Tailing Loops vs. Rod Action?

[VGB]

https://www.common-cents.info/

[tinpusher]

https://www.common-cents.info/

Thanks

[tinpusher]

Unfortunately it appears the database was removed.

[gordonjudd]

Is there a rod database that quantifies rod action

Doug,
Here is a link to Theo Matschewsky's rod data base for his 15 degree measurement system. http://www.solitip.de/doc/02tuning/06po ... r_hl=en-US .

His 15 degree measurement approach was discussed on the old board at http://www.sexyloops.co.uk/archivedboar ... 86#p212479. The link to his previous data base that was given in that post that was much bigger, but now gives a 404 error. You could probably contact Theo at theo@solitp.de and get a copy of his bigger Excel file.

You can use Google translator to see his site in English.

Gordy

[VGB]

Unfortunately it appears the database was removed.

There used to be one here but that seems to be broken as well

https://www.sexyloops.com/eric/database ... base.shtml

Here is a link to Theo Matschewsky's rod data base for his 15 degree measurement system. http://www.solitip.de/doc/02tuning/06po ... r_hl=en-US .

Bitdefender raised a red card on that link because of a potential security risk, maybe it's just embedded macros.

vince

[Paul Arden]

Yep I need to pull that database apart and upload it. I organised the new database just haven’t populated it. Maybe, fingers crossed, borders open in March. I can reenlist part time help again. I have tons of these things that need doing.

Cheers, Paul

[Merlin]

Here is an illustration of rod action characterization for trout rods. To plot a rod along that graph, you need to measure the dynamic characteristics of a rod. This is done by measuring speed variation with mass (rod embedded at handle level up to the “middle of the hand”), using small masses at tip top of increasing weight. Then you need to “normalize” data by reference to an 8 foot rod for a #5 line by calculation to match the scales of the graphic.

rod action graphic.JPG (32.02 KiB) Viewed 1555 times

The ordinate is the “normalized” mass in motion (equivalent mass at tip) and the abscissa is the “normalized” speed for no load.

Merlin

[gordonjudd]

Then you need to “normalize” data by reference to an 8 foot rod for a #5 line by calculation to match the scales of the graphic.

Merlin,
How do you do that normalization?

I assume it involves using the mo (mass in motion) and spring constant values you get from the frequency vs. tip load measurements and the 1/L\(^2\) dependence of the natural frequency with the clamped length of the cantilevered rod.

Where would a 9 foot rod having a clamped length of 2.711 m, k of 1.125 N/m, and mo of .0026 kg (i.e. natural frequency=3.3 Hz) fall on your curve?

Gordy

[Merlin]

Gordy

It would fall on the extreme range at right with a low ordinate (outside of the graphic). The mo value of this rod is very low for its stiffness. I use to measure frequencies with the rod clamped 8 inches from the butt end (so it would be 2.54 instead of 2.71).

Formulas are not straightforward. Here they are, the “rod length” being your “clamped length” with the 8 inches embedment.

m_0 corrected=m_0 measured* 〖((reference stiffness)/(measured stiffness))〗^0.5 〖* ((reference length)/(rod length))〗^2.5
F_0 corrected=F_0 measured* 〖((reference stiffness)/(measured stiffness))〗^0.25 〖* ((rod length)/(reference length))〗^1.25

These functions come from physics considerations. Now be careful with units used for ratios since everything must be consistent. Here are the values I am using:
Reference stiffness (#5 line) is 0.85 N/m = 0.866 g/cm = 0.0776 Oz/in
Reference length is 2.44m = 244 cm = 8 feet = 96 in.

Merlin

[Lasse Karlsson]

Hi,

I've checked Lasse's first video:

Lasse_bendy_stiff.png

There is almost no difference of the rod bend!
I'd guess: if the line weights are the same, the rods have at this configuration a similar stiffness. I don't think we're comparing here really "a bendy vs. a stiff" rod.

Greetings,
Torsten

I find it interesting how the goal posts always have to be moved

The original myth was that between a soft and a stiff rod, one had to change alot of things, timing, arc, force application etc. That would be between rods with a similar number on the side used to cast a identical line. The Berkley say 5, the sage says 6. Most would fish the berkley with a 5, and put a 7 on the Sage...So far we have had to venture far outside these parameters to have a significant difference, Paul even needs to cheat by changing the outlay of the lines before getting a difference.

Cheers
Lasse