Clocking Arrows
Equipment
Anybody doing this? My Son-in-Law was telling me about it last night. Theory is that bows naturally rotate an arrow in a certain direction. Deciding on a left or right helical would depend on the natural turn. True??
Yes, it is true, have experimented with bare shafts and proved it to myself. As to cause, near as I can tell it supposed to be from the direction of the serving wrap, it imparts a slight spin to the shaft.
Just a question....
If you can index your nock somehow, let’s say that the index started at 12 and ends up at 4:00 compared to where it started.
Did it rotate 120 degrees to the right or 240 to the left?
Just askin’. But you know, the last time this came up, somebody claimed that they had seen high-speed video proving that an arrow came off the string, started rotating in one direction and then reversed as it traveled down-range.
Of course, I’ve seen video that “proves” that an automobile travels down the highway at 80 MPH with its wheels rotating backwards....
I suppose it’s conceivable that the “threads” on the serving might impart a minute amount of rotational force via the nock, but compared to a fletching? That’s like a skinny kid on a bicycle T-boning a speeding locomotive and knocking it off the track.
I’m not saying that arrows don’t rotate without fletchings, but I’m not buying the argument that putting clockwise fletching on an arrow that “wants” to spin counter-clockwise will ever make a damn bit of difference to anything...
And anybody who thinks he’s a good enough shot for it to matter... ROFLMAO
The test I saw on video the guy had a thread hanging on the shaft. It wound around the shaft showing direction of rotation. I too can't believe it makes enough difference to offset the spin from the fletch.
Indexed the arrow and shot close to the target. Natural spin was left. If going with a left helical continues the spin in that direction, why not? If it improves accuracy even a tiny bit, wouldn't that be a good thing?
The left helical causing your points to un-screw is a bigger issue than fletching for any “natural” rotation
gf you do realize that a video camera and a high speed camera are 2 different things right? Your wheels spinning backwards thought process doesn’t work with a high speed camera like what Levi used to prove the point your trying to disprove.
Arrows will naturally spin one direction, twist of string or serving isn't what does it; nobody knows exactly, different arrows from the same bow can and do rotate different directions. If you fletch opposite the natural spin they will stop rotating when the fletch takes over and reverse. Hyperspeeds out of my reckoning reverse at about 10 yards. It takes all of 5 minutes to see it yourself. Does it matter, nobody has proven it makes any difference at the end of the day.
Ambush - please explain. I am truly interested and not picking a fight.
We had a guy in our club a few years back who was known for over-analyzing everything. He was the classic guy who had three times as much time and money than he did common sense. He spent an average of four hours a day with his bow on the shooting machine. Nice enough guy, and he shared all of his results but,...most of the results were common knowledge already. Anyway, to make a long story short, he was convinced that this natural arrow rotation would improve his shooting. It was the reason he built the shooting machine in the first place. Turns out, each of his arrows hit the same dime sized hole indoors at 20 yards no matter if the arrow had three left helical, three right helical, four-fletch, two-fletch or a three-fletch with one stripped off and missing. All the arrow needed was enough drag at the rear to keep the back end of the arrow in the back.
Now, if you throw a big fixed blade head on the front, you're going to want some rotation along with that drag so the arrow doesn't take a hard left or right planing into the air. Which direct that rotates does not matter. The results this guy had showed that his bow naturally turned the arrows counterclockwise. His arrows did one rotation to the left at 20 yards naturally as a bare shaft based on the string wrap test. With left helical feathers his arrow completed one rotation at 10'. With right helical feathers his arrow finished one rotation to the right at 13'.
In conclusion, yes, matching the fletch orientation to the natural spin does make the arrow get to one revolution quicker. No, it did not have any affect on the grouping location or group size. If you can't tell the difference in a controlled environment with a shooting machine, you certainly won't see any real differences shooting by hand. The only advantage would be psychological. The bid disadvantage is spinning your target points free every time you shoot.
Foob-
I saw the video where the arrow appeared to reverse the direction of its rotation, and if you want to believe that the optical illusion created by filming a rotating object at X frames/second somehow magically evaporates at 2X or 10X or 150X, I’d love to see you explain that.
And if you want to believe that the forces that drive an unfletched arrow to spin through the the air are enough to start a fletched arrow spinning in the wrong direction, I guess I’m not gonna argue with you.
As for the thread wrapping around a bare shaft... how much you wanna bet that you could tie a thread to a shaft in a wind tunnel and you would see the thread wrap around a (fixed/non-rotating) shaft at least some of the time? It might be interesting to test to see if the threads wrap in the same direction every time, too. And of course you’d have to repeat that experiment after swapping ends on the shaft and the thread as well, because thread has a “thread” to it just like a screw... or a carbon arrow.
Better test aluminum, too...
Again... I’m not saying that a bare shaft won’t spin; I’m just saying that there’s no chance in hell that you could ever demonstrate a difference in accuracy or velocity between arrows that are fletched to match how they “clock” or not.
JB, if your arrow is spinning left hand, when the point hits, it will resist the rotation of the shaft and the right hand thread will un-screw.
On a broadhead entering an animal, this means the head will lose the support of the shaft end.
Nobod said there was a difference in accuracy. What is being said and proven a thousand times is an arrow has a natural rotation out of the bow, and, If the arrow is fletched opposite that rotation, the arrow will come out of the bow spinning it’s natural direction then reverse when the fletching imparts enough drag to reverse it.
Ambush - thank you for the explanation. I wouldn't have thought of that.
Not sure I buy the “proven a thousand times” thing, Bob...
But I suppose (in principle) that as a nock slides across the serving during separation, there might be a jot of Up force applied to one side and a tittle of Down to the other... for the millisecond that it takes for the nock to slip clear...
Oh, wait... Nope. Let’s see... 260 FPS X 12” in a foot is 3120 inches/second and let’s call it X 5 if there’s about 3/16” of sliding across that serving... that would be... 0.06 msec during which those forces would be applied. Except for at least half of that time, the string would still be deep enough in the nock to prevent any rotation from occurring whatsoever.... But I suppose you could test by shooting some bare shafts and then inverting the string to reverse the effect, and then maybe a string with heat-shrink tubing for a serving as the control... maybe shim to fit with some PTFE pipe tape.... ;)
But then you fletch it, and since the aerodynamic forces from the fletching (these being a function of velocity) are at their absolute max during separation from the string, and since they’ve been straining against the nock & string for the bulk of the power stroke...
OK... I guess I might concede that the nock & serving can team up to put a smidge of spin on a bare shaft.... but I gotta tell ya... I just can’t see that amounting to anything when it’s put up against any substantial amount of fletching...
But who knows... maybe somebody with a shooting machine and a whole raft of super-high-speed cameras can prove me wrong. Plastic nocks and serving material are both a helluvalot denser than air...
GF, the 28'ish inches of power stroke is something I didn't consider. You are right in that the vanes are actually "loaded" straining against the string trying to rotate. In affect even giving a little boost to rotation as they regain their shape beginning immediately when the nock clears the string. So a bare shaft that has a "tendency" to spin left, when fletched right, will not come off the string spinning left then change rotation to right. Good catch!
I guess I should add to acknowledge the possibility of "natural rotation" having "some" counter effect: a bug hitting your windshield doing sixty MPH (the car not the bug) will in theory slow the car down.
GF, you could prove it to yourself in 5 minutes. Some of us actually test this stuff. My hyperspeeds with 3, 2.250's reverse at about 10 yards.
Some of you guys may remember Bowdad. He was a friend of mine and I watched his son tune his bow by shooting arrows with no fletching at 20 yards. When he got it tuned the arrows would be perfectly straight in the target. He did some tournament shooting.
This one fell prey to a bare shaft (cedar) at 17 yards.
This one fell prey to a bare shaft (cedar) at 17 yards.
Ummm... I tune by shooting bare shafts at 20 yards and I’ve broken plenty o’ nocks and even got a Robinhood in the process.
And I’m shooting fingers.
This topic reminds me of an old Styx song called too much time on my hands
Bou, you could say that about lots of threads.
The arrow rotation I find interesting in that I never heard of it for 30+ years till last year. Now I've heard it half dozen times. I've never tested my arrows and right now my BH and FP are hitting the same, so have no plans to mess with it. I watched a video with Burnworth, he shoots an arrow with BH and blazers through gel medium. His arrows left bow rotating clockwise and passed through the gel and came out other side rotating counter clockwise.
To answer the OP's question: Yes I've heard of it. Yes I test it out of my recurves. Yes I fletch accordingly. Works for me, YMMV and I don't care to debate it. I test and shoot how I like, you all do the same. Be safe and shoot straight.
This is the first I've heard of clocking arrows. Interesting, but it won't make me chance the way I am doing things at this time.
“ His arrows left bow rotating clockwise and passed through the gel and came out other side rotating counter clockwise.”
Curious to know how that was documented.... (I can figure out the part in the gel ;) )
So does how you put the string on your arrow affect rotation? What if my string is not perfectly round and it induces some amount of spin on my shaft? This could be up there with life’s greatest mysteries.
^^^ ... and how do they get the filling in the Cadbury chocolate bar??
So if I’m reading correctly, some of you that “test and fletch accordingly” have arrows fletched left and right in your quivers ??
Same arrows turn the same way; my gold tips turn right, X27's turn left, victory nvx 23's turn left, haven't shot the v-tac 23's yet. When I refletch for hunting that arrow gets fletched to turn right regardless.
GF, its a video on youtube. Search Burnworth and Bohning Blazers. If you'd like to watch it.
Bob, from that we can say that it is the shaft and not influence from the bow or shooter. In other words, if you dropped the shaft from the top of a tall building, it would immediately start rotating at release. Would rotation accelerate over distance?
It might be the shaft composition and mfg process that determines the way it spins, it could also be a spine issue since virtually any arrow will bend as it's being pushed by the string, I don't know and those that insist it's "only" the string twist have been proven wrong. That said, you can invert the string and the same arrow can/will exit twisting the opposite direction. Nobody knows for sure, it doesn't, or hasn't, made a difference on the score card at the end of the day. When I fletch the tac 23's I'll probably go back to rh rotation, fletching lh just seems odd and it definitely made zero difference for me.
Look at Nestly's high speed footage of bare shafts, field points, various broadheads, left and right wing, etc under "High speed broadhead video - Archery Talk, September 26, 2019".
That video shows why I've been preaching to minimize your arrow rotation until you have just enough to steer your broadheads and nothing more. Hitting that gallon jug of water stops the rotation every time. That sheds off valuable energy needed for penetration.
I cringe every time I hear about putting the maximum amount of helical on their fletching jig.
Watch this one, really interesting on fletch angle, rotation, velocity, etc. "Fletching Spin Test 2019-11-26 by 1nestly" on Youtube from 11/26/2019 Testing spin rates of various fletchings and fletching angles.
