping this step)
Confirm Axle to axle measurement- factory distance is a perfect cable and string setup
Rest- its usually 13/16” in the new compounds but its designed to shoot at factory distance. Dropaway rests need to be timed to come up late
2. arrow; Make sure your arrows arent underspined. A over spine arrow tunes well in a modern compound and gives you a more durable arrow. I’ve had the 8gpi and under shafts not hold up well. Look at 9 or 10 gpi min for a hunt arrow shaft.
Spin check arrows for perfect straightness and nok tightness. A tiny wobble and your BHs won’t group.
3. Set string loop with a tiny spacer ( wraps of floss or thread on the inside of the loop, one side is fine) so the loop isnt tight on the nok. The strategy here is not to have the loop itself applying up/down pressure on the arrow nok. Nok pinch is bad.
At this point you have multiple options for arrow tune; shooting a bareshaft with FPs, shoot paper, or just shoot BHs and FPs. Follow the charts in the OP.
Worth noting;
Paper tune with FPs is only 1/2 tuned
If your BHs dont hit with FPs, the BH arrow is telling you your arrows are coming out of the bow cockeyed. When the BH arrow hits with FPs, thats when your arrows are truly coming out of the bow perfectly straight.
When BHs aren’t perfect:
1. If the above steps are done and BHs still don’t hit with FPs its worth experimenting with your form and grip before you start moving stuff. Sometimes its just a minor grip change. Check form alignment.
2. check for fletch contact with powder.
3. Bow Adjustments; It usually takes tiny movements to get it right. That can either be accomplished by adjusting yokes, shimming cams, twisting the Yokes or tiny 1/32” rest moves. If you move your rest more than about 3/16” from factory recommended setting, something else is wrong…it doesnt take that much.
Rest adjustments are tricky. when I BH tune; shoot BHs and FPs for groups- I typically chase the FP group ( move rest toward the FP group) in 1/32” incriments. This usually works…but if not….(and you have checked all of the other factors above) I have had it where a paper tuned for FP was past the perfect setting- over shoot the adjustment- and to keep chasing FPs with my rest made it worse, go back the opposite direction a tiny bit.
Key Point is; its never much past factory recommended setting for your rest.
I probably forgot something…but thats essentially my process. If you skip a step….or have a form flaw especially alignment…or are shooting arrows that don’t spin perfect….you will not get that bow to tune.
I hope that helps….Best wishes to my bowhunting brothers….
It sounds like a lot ^ but its one of those things thats worth getting your arms around, understanding the factors in perfect arrow flight. Your bow will be quieter, faster, smoother…and more forgiving of a form error in the woods.
.
