Two fletch

[DC]

I've given this some thought and it seems to me that mostly fletching provides drag to keep the back of the arrow at the back, so to speak. I think they provide some steerage but I don't think it's all that much compared to drag, That said, I think it's the amount of fletching in frontal area and surface area that makes the difference. So two feathers would have to be bigger individually to provide the same total drag. The more feathers the smaller they could be. Two fletch would be easier to make and use. I made some two fletch with masking tape for my grandson and they fly pretty well, especially considering  the number of wrinkles I got in the tape. But rocket scientists still use three fins to stabilize their rockets. I 'm sure  they would use two if it would work as well. Would you make the fletch 90 degrees to the nock or parallel to the nock? Any input would be welcome

[TSA]

Pat should answer on here- i have seen him build a bunch of 2 fletch arrows-
when i have built the "south eastern 2 fletch" i have always set the feathers up so that they are at about 30 deg. so the bottom fletch would just clear the shelf/ knuckle, if the fletch area was sitting on the shelf section of the bow!!
But i do that, knowing that upon release, the fletches never touch the riser or shelf at all anyway, if the arrow is tuned properly that is.
i do it anyway, even though i know it makes no difference anyway. Guess they have to be stuck somewhere- and thats as good as any position!

 so the short answer , IMO , would be to put them how one fancies, and not to be concerned about it.

[DC]

That's funny, for some reason I was thinking that there was only the two choices, 90 degrees or parallel. Mental block I guess. 30 sounds good. That gets rid of one question. Now how about 2 versus 3? I know a lot of guys use two fletch with no difficulties. Does that mean that the fletch on arrows relies more on drag than steerage? Rockets all use three or for fins, why not arrows?

[TSA]

DC, thats a good question.
 as a youngster i built rockets and we had a software programme- that you would put your design parameters in, and then it would tell you how it would fly, or not.
it was a great programme- as it didnt tell you what to do- one just tried all the funky designs- and then compare results, and then build the engines and the rocket etc- then go down to the field and scare the hell out of the pilots i guess- i made one that flew 1.6km in vertical height- i think we were breaking a few rules there

now the only difference i see is that the rocket doesnt spin, where even a straight fletched arrow will spin to some degree, due to greater  friction on one side of the feather than the other.
so with the rocket not spinning, a silhouette profile would  always yield the same profile irrespective of the angle.

i remember with the rockets- the bigger the fins the better they stabilized, but the bigger they were- the more prone they were to cross winds- same with arrows i guess.

for me, the better i can get my shafts tuned, then i can use smaller fletches- which equates to many  benefits.

bear in mind, these are just my thoughts, absolutely  zero scientific reasoning.

[DC]

I've been reading. Rockets rely on lift on one side of the fin or the other in order to steer. If the rocket starts to turn the angle of attack on the fin changes and it gets pushed back on course. In order to steer in any direction it needs at least three fins. If it just had two it couldn't turn parallel to the fin(if you can follow that jibberish). Now arrows with two fletches seem to fly fine. That makes me think that arrows don't use lift from the fletching, they just rely on the drag. Same way a blowgun dart relies on a ball of fluff. Knowing that arrows rely on drag to steer should tell us something. I'm thinking flight arrows. Do any flight arrows use two fletch. I'm thinking they could benefit on using on lift for steering rather than drag. now i have to read some more.

[TSA]

interesting, thanks!

now one starts to delve into the world of static spine vs dynamic spine, and why weight on the rear of the arrow ( 2 fletch vs 3 fletch) creates the opposite effect of weight on the front of the arrow

[Pat B]

For an Eastern Woodland style like I make, I place the forward edge of the fletch up and down but add a 1/4 to 1/2 twist over the length of the fletching, sort of like adding helical. I also lay the feathers so the back of the feather is against the arrow. The fletching seems to lay better that way.
 I have heard, but never done, hydrating the feather a bit first. This softens the quill a little making it easier to attach to the shaft.

[Hawkdancer]

Pat,
How high do you trim the fletch, and what shape?  Thanks,
Hawkdancer

[Pat B]

Here you go Hawkdancer this is one I did a while ago. These are secondary flight feathers. I also use tail feathers. The fletch on this arrow is 1 1/2", side to side. I've seeing them wider and narrower. You can trim to suit. If these arrows are tuned right will fly as well as any other.

 




I laid the fletching with the back up on this one. You can see how the bow of the feather holds it away from the shaft. With it mounted back against the shaft it lays flatter.