Tuning with Arrow Length

kwilson16 · 12-22-2009, 05:36 PM

Looking for some input. Would this work? What would be the disadvantages?

1. Set-up the bow up for mechnical centershot with an EZeye.
2. Set vertical tune with nock or rest height.
3. Cut and fletch a appropriately spined shaft (err towards stiff) about 2 inches longer than required.
3. Shoot the tuning method of choice (broadhead in my case) - knowing the shaft will most likely show weak dynamic spine initially.
3. Cut a 1/4" off the shaft and repeat step 3 until the tuning method shows optimal spine/tuned.

Keeping the arrow in line with the string makes more sense to me than moving the rest.

Thoughts?

warbirdlover · 12-22-2009, 06:28 PM

In theory it should work but alot depends on the arrow rest and shooting form (consistency). Also the fletching needs to clear everything. You could also change the spine by using heavier/lighter arrowheads.

Let us know.

kwilson16 · 12-22-2009, 06:54 PM

Concur on the fletching. All bets are off without vane clearance.

Also concur on the lighter/heavier heads.

Gotta get some uncut shafts first...

3Children · 12-23-2009, 04:06 AM

One of the reasons I like the micro adjust features on some rest. I have paper tuned and had a great center shot, a bullet hole. But shoot out to 40+ yds and the arrow did not hit center.(not me) What I know happens when you line things up, the cams are at "rest", then things change as soon as the cams roll. The lean in the cams can be so small that you cannot see it, but the arrow shows it, by not hitting center. I have placed an arrow on the bow while in the draw board and as I pulled the string back I watched it move from the poi. The point was not more than 1/32" but we all know what happens if you draw a 1 degree line-the further you draw it the more it will be further! Example is a pilot that flies off just 1 degree in 500 or more miles could be in another country, or state. I tune a lot of bows, and the drawboard happens to be one of the most used tools I have for setting up a bow correctly. Now all that being said when I find the cam lean at full draw, I then adjust the rest ever so little, that is why I like the micro adjust so much.

BGfisher · 12-23-2009, 05:23 AM

You can do as you suggest, but it takes forever and if you are using carbon shafts with inserts glued in you'd have to cut that 1/4" from the nock end, which would mean either tuning with a bare shaft or refletching every so often. It's just more work than it's worth.

It would be much easier to just adjust the draw weight of the bow; one of the reasons limb bolts are on a bow in the first place. Why go through such as hassle playing with arrows when a couple pounds either way on the bow will accomplish the same thing. Afterall, poundage is just a number.

brucelanthier · 12-23-2009, 06:04 AM

Quote:

Originally Posted by BGfisher

It would be much easier to just adjust the draw weight of the bow; one of the reasons limb bolts are on a bow in the first place. Why go through such as hassle playing with arrows when a couple pounds either way on the bow will accomplish the same thing. Afterall, poundage is just a number.

Exactly!! Make the arrow for the middle poundage - 45-55-65 - and then adjust the DW to fine tune. An easy, efficient and exacting way to tune.

kwilson16 · 12-23-2009, 07:57 AM

3 children - I believe the micro-adjust would still be viable and valuable. I would try to keep the adjustments very small (close to mechanical centershot).

BG/Bruce - I prefer to shoot at the top of my draw weight range - which is only 60 for me - so I hate to give up any more draw weight. I would not cut from the nock end. I would just remove the insert with a drill bit, cut from the insert end and re-glue.

brucelanthier · 12-24-2009, 05:30 AM

I killed a deer this year with a bow set at 54lbs DW. It would have been an easy pass through except the BH hit the far side front leg. It busted the leg bone into 5+ pieces. While I am not pushing you to lower DW (I shoot another bow at 70lbs) I just want to point out that there is no real need to be at 60lbs.

Nalgi · 12-26-2009, 07:15 PM

you bare shaft tune then cut and fletch

are you asking for directions on bare shaft tuning?

TFOX · 12-27-2009, 05:27 PM

I don't trust the laser.That is putting too much faith in the centershot being machined exactly square with the riser.I am a tool maker and I know what the odds are with that many mechanical parts.It is probably close but it doesn't take much to throw a laser off quite a bit when you extend it over the distance of an arrow.

I trust Archers Advantage to tell me the spine arrow I need out of most high end bows nowadays.

Your method would require much trial and error that imo,isn't needed.