2" NAP QUICK SPIN VANES

bobbyvee · Post by **bobbyvee** » Tue Dec 11, 2007 8:41 pm

I've started using 3" quick spin on my carbon bolts. They seem to fly just as good as the 5", however I have not tried shooting my broadheads yet. I just put these together last evening and have only 2 done, but so far they seem fine. Have shot them out to 65 yds and they seen to be working fine. Will try broadheads tomorrow afetr work.

Pydpiper · Post by **Pydpiper** » Tue Dec 11, 2007 9:54 pm

There is more to a brass insert than just the added weight.
As an arrow spins it is rotating on it's axis, the center of the arrow. The farther away the weight is from that axis the more influence it will have on it's flight and the less susceptible it will be to external influences.
A cars flywheel for example, it is designed to assist in momentum, if that same flywheel was composed of two materials and had the majority of it's weight in the center (brass in aluminum) and very light on the outside (the part responsible for the energy) it would simply not do it's job correctly, or in different terms be less efficient.
This will only be apparent with a broadhead though. The more weight you have away from the axis the more gyroscopic inertia it will have. Crossbows are all about manipulating energy, inertia is just another variable that you do have control over.

Boo · Post by **Boo** » Tue Dec 11, 2007 10:22 pm

Bob, in the end you may just have to adjust your sights if you like the set up you have and it is consistent. Nothing wrong with that at all.

Cossack · Post by **Cossack** » Wed Dec 12, 2007 8:42 am

[quote="Pydpiper"]There is more to a brass insert than just the added weight.
As an arrow spins it is rotating on it's axis, the center of the arrow. The farther away the weight is from that axis the more influence it will have on it's flight and the less susceptible it will be to external influences.
A cars flywheel for example, it is designed to assist in momentum, if that same flywheel was composed of two materials and had the majority of it's weight in the center (brass in aluminum) and very light on the outside (the part responsible for the energy) it would simply not do it's job correctly, or in different terms be less efficient.

NOT brass in aluminum. Brass IN STEAD of aluminum. I'm talking about REPLACING the stock inserts or installing the brass ones when making bolts from scratch.
Apparently the brass inserts I bought are pretty uniform; all 12 bolts fly the same ... with broadheads.

Pydpiper · Post by **Pydpiper** » Wed Dec 12, 2007 11:10 am

Cossack, I wasn't addressing your statement, I use the same thing, couldn't imagine being without brass inserts. My statement was guided towards the guys that are using brass stock inside aluminum inserts. (read back a few posts)
This thread was started to help a guy bring his broadheads into alignment with his field points. That can happen in two ways, one is by luck the other is by getting technical with the arrows, controlling the things we can.
No two arrows or bows are going to shoot the same, every person is going to get different results, there are some things we can control though, and that is all I was pointing out.
Quick Spins will not help this problem (wont hurt either) but this broadhead/fieldpoint issue is not an accuracy problem. It is an easily solvable issue that has different roots than fletching.
The other option is for Bob to adjust the scope each time he switches, in that event a penny works great, come in packages of 50 and you can buy two for a dollar.

Normous · Post by **Normous** » Wed Dec 12, 2007 11:45 am

I just took a length measurement of my brass GT insert at 1.13" and the aluminum came in at .980". Even with a brass or steel insert securely installed my overall length for the aluminum/add on is 1.19" and 1.02" respectivly. about the same as the brass, Right?
The way I see it, there is no length difference between the the brass and aluminum add on ones. Both inserts will concentrate weight to the broadhead end (desired). Only the brass will be heavier. In my testing I found that my broadheads grouped very well with a insert weight between the brass and aluminum. Did the brass perform well? Yes they did, but minus fps, maybe a little too much for my liking. Did my aluminum/brass/steel add on preform well? Yes the did , much like the brass, but lighter and a higher fps.
I have even experimented by removing .25" from the brass to lighten it. Did that preform well? Yes, to that one as well.
Again is pays to experiment and come to your own conclusions to find the ideal flight characteristics prefered. And I still feel the aluminum/add on weight does not impart any negative flight characteristics to the bolt. I just like to tinker.

Pydpiper · Post by **Pydpiper** » Wed Dec 12, 2007 5:47 pm

enormous wrote: I just like to tinker.

LOL, I have seen what you call "tinkering", the rest of the world calls that hard core modifications. I only wish I had the abilities to do to a weapon what I have seen in your photos Norm.

Cossack · Post by **Cossack** » Wed Dec 12, 2007 6:20 pm

I guess it pretty much depends how much your bolts weigh when you start tinkering, enormous. The GTs minus 5" vanes and sans brass inserts weigh well below the minimum 350 grs. recommended by the mfgr. In fact, the one I shot caused the bow to make more noise than I was comfortable with. Sounded like a mini dryfire. Substituting the 110 gr insert give me only 45 grs over minimum. My bow and I can live with that.