A/C/E question

[Focal]

I have noticed that people selling A/C/E's will not the series, C-3, C-4, C-5, etc. What is the difference, and how can you easily tell? Is it marked on the arrow?

[Robert de Bondt]

I have noticed that people selling A/C/E's will not the series, C-3, C-4, C-5, etc. What is the difference, and how can you easily tell? Is it marked on the arrow?


C is the weight category code and is printed on the arrow under the Series Code 1206G. Weight uniformity from shaft-to-shaft in a set is necessary for good grouping. The most inconsistent part of a carbon/Al. arrow is the weight of the resin. Therefore, ACEs are usually sold by the dozen in the same weight category.

Others might be able to tell you the number of grains difference between the various groups.

[Focal]

so no set is better than another, just so long as you keep them all in the same weight class?

[Robert de Bondt]

so no set is better than another, just so long as you keep them all in the same weight class?

That's about right. ACE shafts are selected in sets of 12. The weight tolerance is + or -1.5 grains (0.1 grams) and Spine tolerance is + or -0.005" (0.13mm) and straightness tolerance is + or - 0.002" (0.06mm).

An interesting point is that spine standards are set at 75deg.F (24degC)
When testing it is recommended not to hold the shaft to be tested in the middle, but by both hands, as the prolonged contact with the hands will heat the shaft causing greater deflections than normal.

My question would be and may be Jim Park or someone else can answer this, how much difference would there be in spine deflection of the same arrow if shot by Harald in Norway at 0degC or in Athen's 45deg C summer heat? Would the difference be significant enough to worry about under these varying conditions.

[grantwomack]

That also raises another point of the size of arrows changing with the heat they are being shot in. 9.3mm is the maximum allowed diameter of arrows. 2315's are usually used because they fall within this allowance. 2316's can as well, so long as they are made to very high tolerances. But if you are shooting in very cold weather, would the size of a 2316 be allowed, even if it wasn't made to such high tolerances?

[Flehrad]

If it's cold weather, wouldn't the alum shrink and be less than the restriction?
Surely you mean hot weather, where it might expand?...

[grantwomack]

If it's cold weather, wouldn't the alum shrink and be less than the restriction?
Yes, that's what I was saying, wasn't it...? :-?
Just re-read. It should have said something like "If it was cold weather, would 2316's that were made to lower tolerances (possibly slightly larger than actually 2316) be allowed since they would shrink that little bit?"
Does that make it any clearer? Difficult to word, I think... :-?

[gt]

An interesting point is that spine standards are set at 75deg.F (24degC)
When testing it is recommended not to hold the shaft to be tested in the middle, but by both hands, as the prolonged contact with the hands will heat the shaft causing greater deflections than normal.


Where DO you people get this stuff ? The resin system used in Easton AC shafts has a Tg well over 200F.

The reason for the temperature standard is so that the spine TESTER doesn't have to be made from Invar or other low CTE alloys. If the test device length were to change by a small amount due to temperature, it would throw the readings off by quite a lot- support span is a third order function.

[clever_guy]

GT!?!? Posting on AF?? Did you get lost surfing the web??

;) :lol: :lol: :P

I am just going to check out my winter wardrobe inc ase hell's tempeture starts to plunge unexpectedly...

;) :lol: :lol:

-CG

[Robert de Bondt]

An interesting point is that spine standards are set at 75deg.F (24degC)
When testing it is recommended not to hold the shaft to be tested in the middle, but by both hands, as the prolonged contact with the hands will heat the shaft causing greater deflections than normal.


Where DO you people get this stuff ? The resin system used in Easton AC shafts has a Tg well over 200F.

The reason for the temperature standard is so that the spine TESTER doesn't have to be made from Invar or other low CTE alloys. If the test device length were to change by a small amount due to temperature, it would throw the readings off by quite a lot- support span is a third order function.

All this information came from Easton Technical Bulletin Number 13, October 1990 "Easton Pro Shop Spine Tester". The info may be a bit dated, but is a 1990 ACE a different construction and resin than the 2004 ACE?

[recurve boy]

Where DO you people get this stuff ?

All this information came from Easton Technical Bulletin Number 13, October 1990 "Easton Pro Shop Spine Tester". The info may be a bit dated, but is a 1990 ACE a different construction and resin than the 2004 ACE?

I suppose the answer to GTs question then, would be GT! :lol:

[Robert de Bondt]

An interesting point is that spine standards are set at 75deg.F (24degC)
When testing it is recommended not to hold the shaft to be tested in the middle, but by both hands, as the prolonged contact with the hands will heat the shaft causing greater deflections than normal.


Where DO you people get this stuff ? The resin system used in Easton AC shafts has a Tg well over 200F.

The reason for the temperature standard is so that the spine TESTER doesn't have to be made from Invar or other low CTE alloys. If the test device length were to change by a small amount due to temperature, it would throw the readings off by quite a lot- support span is a third order function.

George,

I might not have phrased my question properly. I know and appreciate that most engineering tests are done under controlled environmental conditions, for reasons that you stated. The interesting thing for me was the statement not to hold the shaft in the middle, as prolonged contact with the shaft would cause greater deflections than normal.

If that is the case, I feel my question was quite valid to ask that if prolonged contact with the shaft in the middle would result in a greater deflection, what would the effect be on the deflection if one would test a shaft at say 40degF compared to testing a shaft at 90degF. Maybe SFA, but then again Easton might have done tests like this and I personally would be very interested to know if there would be any significant variation. I am sure so would a lot of other archers on this forum and elsewhere.

Below is an extract
Easton Technical Bulletin Number 13, October 1990

FOR MORE ACCURATE TESTING, PLEASE NOTE THE FOLLOWING:
1. Spine standards are set at normal room temperature, 75

[DrRalph]

Sounds like a fair question to me, nice one Robert.

I admit it is surprising, however, given the thermal properties of the shaft materials.

Maybe some people have *reall* hot hands.

[gt]

The text relates to the highly precise and rather delicate MASTER SHAFTS used for calibration of the tester. That is the context of those instructions, which has nothing to do with ordinary arrow shafts. Handling of master shafts was to be kept to a minimum for a variety of reasons.

There is far more effect from temperature on the characteristics of the average bow than anything one might see on an arrow shaft.

No Easton shaft has any significant spine change within temperature ranges in which archery equipment could possibly see use (-40 to +50 degrees C), and AC shafts in particular are immune from temperature related changes well past that range.

Amazing the things some people worry about.

[Robert de Bondt]

Amazing the things some people worry about.

George,

Thank you very much for your informative reply.

I don't think it is a matter of worrying about things like that, but more an intellectual interest in all aspects of archery and archery equipment.

I don't really appreciate your condescending attitude to us mere mortals, but respect you for your knowledge and experience. It would be nice if we could share more of that, but without the sarcasm.

Have a nice day.
Robert