I am a new rod builder having built only 3 rod from kits. I noticed reference to ern and aa . dont want to be stupid but what are they and how do you arrive at same?

They are used to measure power and action. The ERN is effective rod number and the higher the number the more powerful the rod. The AA is the action angle and is the degrees read off the tip of the rod when presented against a protrator and the rod flexed to a predetermined amount. The higher the number in degrees the more tip oriented the blank flex is. You can read the about the system in Rodmaker. I think the series started in the Volume 6 issue number 2 copy. I've found the system very helpful when comparing blanks and wondering which one had more or less power and was more or less tip flex oriented.

Bill,
If you are going to build more rods you really want to become familiar with the Common Sense System. As Danny points out it will allow you to accurately quantify both the power and the action of a rod/blank rather than just using the old medium, fast, estra fast or light, medium and heavy designations that the rod manufacturers use.
The system is probably a bit much to try to describe to you here but it is described in detail in past issues of RodMaker and Tom has also put together a 4 or 5 page version that is available on the RodMaker site for a nominal fee.

Or come to Charlotte for the big show and learn about it from the inventor!

Bill

My advice:

Read, re-read and re-read.....then read it again. This, to me, was one of those things that I just had to steep myself in by re-reading everything several times before the light came on. Once there, it makes perfect sense (or cents as the case my be)

Thanks for the responses. will look the articles up.