Spine/Deflection Gurus.....

[Bud B.]

Spine Gurus,

If I were using a spine tester to show deflection on a 26" span, what should a 1916 shaft deflect using a #2 weight?

I have built a home made spine tester and I need a standard to check my accuracy. I have 1916s, 2016s, and 2117s.

Right now I'm getting .500 for a 1916 or roughly #52. I am not using any dials or swing arms, just a vertical drop-line pointed rod measuring against a 64ths measuring rule. I realize it is not precise, but so far I am pleased with my tests. I have a wood shaft that was spined at #52 by someone else. On my homemade spine tester it I got #52 also.

So far I have less than $5 in it.

If someone can direct me to an aluminum shaft chart using the 26" #2 method I'd appreciate it.

A real spine tester is on my long list of wishes.


Thanks.

[Hot Hap]

1916-.623
2016-.531
2117-.407

Don't remember where I got this. I printed them out years ago.

These were at 28".

Hap

[Bud B.]

Thanks Hap, but I think that's based on the 28" #1.94 rule.

I hope someone who might have the shafts I listed, and a 26" spine tester, can measure them and give me some feedback so I can get me a baseline of reading this thing. If I can get closely similar readings I can then move to checking wood shafts with a little more confidence.

My check of that known #52 shaft was spot on, so I'm trying to double check.

Thank you Sir  

[Hot Hap]

Someone on here had a conversion no. Don't remember what it is. You might try a search.

Hap

[CoilSpring]

From STU Miller on another site...

"Below are my number for Easton XX75 shafts measured with 2# on 26" centers....I think this is what you are looking for."
 
1416 1.386

1516 1.155

1616 0.883

1713 0.850

1716 0.726

1813 0.710

1816 0.619

1913 0.598

1914 0.542

1916 0.512

2013 0.495

2016 0.437

2018 0.384

2020 0.367

2113 0.437

2114 0.413

2115 0.380

2117 0.332

2213 0.380

2215 0.341

2216 0.309

2219 0.277

2312 0.351

2314 0.319

2315 0.279

2317 0.243

2413 0.299

2419 0.218

2514 0.249

2613 0.238

[Looper]

[Bud B.]

Yep. That's it!!

Thanks.

Can you PM a link from where you got that please?

Much appreciated.

Bud

[darin putman]

Well Bud B looks like you did pretty good for 5 bucks according to coil springs chart, how bout a little more info. on that tester you made, sounds bout right for my back pocket.More room for arrows always feeling the need for a few mor.

[CoilSpring]

Bud, PM Sent...

DP, What part of Killen are you from?  

[darin putman]

I live off brush creek road between hwy 43 and old hwy 47.

[Bud B.]

Scrap wood, perscription med bottle, coathanger, #9 lead shot - all free from other projects, reloading, and packratting.

I bought the two L brackets (can't remember price each) and the rule ($2.29 at Lowe's).

The lead in the bottle weighs exactly 2lb.

The rule has a slide on it and a fraction/decimal conversion chart on the flip side. I can adjust the rule at rest to be on an whole number. In the photo it was on 3" With the two # weight in place it is at 33/64ths, which converts to .515. So my first reading was off. My eyes are less accurate than the rule and wire pointer. I have a hole drilled at 13" so getting a good straight hanging pull is no problem. The wire hanger was made into a hook at the bottom, hooked near the top, and the top end ground to a nice heat treated purple pointed end.

Good enough for wood shafts, I'd say and my needs. Gotta keep the reading glasses nearby though

 

 


Blurry, but I think you can see the reading.

 

[Bud B.]

Originally posted by CoilSpring:
Bud, PM Sent...    

Got it!! Thanks!

[darin putman]

Thanks Bud I think I can handle that, probably got all I need laying around too.THANKS AGAIN

[Davesea]

Here's a link to some charts that will make the conversions
 http://www.rangersarchery.com/?q=chart

[tecum-tha]

Include a digital caliper to measure the deflection instead of the "ruler". Easisest and cheapest and has a button to zero it.

[Bud B.]

Maybe later. But for my needs right now this is fine.

[Bud B.]

Double tapping again. Sorry