Author Topic: Diagnostic needed (Read 4367 times)

DC · « **on:** December 09, 2014, 05:15:36 pm »

I have a bamboo arrow that flies like a badly thrown spiral. The point goes OK but the fletching seems to rotate/wobble around the centerline. One of the fletchings was not quite at 60 degrees so I fixed that, no difference. It had a 125 gr point, I tried a 100 gr and a 140gr, no difference. It spines at 30 lbs and the bow is 37 lbs. I could just turf it out but this is the kind of thing that I learn from, if I can figure it out. Any ideas?
Thanks
Don

Pat B · « **Reply #1 on:** December 09, 2014, 05:33:00 pm »

Are all the feathers from the same wing, right or left? Is the stiff side of the shaft against the bow?

DC · « **Reply #2 on:** December 09, 2014, 05:50:16 pm »

Yes they are from the same side. The cock feather is from a different bird. Two turkeys and one goose. I need a little clarification on the "stiff side". When I spine it with the cock feather up I get .875" deflection. If I turn it 90 degrees I get .850" deflection.

bow101 · « **Reply #3 on:** December 09, 2014, 06:28:12 pm »

Would like to help ya Don but you know I use all wood shafts so a lot of the guess work is taken out of the equation. almost sounds to me that the last 8" of the shaft is to light. I have yet to shoot those Cypress shafts.

BowJunkie · « **Reply #4 on:** December 09, 2014, 07:39:38 pm »

Your arrow may be to light and not correctly spined for the bow. You say the arrow is spined at 30lbs and the bow for 37lbs.
Try pulling a few inches just short of full draw, and see if the tail wobble calms down. If it does your arrow is not stiff enough to stabilize it's self in mid flight. Also keep in mind with a under spined arrow, if your knock point is slightly too high or slightly too low it will exaggerate the the up and down wobble along with the side to side wobble, making the tail of the arrow wobble in a circular motion. Your knock point should be just slightly above center line of where the arrow rests on the bow. You will have to fine tune this center line for your specific bow, by walking the knock up or down the string. Once you find the sweet spot mark it, measure it and make note of it. Every bow will be different.
By the way,,, what is your draw length???

Danzn Bar · « **Reply #5 on:** December 09, 2014, 07:54:04 pm »

I think BowJunkie is on the right track...
DC, just remember when trouble shooting, only make one change for every shot, too many changes at one time confuses things.

DBar

DC · « **Reply #6 on:** December 09, 2014, 08:22:28 pm »

27" I'll try the short draw idea. I could also over draw a bit.

I thought I'd posted this. Oh, well. I went out and got in a couple of shots before it got to dark and the skies opened again

. It seems to wobble no matter what I do. Short or long draw. I'll try again in the morning(weather permitting). If nothing jumps out at me I'll bare shaft it and start from scratch

mullet · « **Reply #7 on:** December 09, 2014, 08:29:57 pm »

A very easy way to tell the stiff side without a spine tester is to spin it while supported at an angle.

Lean one end on the floor and the other end supported against, say, a Coffee Table at an angle, (45); push down with your palm enough to make it bend slightly and try to roll it.

When you reach the stiff side it will "flip" very fast. You can now do it again since you have the feel for it and mark that side and put it against the bow when you cut your nocks.

Danzn Bar · « **Reply #8 on:** December 09, 2014, 08:55:56 pm »

Quote from: DC on December 09, 2014, 08:22:28 pm

I thought I'd posted this. Oh, well. I went out and got in a couple of shots before it got to dark and the skies opened again . It seems to wobble no matter what I do. Short or long draw. I'll try again in the morning(weather permitting). If nothing jumps out at me I'll bare shaft it and start from scratch

Sometimes doesn't matter what you do, I've had natural shafts (Cane/Boo) that just won't fly worth a darn no matter what, and now I sell them for wall hangers

, Learned that from Mullet (Eddie)

DBar

DC · « **Reply #9 on:** December 10, 2014, 03:53:10 pm »

I changed the fletching and it seems much better. I still don't know what was wrong with the fletching but I'll take it. The final test will be at the range next Monday. I can only shoot about 10 yds in my back yard. Thanks for the help.

PEARL DRUMS · « **Reply #10 on:** December 10, 2014, 04:18:00 pm »

Another quick trick is to turn your cock feather in. If it flies good your arrow was just made 180 degrees off. Take the feathers off and glue them on again, but opposite.

Pappy · « **Reply #11 on:** December 11, 2014, 07:10:58 am »

How long is the arrow total, anything over 28 in total length will weaken it by 5 so if it is 30 inches total it is a 20 lb splined arrow and so on.

Pappy

Badger · « **Reply #12 on:** December 11, 2014, 02:30:17 pm »

I have that problem on very light flight arrows quite often. We don't have any point weight on a flight arrow. Sometimes I can correct it by raising my nocking point. At times I have had to go up as much as 1/2". What is your tillerlike? Do you have excessive negative or positive ( more than 1/4") ?

DC · « **Reply #13 on:** December 11, 2014, 03:04:03 pm »

The arrow is 29". The tiller is actually within 1/16". I got lucky. This arrow shot fine on a 42ish # bow. Like I said I'll wait til I can shoot it at the range to see if the new fletching fixed it. Meanwhile I'm starting to wonder how much the arrow pass offset would affect this. The handles are close to the same width but I'm not sure about the string alignment.

Pappy · « **Reply #14 on:** December 12, 2014, 05:11:56 am »

It will effect it a lot.

Pappy

Primitive Archer