Nock tuning conundrum
Equipment
I'm having issues with nock tuning on a new arrow build... I've only built one arrow and wanted to test before making more.
Ingredients: 4 fletch with arrow wrap, 30" 5mm Axis, 75 grn brass insert, 150 grn head, Nokturnal nock.
Shooting thru paper at 20 ft I will get a 1 inch left tear. Rotate nock 90 deg... I get a 1inch high tear. Rotate 90 deg... I get a 1 inch right tear. Rotate 90 deg and yep... 1 inch low tear.
Both shaft ends were squared. Swapped out head for a 100 grn head and same results but not as bad of paper tears. Bad nock? Bad arrow? Any help would be appreciated. Thanks
So basically, you’re saying that the shaft is doing the same thing - kicking out a bit - regardless of nock orientation?
Have you tried swapping out the nock?
I guess I would put the arrow on my spine tester and rotate it through 360° looking for a stiff side.
Bou- thats kinda what I was thinking but wanted to make sure I wasn't overlooking something.
Cora- Yep... as I turn the nock the tear rotates along with it as well.
Did you spin it to look for wobble? I'd start with new nock then maybe new insert. Something isn't straight
Did you post your bow, draw weight and length? That’s a lot of foc on a long arrow.
I did a spin test and it appears to be good...
The FOC for 150 grn was 14.9% FOC for 100grn is 11.4% So the foc isn't too high ot low...
Appreciate the questions
Axis shafts are known for radial spine variation. I stopped using them several years back for that reason. I'd typically have 2 or 3 shafts out of every dozen that were obvious flyers, after fletching. Sometimes I could index the bad shaft to create a work-around solution, but not always. Once fletched with say, 3 Blazer vanes.....for a lot of bow rests, you're then locked in to selecting either 120 degree or 240 degree of index. So you might get lucky by rotating the nock to one of those two positions, or if not then perhaps try re-fletching. With your 4-fletch set-up you should have a little more flexibility. I believe the aforementioned radial spine variation results from a flaw in the manufacturing of the Axis carbon fiber tubing.
Sticksender- appreciate the input. I'll keep that in mind. I've been using the CarbXpress almost exclusively for 12-15 and had bought these shafts last year when the pro shop was out of my regular shafts.
First thing I'd do is move to 6' for paper tuning and then I'd take a look at this. All carbon arrows I've ever seen have spine inconsistencies with the exception of the expensive ones.
https://eastonarchery.com/wp-content/uploads/2019/08/TuningGuideEaston.pdf
Tuning problems virtually disappear when you have something to reference other than opinions on social media.
FOC is too low… According to some guys it should be 96% foc. :)
All kidding aside 1 arrow isn’t a good enough sample. Some times you’ll just have a “bad” arrow maybe that’s the one
FDP... yep I shot at 5-6 feet also. Pretty much the same results just not as exaggerated. Also shot at 15 yds and it was much less noticeable. Which I'm assuming is when the vanes are starting to get to work.
Shug- I'm pushing 21% on my 1025 grain buff arrow... is that better lol!!
I agree to build another arrow and see if you get the same results. Back in my competitive shooting days, everyone used Easton ACC arrows. The spine of their aluminum core was always stiffer than the rest of the shaft. We'd float the the bare shafts in a tub of water. The spine would always rotate to the 6 o'clock position since it was heavier. Then we'd mark and fletch the shafts relative to the spine, so they all flexed exactly the same coming off the bow. It made a noticeable difference in how well the arrows tuned and grouped.
I don't know if that still applies to today's all carbon shafts, or not. It seems they should have a consistent spine all the way around, but I'm not sure. May be worth checking out.
Matt
What spine are your shafts, and your draw weight?
300 spine and 73lbs....29.25 draw length. I'm on the edge of being under spined but was hoping to make them work. When I purchased these shafts last year I was shooting 70lbs. I wasnt planning on buying a new bow this year... it just kinda happened!
Try cutting an inch or more off and use the 100 grain point to mitigate the weak spine issue and to check for that. Or use another aluminum insert behind the front one. Or both. You are border line and that's never good.
I've spine checked many dozens of 5mm Axis shafts on a spine checker and so seldom found a "bad" one that I quit. Shoot them all and if you do get a consistent flyer, put a blunt on it and use it for field practice.
Ambush... I'll give that a try and see how it flys. And I'll also make up another one just to see if the 1st was an anomaly.
Thx to all for the input !
You might be underspined….try it with a 100g point
i shoot the same shaft, same length and I was underspined with 75/145. When i went to std inserts I was good…
Instead of cutting them just decrease the centershot 1/16" at a time. That will stiffen them dynamically.
Beendare... same results with 100 grn just not as bad of a tear. The tear continued to change location as I rotated the nock at 90 deg increments.
My guess is you are under spined.
I shoot the same arrow with a 31” draw, 72 lbs and 28.5” Carbon to carbon. 3 - blazer fletch with a Hit insert and 125 grain head.
When I first bought this bow I was shooting 340 Axis arrow and 100 grain tips. . Had to turn the bow down to 63 lbs before I could get them to fly good.
Before cutting and building just try turning the bow down to see if it is a spine issue.
I just got done nock tuning some arrows and based on that experience and your setup, I too believe you are under spined. You have alot if weight up front for that length & spine of shaft.
If you want to stick with those components, I suggest cutting it down a little at a time to clean up the tear. Or turn poundage down 1st to test it out b4 cutting.
I would heed Frank’s advice and move your rest out a little bit at a time. That may not give you the final answer that you want, but it will tell you if weak spine is at the root of the problem.
I personally don’t really have an aversion to cutting shafts down in length, but it’s so hard to put it back on when you overdo it. If you think the shaft is weak, you can prove that out with centershot or point weight adjustments before firing up the cut-off saw.
You can turn the arrow upside down without turning the nock in relation to the shaft. This will tell you if it's the nock or the arrow.
Lets find the real problem before we try to fix anything.
FOC is too low… According to some guys it should be 96% foc. :)
All kidding aside 1 arrow isn’t a good enough sample. Some times you’ll just have a “bad” arrow maybe that’s the one
I have shot axis for the last ten years no complaints. I decided to shoot the original snuffers I shot years ago, knowing full well they might not be consistent, they flew like crap. I decided to screw them on some maxima reds I had dam if all 6 shot great.
1st thing I did today was change out the nock and shot it a few times.... Way way better! So the brand new Nokturnal must be bent.
Flight still isn't perfect. I'm going to make some of the suggested moves made here and see how much more I can improve it.
Thanks for everyone's suggestions! Shoot straight! Fuzz
