With a day off today, I decided I would put numbers to some of the rods I've built. I used the Common Cents System to check the IP and AA of 7 of the rods I've built.

I set up somewhat of a jig down in my basement that would allow me to adjust each rod so that the center line of the blank would be level. I then did the computations for 1/3 of the rod's length, measured the appropriate distance down from the rod blank, and marked a level line on the bare dry wall at that point. Marking the level line not only made it easier to determine a fully loaded rod, it also made it easier to determine the AA using the diagram in the CCS article available in the library of this site.

Instead of counting pennies, I cheated and used a scale set to grams for determining the IP of the rods. If I wanted to check the lure weight range against the blank's published numbers, all it would take is some math to convert grams to pennies, and I could use the appropriate formula in the CCS for that, But I wasn't really interested in that today, Maybe at some later date. Anyhow the following are the numbers I came up with for the various blanks that the rods are built on.

Rainshadow :

Eternity2 ETES610MXF: AA 79, IP 346
Immortal IMMC73ML: AA 72 - 73 IP 605
Immortal IMMC72MH AA 75 IP 1079

North Fork Composites:

DS6107 IM AA 76 - 77 IP 387
MB 709 IM AA 69 - 70 IP 1045
MB 736 HM X ray AA 75 IP 715

Hydra:

NG SJ2 (7') AA 73 - 74 IP 554

I have to say that I was surprised by some of the numbers I came up with. Based on the published lure weight ratings for some of the blanks, as well as how the blanks feel in hand, I was expecting higher numbers for some, and lower numbers for others.

For instance, going by the lure weight ratings, and how it feels in hand, I expected the Rainshadow Eternity2 610MXF to be more powerful than the NFC DS 6107 IM. The numbers don't bare that out. Granted the difference in power of the two blanks isn't that great. It's not what I expected from the feel standpoint alone.

Another example would be the difference between the NFC MB 709 IM, and the Immortal IMMC72MH. From strictly a feel standpoint, the rods feel very close in power, and the IP numbers bear that out. But I expected the MB 709 to be higher in power because of its' lure weight rating of 3/8 - 2 oz, versus that of the IMMC72MH's lure weight rating of 3/8 - 1 oz. My expectations came from the thought that the slower action of the MB 709 would make the blank feel less powerful that it really is. The MB 709 as a listed action of moderate fast, while the IMMC72MH has a listed action of fast.

One last surprise were the numbers I came up with for the NFC MB 736 HM X ray. I built two rods on that blank, and earlier in the year I checked the IP of the other rod I built on that blank and came up with an IP if memory serves, of 658. The rod I checked earlier in the year is out in the garage in my boat. I didn't feel like going out to get it so perhaps I'll check it later. The only thing I can think of that would give that kind of discrepancy in numbers is that I may not have been as precise with my measurements then, versus now.

I leveled every single blank to make sure the rod was perfectly level before deflecting it this time. Last time I just had it set up in my old hand wrapper. Anyhow .........the numbers gave me some things to ponder, and it was fun doing.



Edited 1 time(s). Last edit at 12/03/2019 04:26PM by David Baylor.

Nice work, thanks for the report. When I find a discrepancy of more than about 5%, I recheck and usually find I screwed up on my arithmetic. I've not found blank to blank differences of more than about 5% to be pretty unusual.

ERN is a better way to list relative power and is how the inventor intended it to be used. However, the conversion is not hard to do and is shown on many CCS charts.

...............

Should have said I HAVE found blank to blank differences of more than 5% to be unusual.

Michael, I checked for the percentage of discrepancy between my measurements of the MB 736 HM X ray blanks and came up with a difference of a little over 7%. I don't know if that's within what is to be expected, but I will say that the differences in how the rods were supported probably has something to do with it. My hand wrapper has fairly thick leather laid in the V blocks, and I was using a nylon strap with Velcro ends to secure the butt of the rod. I'm thinking there was some give in that set up, that my current set up doesn't have. Anyhow, I'll bring the other rod in one of these days to check it.

Tom, I understand what you're saying. For me personally, ERN vs IP in grams is like the Metric system vs U.S. measurements. I know what one is, I have to look the other one up.

For whatever it's worth, just look at your money - it's based on the metric system. It really is that easy.

............

just think the cost of the blank is they made sure that all the fiber cuts were the same, an the glue that holds the fiber to be the same amount , , same thickness 5 % is not a bad mark as I see it

William Sidney
AK

Quite a generous use of your time, I appreciate the work. Thanks for sharing.
I'd be interested to hear about your results if you measure again that 736 XRay blank in your new setup.

_______________________________________________
If I'm not going to catch anything, then I'd rather not catch anything on flies.

Prostaff Rodhouse
[www.rodhouse.fr]



Edited 1 time(s). Last edit at 12/05/2019 03:48AM by Laurent Keiff.

Thanks for sharing David, great read.

Nick