I know I read a post that covered this some time back, but I can't find it, so here it is again. I want to test an Amtak Matrix 8' 4 weight rod I'm finishing. I know it has to deflect 32", but just hold it out the tip droops a couple of inches. So, if the butt is 60" inches above the floor, and the rod was absolutely straight, I need to deflect the tip to 28" above the floor, but if the tip is already, say two inches lower, shouldn't I deflect it to 26'?

Thanks

No! Disregard the inherent sag. You need to deflect it 32" from the horizontal axis that is indicated by the leveled 12" of the butt.

Stan Grace
Helena, MT
"Our best is none too good"

Thanks Stan

Stan is correct and the reason why you would disregard the droop or sag, is because that sag is a result of the weight of the rod itself - weight the rod has to carry when you fish and cast it. Thus it is part of the overall equation.

..........

Gerry
This is a point that can cause confusion and I suspect may be a reason that some individuals vary a bit from others when measuring the same blanks or rods.
Stan

Stan Grace
Helena, MT
"Our best is none too good"

Stan, you are probably right about that. I do it just like you and Tom and since the three of us account for a good bit of the data, that's a good thing. It's nice to know if variation is due to manufacturing or people using different methods and this is one area that could cause testing variation for sure.

I did the test once yesterday and wasn't pleased with the results. I did not account for the sag at the tip and, assuming It set it up properly, the ERN came out at 2.97, barely a three. Amtak doesn't make a 3 piece 3 weight so I know it's not a matter of having gotten the wrong blank. This just seems way out of whack considering that Tom got an ERN of 4.01 on a Matrix 3 weight.

I plan to redo it again this weekend and see what I get. I'm not interested in posting bad data.

That's not way out of whack. Trust me, blanks range all over the place even in the same series. You probably did it exactly right.

As far as accuracy is concerned, shouldn't cents be added to the total count to represent the gravity deflection of the rod tip?

For example. Let's say gravity alone deflects the tip 2 inches. Weight is added to get the tip to deflect to the correct height relative to the butt. Before the ERN is looked up, shouldn't cents be added to the actual weight added to represent the defection due to gravity alone?

Or did I miss something.

Ed

Gary,

You don't want to run the CCS and then say it must be wrong because it doesn't match the manufacturer's rating. The whole reason the CCS was developed was because the manufacturers' ratings are not based on any standard. They are the subjective opinions of the maker based on how he might fish or cast the blank at some unspecified distance. the Common Cents System is objective and without bias. It can offer a measurement or reading - it does not form an opinion. It is correct by definition. If you did set it up correctly, and you very well may have, you simply have a blank that is either out of spec or something. But you can trust what the CCS is telling you just as easily as you trust the length of a board that a tape measure gives you.

The proper deflection amount was spelled out in the article in volume 6#2 and in several places over the course of the entire series on the CCS. level the first 12 inches at the butt and measure the deflection from that point. Don't worry about the tip sag - that's part of the weight the blank is carrying.

Ed,

Did you read the articles? Tip sag is part of the equation. You would only add pennies until the full deflection amount is reached. At that point the number of cents is related to the ERN. You would not add anything else. The weight of the blank affects it's performance and the CCS therefore takes that into account as well. A graphite blank, for instance, won't sag as much as a similar length and taper fiberglass blank. But they'll cast and fish a bit differently mainly due to the inherent weight difference. The CCS will reflect this in the measurements. If you add more cents to the total to overcome tip sag, you're overwriting the difference that does exists between the two.

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Edited 1 time(s). Last edit at 02/11/2005 05:23PM by Tom Kirkman.

A better understanding of this can come from thinking clearly about the physics of what is happening in a cast. For a given amount of line being cast, say the canonical 30 feet of 6 weight line, for the same accelerating force applied to the rod, we should get the same deflection of all rods of the same length that we would rate as 6 weight. What causes the deflection of the rod in a cast? Part of it is the reaction to accelerating the mass of the line and part is the reaction to accelerating the mass of the rod itself. By including the sag in the total deflection in the CC measurement, we automatically take the effect of the mass of the rod into account. What it also means is that the rod with the greater sag must be a stiffer to get the same rating.

Mike