Paul Arden wrote:Of course you can compare damping in a casting situation. After all that's the purpose of good damping!
Good damping is sticking or loosing the grip when stopping.
No Paul.
In my opinion you can not do that.
As Merlin says,the speed of recovery,or the frequency will
change by the set up.
Good damping is sticking,or loosening the grip when stopping.
The best way in my opinion is to say,follow the rod,and move
your castinghand with the recovery of the rod.
Sorry for the no good Tarzan english here Paul....
Merlin, Tom, Vince,
I have no doubt Paul's test is a fine test and it tells him a lot about the casting performance of each rod. The outcome (I think) is just not based on damping.
Maybe damping has an effect, but I doubt this is possible to "measure" that way.
In regard of getting some datas to cover Paul's test results I would first of all think about ERN, AA and MOI.
Especially MOI I think should be interesting here?
Am not sure if measurng the natural frequency is very helpful here, since it changes with the line weight inside the rings, right?
Would I use Bill's method to measure it?
Thanks
Bernd
2% of the maximum peak is an industry standard but if this is too difficult to detect go for 10%.
You could either put a small mass on to represent the line in the rings or go with no mass at all. There would be a slight difference but it would be very small and as long as the test is standardised it should be sufficient.
Vince,
I once tried to measure the NF by Bill's method. What happend was, that the rod did not swing in just one plane but started to change plane all the time during swinging. So I could not really count the number of swing per unit time.
I told that to Bill, but can't remember what the solution was or if there was one to determine this. I think I remember he agreed that this happens.
I'll be honest, I haven't used his method because I would build the rod regardless and play with the tip weight to suit me. However, damping by adding a nominal tip weight may help but again it would have to be a standard weight.
Hi Bernd.
As far as I know Bill do not measure,or think that the
NF is useful?
Am I correct Bill,if you`re there?
CCF is with load,and Bill have his "feelfixer".
The swirl,or out of plane movement will allways be there.
If you couldn`t count,most likely the rod was to fast for your eyes?
And again Bernd,how did you clamp up the rod?
As you no doubt know, I have been eaten alive by the guros in another section for my views on frequency.
In the next issue of RodMaker, I have answered all these questions about how to use frequency for defining a rod. But first, we had to introduce PPF to know what one should be aiming for in the finished rod to meet a customer's expectations.
There is no guru here, maybe just a wizard. Your strong opinion is such that I have no intention to convince you about a more technical approach of frequency. You have your own and we can live with that, just regretting that a little bit of effort would bring us closer.
There is some "sweet spot" for every casting condition, some casters being just able to catch it as the conditions are changing (lengthening the line). In other words, there are many PPF. I won't try to convince you.
Merlin
Fly rods are like women, they wont´play if they're maltreated.
Charles Ritz, A Flyfisher's Life
Instead of trying to remove them, Tom, make a long carry using a Rajeff-style hard stop on the backcast to put them there, and then compare the differences between rods. I've been doing this for about 20 years. It tells you (well me anyway :p) a hell of a lot about the rod.
The difficulty you have met during the frequency measurement is wobbling, due to a bad alignement of splines of the different sections, the butt one particularly. This has been demonstrated by G Spolek some years ago.
Paul, don't you think you are trying to destabilize the rod with your test?
Merlin
Fly rods are like women, they wont´play if they're maltreated.
Charles Ritz, A Flyfisher's Life
Tom, Sakari,
I have clamped the rod at the grip section (like for the ERN measurement) and then put "some bend" to it. Grip fixed on the table and rod in the horizontal position. I let the tip go and tried to count the number of swings happening for a given time then. I can't remember the exact details, but I think I found that test on Bill's rodmaker site at that time! (Bill?)
I did not try to count by eye but simply made a video of it and then slow mo...
But the problem was the swirls.
I tried the same test with a pure blank and it did not work either. That was why I never came to that test again... yet.
The problem I have with this test anyway:
If I cast I always have different sizes of rod bend and different amounts of line weight in and outside the rings.
So what would such a single number tell me about recovery for the whole spectrum of that rod?
I agree with Paul and think his test tells me quite something. Ok, am not sure what exactly effects the results we may get with his test (obviously not only NF / damping ability). But am sure that we can sort out a rod which a high percentage of casters would feel very good about.
If you scroll down to:
"Identification of the restoring force"
you find a test which remembers me to the measurement I tried to make about the NF.
Ludwig Reim claimed to measure the speed factor of the rod and then put out a sheet telling people which rod was the fastest (recovering rod).
Fantastic. Of course all tip action rods were in the upper part of that sheet. But having a fly line to be accelerated and different rod bends will give a complete different picture in my understanding.
VGB wrote:You could do the test for a range of mass and plot the settling time. This will tell you how the damping varies across the range of use.
Vince,
I will think about it. I would like to have two rods: One having very bad damping and one having "perfect" damping. And then see if I can detect the difference with such a test and try to get a better feeling for the relationship between the test results and what I feel during casting both rods.
