Spin Spin Spin

Bruno-TL · Post by **Bruno-TL** » Tue Aug 21, 2007 9:31 pm

Sounds like a dumb question but I hear guys talk about spin testing their shafts and heads. I try and I just don't see any difference between shafts and heads. What am I doing wrong? What exactly am I looking for?

Thanks

wabi · Post by **wabi** » Tue Aug 21, 2007 9:33 pm

Hard to describe, but you will usually be able to se a slight "wobble" where the back of the broadhead touches the insert if alignment is off.

sumner4991 · Post by **sumner4991** » Tue Aug 21, 2007 10:28 pm

wabi is right . . .hard to describe. What I do is look at different angles. When the broadhead is perfect, just look closely at the tip. Spin it fast, the tip will look like a point, not fuzzy or wobbly. I had a couple of broadheads last year that were cut off center, everything looked great except the tip. Hopefully, you have an adjustable spinner . . .if so, then you can change the length to check the straightness of the bolt. Anyway, if you have a good spinner and you are looking closely and don't see anything . . .then that's a good one. If you have a old bolt or arrow laying around that is slightly bent, then spin it . . .then you will see a difference.

pokynojoe · Post by **pokynojoe** » Wed Aug 22, 2007 4:57 pm

I agree with bstout. Test the arrows in a vertical postition for broadhead alignment. I spin the point on a piece of tile. A shaft spinner won't really tell you if your broadhead is concentric.

For example in preparing my hunting arrows for this season I chose to use some 1916 Legacy with glue in/glue on inserts and Zwickeys. When checking shaft straitness, everything seemd fine, however when spinning vertically, there was noticable wobble at the broadhead base and insert. This just required some re-heating and turning until the wobble was gone. Not noticable on a shaft spinner.

Regards
Joe

gad · Post by **gad** » Thu Aug 23, 2007 9:10 am

bstout wrote:Yes! You hold the shaft with hunting head attached in the vertical position (straight up and down) with the tip of the head on a hard surface like formica.

Then you spin the shaft looking for concentricity at the junction where the arrow head and shaft meet. There should be no visible wobble. Sometimes you can try a different screw in head and it will match better to one shaft/insert than another. The best thing to do then is number the head and the shaft so you don't get them mixed up.

This is how you check hunting head/front insert alignment to the shaft.

The spin tester (horizontal) is for checking the shaft itself. It won't tell you much about the head/front insert alignment. In other words if you can see wobble at the head/shaft junction while in the spin tester you're way the heck off.

The spin tester jig is for checking the shaft itself for straightness.

The spin tester (horizontal) can tell you if the head/front insert alignment is / is not good. Just put a little amount of mass (could be that mass that childrens use to play) on the front of the shaft and stuck the smallest possible portion of the BH ferrule into the mass. Then spin and check if the hole on the mass is the same diameter of the ferrule portion you have stucked in the mass. If the hole is bigger, than yes, your broadhead is wobbling or your shaft is not straight.

sumner4991 · Post by **sumner4991** » Thu Aug 23, 2007 9:30 am

gad . . .I agree . . .you must focus on the tip. It should be spinning to an exact point. It will look crisp and clear . . .not fuzzy.

gad · Post by **gad** » Thu Aug 23, 2007 12:41 pm

bstout wrote:Gus: I hadn't heard of that method before but I can see how it would work. Sort of seems like a lot of trouble though.

The vertical spin test doesn't require any test equipment. The vertical spin test can be performed almost anywhere even on a flat rock out in the woods in a pinch.

Having the tip of the arrow head exactly concentric with the shaft isn't nearly as critical as having the ferrule in its entirety in-line with the shaft. Many broadheads get a bad rap for flying poorly (Wrongly blamed for planing) when the real culprit is the person that installed the broadhead.

Yes, I understand your method of test too. Thank you for sharing your knowledgment too. I will try your method together with mine, I believe most of us will achieve perfect BH flight.

sumner4991 · Post by **sumner4991** » Thu Aug 23, 2007 1:04 pm

The vertical spin test doesn't require any test equipment. The vertical spin test can be performed almost anywhere even on a flat rock out in the woods in a pinch.

Bob . . .how do you hold the bolt verticle and spin it on a rock? Use your finger? Are you holding it exactly vertical? I need to know how. I just don't see how a vertical spin would uncover flaws that a horizonal spin tester(if used properly) would miss. Maybe I just haven't come accross that problem yet. Also, how do you test to see if the bolt is straight? Thanks.

sumner4991 · Post by **sumner4991** » Thu Aug 23, 2007 4:26 pm

Bob . . .very good, I'll give it a try.

Thanks.

sumner4991 · Post by **sumner4991** » Fri Aug 24, 2007 10:06 pm

Bob . . .thanks for passing it along. I bow hunted in the late 70's, then had to give it up for various reasons. I started bow again last year. I never heard of this technique. I used a Bear Whitetail Hunter compound bow back then. I never tested my broadheads and still had a ton of success. I apparently was extremely lucky to harvest the amount of game I took. I know it wasn't because I bought the most expensive equipment on the self because I was dirt poor. Whatever was cheapest is what I bought, thus the reason I had a Bear Whitetail Hunter. Anyway, I'm glad you didn't just assume everyone knew about this and didn't post. I am in the process of building my bolts for the coming season and will definitely put this test to use.

Everyone . . .please keep the information flowing, that's what this forum is all about . . .sharing the knowledge.