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I've seen many videos on you tube about how to make a spine tester. They all say to put the bearings twenty six inches apart. But how far apart should the roller bearings be to find the stiff spine on a twenty inch arrow for a crossbow so it can be fletched correctly?
 

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Actually, for a vertical bow arrow, spacing is supposed to be 28", with a 1.94lb weight in the center to get your deflection value. If you're just wanting to find the stiff side, distance doesn't really matter, as long as your not trying to put a value (in thousandths) on the arrow. Obviously, the further apart, the easier it will be to detect the stiff, or weak side.
 

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X2 The weight can be more or less as well as long as your not comparing deflection values with some one else. I made mine at 18" and my weight is a little over 2lbs
 

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I've seen many videos on you tube about how to make a spine tester. They all say to put the bearings twenty six inches apart. But how far apart should the roller bearings be to find the stiff spine on a twenty inch arrow for a crossbow so it can be fletched correctly?
There is no set width needed you need to set it up to fit the shafts you are indexing. If you have only 20 in arrows make it 19 to 19.5 on center, 22 in make it 21 to 21.5 on center.

The weight needs to be heavy enough to show a variance with the shafts IE the stiffness. I have two weights the 1.94 that comes with the RAM and another one made by RAM they weighs about 3.8 pounds

The 1.94 exact weight is only needed if you are looking for accurate spine deflection
 

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I’ve viewed spine indexing and finding spine deflection as two different things. Classical spine deflection measurements are not possible with xbow length shafts nor or they needed. Most of us just use a spine tester to find the stiffest side. Jerry goes one step further in his spine matching that makes his arrows even more consistent. His spine indexed, spine matched shafts do provide more accurate arrows.

BUT YOU CAN DO THE SAME AND SKIP JERRY!
All you have to do is order a few thousand Spynal Tapps in 32” length 0.001” (for the full 32”), then find the most consistent spine portion of the 32” shaft for the 16.5-22,24” crossbow shafts, index the stiffest side of the few thousand shafts, then measure the weakest sides -not just indexing but measuring, then sorting these thousand + shafts to matched sets and that’s all there is to it.

Or, you can just a very small construction fee for unbelievably weight and spine matched arrows that will result in no culled arrows.
Or, you can make your own arrows but having the advantage of his matched shafts.
But, for the small construction fee, I just get completed arrows.
 

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There is no set width needed you need to set it up to fit the shafts you are indexing. If you have only 20 in arrows make it 19 to 19.5 on center, 22 in make it 21 to 21.5 on center.

The weight needs to be heavy enough to show a variance with the shafts IE the stiffness. I have two weights the 1.94 that comes with the RAM and another one made by RAM they weighs about 3.8 pounds

The 1.94 exact weight is only needed if you are looking for accurate spine deflection
As Jerry had stated t6he use of a 1.94 center weight was created for comparison purposes on graphite (carbon) shafts. The comparison we are talking about deals with conventional archery and comparing to Easton's Arrow Charts. Prior to Easton publishing their carbon arrow charts, they had been publishing aluminum arrow charts for many years. The standard weight used by Easton on their pro shop spine testers for many years was a 5 lb. center weight. So the 1.94 lb. weight was a change that came about with the introduction of the carbon arrow charts.

Xbow755
 

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Too complicated for me. I'll just continue buying arrows from Jerry and worry about hitting bullseyes instead of building arrows. I also buy my bait when fishing instead of spending my fishing time trying to catch bait.;):)
 

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Gabowman has a very good point. I've been building my own arrows for over 30 years because it allows me to control the critical matching and tuning steps beyond what I trust anybody else to take the painstaking time to do correctly.

That said, I know for a first hand fact that Jerry is the only arrow producer who can and will take the time to perform each of the critical steps to match spine and arrow weight if one requests it. Jerry is so selective with his shafts that I will only purchase my bare shafts from him, even when I'm building a set for competitive shooting.

Take my word for it, if he can provide the best quality shafts or arrows to meet the needs of competitive shooters, then your hunting arrow needs are a walk in the park for him.

There are no other arrow makers in this country that even come close to the quality and price of his arrows.

Xbow755
 

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I thought I'd give everybody a first hand set of details on a dozen raw arrow shafts that I just received from Jerry at Southshore Archery. I asked him to send me a dozen BEE .001 Spynal Tapp shafts. I selected the insert weights that I wanted along with the containment nocks and vanes of my choice.

Once I received his shipment I sat down at my bench and used my RAM QC Spine Tester to record the deflection range for each shaft in the group. For those of you who don't fully understand what the deflection range is, it's the stiffest and weakest reading on each shaft.

What we are looking for is to ensure that all shafts are within a similar range. This ensures that upon launch, we can expect each shaft to oscillate within a very similar frequency, therefore they should close to identical to one another. It doesn't really matter weather the numbers are in the high, low or middle of the spine stiffness range that's proper for your bow weight as long as they are all in a tight range span to one another. Any shafts that are outside of this range are likely to fly outside the other arrows. This is due to the fact that it has a different oscillation timing from the others.

Jerry's deflection range values are extremely tight. Actual values read: .134 - .137, .135 - .137, .135 - .137, .135 - .137, .135 - .137, .135 - .138, .136 - .138, .135 - .136, .134 - .136, .134 - .139, .133 - .135, .137 - .139. The higher number represents the Stiff Side Plain reading on my spine tester. That said, in order my Stiff Side readings are as follows: .137, .137, .137, .137, .137, .138, .138, .136, .136, .139, .135, .139.

Likewise when weighing his bare shafts, the weights are also extremely closely matched. Raw shafts weights in grains and in order again are as follows: 199.7, 199.5, 19.5, 199.6, 199.6, 199.6, 199.5, 199.5, 199.7, 199.3, 199.7, 199.5.

These numbers are without the addition of inserts, nocks, vanes, points or glue. Each of these additional elements add weight and will eventually bring the finished weight of these arrows up to about 434.0 grains per arrow.

The main point I'm trying to outline above is to show the readers just how closely matched Jerry's arrows are before he begins his building process. This is why he gets the applause and referral's that he does. You can spend your money elsewhere, but it's very doubtful if your going to even come close to the quality and services he supplies.

Regards,

Xbow755
 

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Jon Henry,
Very well stated! Jerry matches stiff AND weak sides. I pretty well design my own arrows, assemble them, test them, and once I have my prototype, get Jerry to make them.
We spend SO much on our hobby that the small construction expense is very minor cost-wise but very major performance-wise. This isn’t the place to skimp!
 

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Jon H... Glad you have come around to see the preciseness of the SSA touch. If your equipment wont improve its accuracy with this dozen arrows....it isnt the arrows fault....enjoy
No bare shaft tuning needed with SSA Jerrys specials..:cool:
 

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I thought I'd give everybody a first hand set of details on a dozen raw arrow shafts that I just received from Jerry at Southshore Archery. I asked him to send me a dozen BEE .001 Spynal Tapp shafts. I selected the insert weights that I wanted along with the containment nocks and vanes of my choice.

Once I received his shipment I sat down at my bench and used my RAM QC Spine Tester to record the deflection range for each shaft in the group. For those of you who don't fully understand what the deflection range is, it's the stiffest and weakest reading on each shaft.

What we are looking for is to ensure that all shafts are within a similar range. This ensures that upon launch, we can expect each shaft to oscillate within a very similar frequency, therefore they should close to identical to one another. It doesn't really matter weather the numbers are in the high, low or middle of the spine stiffness range that's proper for your bow weight as long as they are all in a tight range span to one another. Any shafts that are outside of this range are likely to fly outside the other arrows. This is due to the fact that it has a different oscillation timing from the others.

Jerry's deflection range values are extremely tight. Actual values read: .134 - .137, .135 - .137, .135 - .137, .135 - .137, .135 - .137, .135 - .138, .136 - .138, .135 - .136, .134 - .136, .134 - .139, .133 - .135, .137 - .139. The higher number represents the Stiff Side Plain reading on my spine tester. That said, in order my Stiff Side readings are as follows: .137, .137, .137, .137, .137, .138, .138, .136, .136, .139, .135, .139.

Likewise when weighing his bare shafts, the weights are also extremely closely matched. Raw shafts weights in grains and in order again are as follows: 199.7, 199.5, 19.5, 199.6, 199.6, 199.6, 199.5, 199.5, 199.7, 199.3, 199.7, 199.5.

These numbers are without the addition of inserts, nocks, vanes, points or glue. Each of these additional elements add weight and will eventually bring the finished weight of these arrows up to about 434.0 grains per arrow.

The main point I'm trying to outline above is to show the readers just how closely matched Jerry's arrows are before he begins his building process. This is why he gets the applause and referral's that he does. You can spend your money elsewhere, but it's very doubtful if your going to even come close to the quality and services he supplies.

Regards,

Xbow755

How do you have your dial indicator set up?
A lower deflection number would normally indicate a stiffer reaction. A higher number would mean more deflection or a weaker reaction.

GRIM
 

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Hi Grim,
While your statement is generally correct it actually depends on which direction your bezel dial is moving in.

When the bezal dial moves in a clockwise direction as the weight is applied to the shaft, then your looking for the lower number. When your dial is moving in a counter clockwise direction then your locking for the higher number value, since that higher number reflects less drop page of the feeler or less flexing of the shaft your measuring.

My bezal moves in a counter clockwise rotation moving through the bezal numbers from highest to lowest. I count the number of complete 360 degree rotations to record weather the spine is a 100, 200, 300 or 400 shaft and then I record the actual high and low deflection values with the highest number on the scale being the most resistant to bending.

Why my bezal moves in reverse as the weight is applied I don't know.

Regards,

Xbow755
 

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Hi Wapster,
I have been writing about and proving for years now that anyone who claims they can hold sub 10" groups at between 80 - 100 yards is full of you know what unless their arrows are both spine matched and weight balanced. That's regardless of who's crossbows they're shooting. The crossbow is only one half of the equation, with the other half being the matching of spine and weight of the arrows.

Many people will say they don't need that type of accuracy so it's not worth going thru the expense or work effort. This is where your comments from above are so important. We already spend a lot of money on our crossbows and other associated equipment. Cheating out on ones ammo is more rediculous than most people realize!

It's like buying a real expensive rifle and then trying to shoot 4 or 5 different brands of ammo at different grain bullets out of it and expecting to by accurately in the center of the target when shooting.

Xbow755
 

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Hi Grim,
While your statement is generally correct it actually depends on which direction your bezel dial is moving in.

When the bezal dial moves in a clockwise direction as the weight is applied to the shaft, then your looking for the lower number. When your dial is moving in a counter clockwise direction then your locking for the higher number value, since that higher number reflects less drop page of the feeler or less flexing of the shaft your measuring.

My bezal moves in a counter clockwise rotation moving through the bezal numbers from highest to lowest. I count the number of complete 360 degree rotations to record weather the spine is a 100, 200, 300 or 400 shaft and then I record the actual high and low deflection values with the highest number on the scale being the most resistant to bending.

Why my bezal moves in reverse as the weight is applied I don't know.

Regards,

Xbow755
LOL!!!!
I actually had to go to YouTube for a refresher course in using an analog dial indicator.
I have been using my spin indexer in conjunction with a digital scale for so long. I had to jumpstart my two remaining brain cells back into action.
LOL!!!!

GRIM
 
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