Casting Analyzer

[John Waters]

Hi Gents,

Hoping you can help. I have been using the Casting Analyzer on a distance cast and am having difficulty analysing the output. Detail is:

F.Peak: 222
B.Peak:-112
Sym 50

F.Cast:
Fwd Arc: 0
Pwr/Peak: 5.1/222
Stop/RdLd: 222/-100
Smooth ratio: 5.1
Deceleration rate: -678d/s/s
Rod Load ratio: -100%

B.Cast:
Bck. Arc: 26
Pwr/Peak: 81.7/-112
Stop/RdLd: -2/48

Back Stop: deceleration is 2144d/s/s
Rod Load Ratio: 48%

I believe this reflects some false casts but I do not understand derivation of rod load.

Thanks in anticipation,

John

[gordonjudd]

I believe this reflects some false casts but I do not understand derivation of rod load.

John,
The rod load is just the ratio of the angular velocity at the peak of the rebound hump to the value at MAV.

In reality I don't think that ratio gives you much information about the maximum deflection of the rod which would be the correct thing to measure for the loading of the rod. Even with that measurement I do not know what 100% loading would mean. 100% of what?

The angular velocity at the rebound hump is related to the factors affecting MCF and how the spring stiffness in your wrist reacts to the bending torque it produces. (Thanks to Bernd for that insight) I think that overshoot can be affected by the deceleration rate (faster stops will have more counterflex) and that correlation appears to be true in your data, assuming the real deceleration rate on your forward cast was -6780 d/s^2 not the very low value of -678 that your listed.

You might want to check that value again. A deceleration rate around -7000 d/s^2 on the forward cast would qualify as a fast stop and I expect that is what you do. A value of 2000 d/s^2 on the backcast is a relatively slow stop. A value of -=-678 d/s^2 is very slow and unless the rod was rotated out of plane I don't think you would get deceleration values that were that small.

If you rotate your wrist in your distance cast, then all bets are off on the accuracy of the CA and I would not pay attention to any of its data. When you rotate the butt about the long axis of the rod the measured velocity drops off as the cosine of the rotation angle. Thus if you rotate your wrist 90 degrees the measured angular velocity in measurement plane of the CA will go to zero.

Tom showed some measured results for that rotation effect here. One of his videos that showed the drop off in the measured velocity for different rotations is shown here.

Gordy

[Magnus]

Fwd Arc: 0

:p

Can we see the graphs John?

The CA uses one false cast. Your details look to me like the rod rotated out of plane during the stroke or some such. Basically you have a false recording for some reason.

[John Waters]

Thanks Magnus, appreciate your reply.

I am not sure how to produce the graphs.

I checked that figure, the deceleration rate was 678d/s/s. I do use a lot of wrist rotation and two planes so maybe I have generated a false recording.

I was particularly interested on recording the delivery cast so I may have to look for other methods.

Thanks again, very informative,

John

[Magnus]

Hi John

The CA uses one false cast for the Analyzer software. However the recording starts shortly after you press the button - while the rod is stationary - and usually captures 3 casting cycles - I think that's set by time not by number of cycles.
If you get the software which allows you to look at the raw data in a spreadsheet you can pick any of the cycles recorded.
If you want to look at a delivery stroke you need to deliver while the CA is recording, obviously , and to be sure that part of the recording is what you are viewing you need to open the file. The CA software can't be relied upon to show the delivery stroke.

[John Waters]

Thanks Magnus, where can I purchase the spreadsheet software? I am keen to do some comparative analysis of different distance casters' delivery strokes.
I have access to some infra red indicator, high speed photography and motion analysis software here in Melbourne as part of a study of casting technique but that requires having casters available and that is not the case in Australia. The portability of the Analyzer has attractions for my study if I can get access to acceleration data throughout the duration of a delivery cast.

Thanks again,

John

[Magnus]

Contact Noel or Bruce for the software to unlock CA files. They provided that free, I'd offer to send but mine is on a now corrupt hard-drive - which is handy.

The spreadsheet I used was MS Excel, part of MS Office.
(I guess Openoffice should do it too?)

[John Waters]

Thanks Magnus, will do.

John

[John Waters]

Shared some correspondence with Noel. Found out that Palm does talk to my MAC so that explains why a few transmission challenges presented themselves. Have loaded software onto a Windows PC and am up and running.

Thanks to Magnus, Noel and Gordon.

John