Those that use 4 fletch, which angle is the best 120/60, 75/105?
Personally, I like the 90x90x90x90.
I have recently done some testing with 4 fletch and my fletcher makes the 75 / 105. This set up has been working good for me, I have not tried the 90 / 90 so I cant say about it. Also I cant tell a big difference between the 3 and 4 fletch with field points or broadheads.
I space them evenly.....and here's why.... a 4 blade boat prop is spaced evenly for a very important reason....if two blades are too close together, one will rob water from the other, and the prop will not grab water evenly and it will loose stability and cavitate....like prop wash in jets.
If you have feathers too close to one another, one will grab more air than the one behind it....defeating the purpose you are after....stabilization. Not saying other arrangements wont work....just saying if you want the most stabilization, then even spacing is going to give you that.
Never had clearance problems with them space evenly either....I like the 'no look nocking' feature though.
4 x 90 for me too. The most important reason is that this looks waaaaay better, but I like Terry's explanation as well. ;)
4 x 90, 4" naners is what I have been using for the last couple of years. Did some experimenting with 4 x 60/120 and 4 x 75/105, both in 4" naner as well but did not notice any different in flight so just ended up sticking with 4 x 90. Your feathers are going to make contact with the shelf no matter what you do so shoot what you prefer.
What Terry says makes sense but I personally never noticed any difference in the 90, 60/120, 75/105 when I shot them.
Good luck
QuoteOriginally posted by Terry Green:
I space them evenly.....and here's why.... a 4 blade boat prop is spaced evenly for a very important reason....if two blades are too close together, one will rob water from the other, and the prop will not grab water evenly and it will loose stability and cavitate....like prop wash in jets.
If you have feathers too close to one another, one will grab more air than the one behind it....defeating the purpose you are after....stabilization. Not saying other arrangements wont work....just saying if you want the most stabilization, then even spacing is going to give you that.
Never had clearance problems with them space evenly either....I like the 'no look nocking' feature though.
That makes more sense than just about anything I've read regarding fletching! ;)
What Terry said makes a lot of sense, but the 75/105 fly very straight for me.
Dan
For decades I've always used 75x105 because of feather clearance, but these new low profile feathers have changed my thinking and I'm now fletching 90x90.
(http://www.tradgang.com/rob/4f.jpg)
What Terry said. I talked to easton arrows years ago. He told me the most important thing was spacing them evenly.
There appear to be two possible benefits from four fletching rather than three:
1. Improved guidance by more fletching surface using feathers/vanes you would have used for three fletching, or smaller feathers/vanes to achieve identical guidance which should yield slightly improved arrow speed;
2. Quicker subsequent aimed shots because feather/vane location can be no longer cock-feather dependent. No one seems to count this benefit as worth much effort to achieve.
QuoteOriginally posted by Naphtali:
There appear to be two possible benefits from four fletching rather than three:
1. Improved guidance by more fletching surface using feathers/vanes you would have used for three fletching, or smaller feathers/vanes to achieve identical guidance which should yield slightly improved arrow speed;
2. Quicker subsequent aimed shots because feather/vane location can be no longer cock-feather dependent. No one seems to count this benefit as worth much effort to achieve.
And if you chop/burn, ya need just two feathers per shaft instead of three. ;)
I shoot cock fletch in so when I switched to 4 fletch I fletched them cock in and the outside hen feather.The feathers are 4" so I can get 2 out of a full length feather most times anyway.
That configuration is also used by Roger R. and is described in Masters of the Barebow 1
I'd bet ease of manufacturing has much more to do with blade placement on a prop than even distribution and your also talking about thrust vs stabalization.Unless you've got so much helical that the back half is behind the front section of the feather next to it all feathers will recieve the same resistance as it travels down range
I've been using 4-fletch at 90 degrees for a long time now. No clearance problems at all.
Terry, your idea is good but your analogy is flawed. A boat prop has to maintain balance, uneven spacing wouldn't allow this. A prop is moving water for foward motion. Fletching is moving air to cause the arrow to spin.
Biggie,it would still be balanced LOL and it would still have the same surface area coming in contact with water/air
As for clearance it really shouldn,t matter at all no matter where it is unless ofcourse your not spined right in the first place.
I've shot 4" vanes off the shelf of my LB cock in with a BH up front and if I don't goof the release it clears no problem
no way...put a 60-120 set up on a propeller and see how long your lower unit lasts.....
plus...the specific gravity of air won't permit the amount of cavitation that the specific gravity of water will.
Holy moly; them's big words!
I do it like Biggie and I do that because Roger R. said so! I wish I had time to test everything so sometimes I just have faith and trust those that have. 60x120 works good here.
I am going to see Roger hopefully next w/e and will ask for some particulars about the various 4 fletches and report back...
it's funny though cause I have to turn my nocks where a feather is on like a 45 degree angle to the riser to get perfect arrow flight....
So a 2 blade....LOL never mind
Good luck!!
QuoteOriginally posted by swampbuck:
I'd bet ease of manufacturing has much more to do with blade placement on a prop than even distribution and your also talking about thrust vs stabalization.
Nope and nope.
Sorry Biggie...there is such a thing as 'clean air' and 'dirty air'.
Two race cars can go faster than one for the very same reasons in reverse.
Yeah but you don't have one feather in fornt of the other but side by side. It's pure physics.
Drag is defined by surface area plus angle. How far apart the feathers are doesn't change anything unless one is ahead of the other.
As far as props go...balance must be maintained to realize maximum revolutions.
"Yeah but you don't have one feather in fornt of the other but side by side. It's pure physics."
Yep, as you don't have one prop in front of the other but side by side....for the very reasons I listed above....it's pure physics. :D
Lets go huning....I'll bring the Krispy Kreams. :p
I shot 3-fletch for years and always wore out my velcro rest about every 2 weeks. Now I shoot 4-fletch 60-120 and haven't had to change the velcro in 3 months. It worked so well that I never tried other configurations of the 4-fletch.
Sorry folks, but I gotta agree with Biggie on this one! And it ain't cause he's big and Scary.
I just discussed this subject with a Bowhunting friend who is also a tool and die maker. He says, that an arrow first of all with about 11 degrees of helical fletch only makes one complete turn in about 6 ft. of travel ,where as a prop would turn thousands of times in 6 ft of travel. Two totally different mediums, there is no comparison between the density of the 2 mediums, a prop turns so fast that it can displace water faster than it can move back into the prop ( cavitation) an arrow is already moving in air and not fast enough to cause a vacuum which would be(cavitation in air) . now,having said all of this, i don't think that there's much difference in any of the 4 fletch positions except that i believe the feather wear would be greater on the 4-90's.
N.B This is just my opinion and i'm only trying to get people to think not start an argument, this is what i love about this site!!
Sergio
I have a Jo-Jan which you can 4 fletch by turning the nock indicator around. I don't know what the degree is (maybe somebody would know) but they didn't shot that good.
Tried the 60-120 with the Jo-Jan and they shoot great.
Forgot to ask, what fletching jig do you use for the 4 90s. Thank you.
Alan; The Jojan does 3-120 or 4-75/105 .Also 60/120 will give you the best feather clearance on a shelf rest. I use an elevated rest and get good clearance with any pattern. Have fun with which ever you use.
QuoteOriginally posted by The Whittler:
Forgot to ask, what fletching jig do you use for the 4 90s. Thank you.
I use a BPE.
QuoteOriginally posted by SERGIO VENNERI:
He says, that an arrow first of all with about 11 degrees of helical fletch only makes one complete turn in about 6 ft. of travel ,where as a prop would turn thousands of times in 6 ft of travel. Sergio
No reasonably pitched 3 or 4 blade outboard propellor will require thousands of revolutions to push a boat forward by 6 feet. Let's do some math here. My 16 foot inflatable with a 40 hp 2 stroke easily does 30 mph at wide open throttle (~5000 rpm). There are 880 6 foot lengths in every mile, 30 miles is 26,400 6 foot lengths that are being covered every hour, which is 7.333 6 foot lengths every second. At 5000 rpm the prop is spinning at 83.33 revolutions every second, which means that the prop rotates a total of 11.368 times for every 6 feet it pushes the boat forward.
What's this got to do with arrow flight? :archer: - I have no idea, but I couldn't let that one go without some analysis. :archer:
You guys crack me up with all this "physics" talk.
I think I'm going to try some four fletch, just because they look neat.
-Vig
I straight fletch at 75x105 and have excellent results at ranges to 30 yards (my hunting limit and more). When I lob shoot I use three fletch helical as they maintain arrow performance (certainly not my performance) out to the 130+ yard targets. Because I straight fletch, I believe that the stabilization effect of the air on each feather is equal and consistant. This may not be true for helical fletchings. Of course, my PhD in physics was found in the bottom of a cereal box. :biglaugh:
-Brett
Stupid question time-----If you use 4x90 fletching do you use Helical or a straight fletch?
QuoteOriginally posted by the elf:
Stupid question time-----If you use 4x90 fletching do you use Helical or a straight fletch?
Helical, offset, straight - all yer choice. Experiment!
LOL you guys crack me up sometimes
My fletch's are practically touching each other on my skinny carbon arrows...I looked from the point end down the shaft and could see the whole profile of the helical fletch on all 4 feathers
You have X"s of surface area at X deg's
straight or helical doesn,t matter either
you only have what you have and where it is on the shaft assuming symetery doesn't matter
So now that we got that cleared up LOL and we all know that geese fly in a V shape for arrow dynamics but did ya ever notice that 1 side is longer than the other???
know why that is ????
There's more geese on one side?
QuoteOriginally posted by Biggie Hoffman:
There's more geese on one side?
Ya know, I've always noticed that the geese flying V is rarely uniform, always staggered ... ?
I think the geese are considering wind direction, one side of the V provides easier flying in a cross wind.
I have shot 4 fletch both at 90 degrees and 60x120 degrees extesively, the only difference I can see is that the 60 120 shows less wear on the feathers tips, flight characteritics appear equal to me. So I have been shooting 60x120 mostly because of the wear difference. The Bitzenburger fletcher does all the fletch options.
Biggie's got it LOL
sometimes the answer is more simple than our minds let it be