Tom, exactly what I'm doing. Sorry my wording may be confusing, but it makes sense to me.
Pete, it sounds like you have it down pretty well and that you are careful in your procedure. All I can say is your measurements are what they are.
Norm

Thomas - Since I was all set up I grabbed the "medium" raw blank and went back out to test your theory. I never gave it a thought when I loaded the blank to test the first two times. I had not thought about that possibility and since there's no time like the present, here are my results. I found no measurable difference on this blank between IP measuring on spine and on straightest axis. In the case of this blank, straightest axis was almost exactly 90 degrees off spine. I even measured a 3rd direction with spine on belly (opposite of how I would do it for spinning rod). The finished rod (medium) that has been the other half of this topic of discussion was my 5th build and at that time I was only building on the spine, so I know that finished rod is built on spine. Other blanks may have measurable differences under these orientation specifics but this one didn't. Awesome question. Thanks for asking.

Another source of blank to blank varability of the same model may very likely be due to differences in blank sanding.
Norm

I'm using a Craftsman #39829 torpedo level. It's "newer" than most of my torpedo's so bubble view is crystal clear. It is notched on bottom which is very helpful. Norm, I'm being as careful as I can to get 100% repeatability. It's not perfect but I believe it's sufficient for what I'm trying to achieve. Appreciate the feedback again gents.

Pete,

I think you're doing fine. Any variance would appear to simply be the fact that you are measuring two different blanks, albeit of the same model.

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Norman Miller Wrote:
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> Another source of blank to blank varability of the
> same model may very likely be due to differences
> in blank sanding.
> Norm


Excellent point. Very interesting. I suspect you are referring to sanded at manufacturer. Out of curiosity Norm, have you ever checked IP of blank you might have sanded pre and post sanding?

Pete, not really. I don't sand blanks unless I am removing paint. In that situation, since I'm removing weight not blank fiber, I might acutally be increasing the IP. However, I don't really know because I haven't done a CCS analysis before and after. NFC states that sanding their unsanded blanks like the X-ray will make them softer, to me this means less powerful. So differences in factory sanding could certainly be a source of blank to blank variation, a power adjustment, so to speak.
Norm

If you sand into the power fibers, which would be the ones on the outermost portion, you would indeed reduce blank power. There's not a lot of margin for error in modern blanks so sanding beyond what the factory has done is generally not recommended.

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“Another source of blank to blank varability of the same model may very likely be due to differences in blank sanding.”

When it was time for my son to move up to a better fly rod we visited a local shop (managed by a friend) to order a #&%@ brand blank. When I picked up the blank, I became alarmed by the extremely fine tip. The same blank in a finished OEM rod in the shop wasn’t as thin. Returned to the shop with my caliper and learned the tip of the blank was two thirds of the OEM finished rod diameter. This difference was significant enough for me to request a replacement blank. The shop manager was informed by #&%@ that they would not be supplying a replacement blank.

If the over-sanding of this blank continued below the tip area there is little doubt it would have been less powerful than the OEM finished rod.

Jeff

"The greatest barrier to discovery is not ignorance, it's the illusion of knowledge" - Daniel J. Boorstin

this is why CCS will not be promoted by most big rod and blank makers, too much variation and CCS shows it..they can,t handle too many returns.

They're already dealing with that in terms of the physical weight, length and tip and butt diameters. These are all "target specs" as would be any CCS figures listed.

The reason most companies won't list CCS figures is because they not want anglers to be able to make across the board rod and blank comparisons.

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Pac Bay has given CCS on some of their blanks for years; Anglers Resource is doing it. It would be interesting to hear from both as to their experiences posting CCS. I had one blank manufacturer rep tell me once that we builders "misuse" the data. I presume that means unrealistic expectations. My experience with CCS has been very positive, with my data correlating quite well with that from the manufacturers. But I being an engineer understand variability pretty well, and all the variability I've seen has been reasonable. In fact, lower than I would expect. I know there are some who will tolerate no variation.

This has been a great string of posts. I don't think you'll find this depth of discussion on this issue on any other forum.

Michael, i,m a hobbiest and don,t build many rods in a year espacially top line blanks..is there much difference in rod variatio CCS wise or is it just low modulus low cost blanks(my kinda blank, lol.) that are the worst..i see some wild numbers sometimes but the rod still builds and fishes pretty good to me...

There is one additional component of blank making that can make or break model to model specifications and that lies in how the blank is trimmed. A 6.5 foot blank will be a tad bit longer than that on the mandrel. It is then trimmed to length. If they are all trimmed at the same points, they will be very close in overall specs. However, if one blank is trimmed an inch higher along the mandrel than another, you will wind up with a blank that is a tad bit smaller in diameter at the butt and tip, a tad less power etc. The CCS has more than enough resolution to measure even slight differences.

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If you want to be real anal about it, you have to level the center line of the blank. Leveling a tapered object will have one end of object either higher or lower than the other (depending on which side of the object you leveled) end of the object. That difference will be equal to the difference in taper from one end of the object to the other.

And precision is something a lot of us strive for when building our rods, but in the case of measurements that depend on the accuracy of the human eye, there is bound to be some variation. 10% seems like a lot, but (and I am not saying this is what's taken place) a few small, that looks goods, can add up .

Ben, most of my experience is with Rainshadow RX6 and higher, St Croix SCV, Point Blank, and a few Am Tak Bushidos and MHX's. Mostly spin/cast but also a good selection of fly. I don't see a correlation between price and variability, or lack thereof. But I have not built any really "budget" blanks. David, I "level" most blanks assuming the taper is all the same, attempting to compensate for the taper with tape on my level. . Exc for Point Blanks which are not tapered in the area where I level them. David, I think 10% is more than I've experienced on power.. The toughest measurement on my rig is AA, but even that seems to correlate quite well, and repeats within a couple degrees.

What I've noticed the most is the problem that manufacturers seem to have in rating blanks that are Xfast action, in the 80 degree AA range. Point Blank does it well, but others call some of their blanks medium light power when in fact ccs calls them a lot more powerful than that. I think they are rating the tip sections without considering that after the tip flexes, the blank is well into the powerful butt section. So what they call ML power is actually a lot more powerful.

Thanks Michael.

Is a 7' foot long blank "long" or "short?" Is a blank that weighs 2 ounces "heavy" or "light?" The CCS does not rate blanks as "fast, medium" or whatever. The whole point was to get rid of subjectively termed measurements. What the heck is "medium light power?" It's purely subjective. It was 96 degrees F here today. Is that "hot?" Somebody from the Middle East or even from Arizona might say it was "mild."

Dispense with the subjective terminology and just compare based on the numbers. You'll get the hang of it pretty quickly.

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Until we all get there crossing back and forth can bring some clarity to discussions about blanks. Right now to many people an action angle of 65 degrees means nothing. How can he get to understand what that means in terms of blank performance? If one mentions that 65 is what many crankbait rods are it's a first step in getting rid of the subjective. If someone unfamiliar with CCS has a blank that measures 80 degrees, it can be helpful to him to know that in the subjective world it would probably be called Xfast.

That can certainly work in the short term until people get a grasp of it. Ultimately, hopefully, people will get familiar with what the numbers represent without having to fall back on subjective terms.

Nobody is born with an inherent knowledge of what any unit of measurement represents (other than in a relative fashion). When you were 4 or 5 years old a term like "6-feet" meant nothing in terms of low long something was. Before long, however, you get a sense of what 6-feet means in terms of actual length. Using a measurement system enough leads to grasping what the numbers mean on their own.


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