PLEASE NOTE: This is the Archived Sexyloops Board from years 2004-2013.
Our active community is here: https://www.sexyloops.co.uk/theboard/

My first go! - What does this tell you pros?

Locked
User avatar
stesiik
IB3 Member Level 1
Posts: 2760
Joined: Tue Apr 05, 2005 12:36 pm
Location: Lapland Sweden
Contact:

Post by stesiik »

Hi Magnus!

Ehhhh, how much for the gear?

Best regards
Stefan
Dead fish don´t rise. They spawn poorly too.

Working Casting Definitions
gordonjudd
IB3 Member Level 1
Posts: 2214
Joined: Mon Jul 10, 2006 12:14 am
Location: California
Contact:

Post by gordonjudd »

What do you mean by output?The voltage from the sensor or the software?


Tom,
The voltage out of the sensor and correspondingly the analog to digital converter values that can be plotted if you have Magnus' converter routine. With that routine you can work with the "raw" analog velocity data that can be scaled to get the anglular velocity values in degrees/sec.

The analyzer measures the angular velocity for just one axis. Try turning the sensor so its measurement axis is 90 degrees to the normal orientation (measurement axis of analyzer would then be parallel with the side of the reel not the reel's rotation axis.)

Now if you rotate the rod about the reel's rotation axis you will see the output of the analyzer is near zero because you are rotating the analyzer 90 degrees to its measurement plane. Thus you will get little or no measurement values of the actual rotation velocity that was done about an axis that was orthogonal (90 degrees to) the measurement plane of the analyzer.

Most distance casters rotate their wrist in order to reach back with the rod on their backcast. That rotation will thus reduce the output of the analyzer by cos(phi) where phi is the out of plane rotation angle.

If you can keep the reel axis on a horizontal plane throughout the backcast (a good example is Grunde's style in the slow motion videos) then you will get an accurate measurement of the the actual angular velocity values.

Gordy
"Flyfishing: 200 years of tradition unencumbered by progress." Ralph Cutter
User avatar
Magnus
IB3 Member Level 1
Posts: 12097
Joined: Sat Oct 02, 2004 2:00 am
Location: Banff, Scotland
Contact:

Post by Magnus »

stesiik wrote:Hi Magnus!

Ehhhh, how much for the gear?

Best regards
Stefan
:glare:
Casting Definitions

"X-rays will prove to be a hoax."
"Radio has no future."
"Heavier than air flying machines are impossible."
Lord Kelvin
Tom
IB3 Member Level 1
Posts: 611
Joined: Fri Jan 12, 2007 5:16 pm
Location: Norway
Contact:

Post by Tom »

Tom
gordonjudd
IB3 Member Level 1
Posts: 2214
Joined: Mon Jul 10, 2006 12:14 am
Location: California
Contact:

Post by gordonjudd »

I don`t know if this will interest you Gordy,but here I am
playing around with the Analyzer:


Tom,
It is nice to find a kindred spirit that likes to take data in order to get some better insight on what is going on in casting. Your videos are very interesting.

It appears to me that you keep your casting plane pretty much in the measurement plane of the CA and thus your data should reflect the rotational velocity of the rod as you cast.

An example of someone that turns their wrist, and thus would not see the accurate data for their casting style is at Nielson #3.. You can see the rotation axis of the reel is nearly vertical at the end of his backcast, and then is nearly horizontal at the end of the forward cast. Thus his rod butt rotation changes almost 90 degrees to the measurement axis of the CA as he casts.

How did you get the real time display of the CA’s output in real time output video?

If you can, it would be nice to post a couple of more examples of the output you get when your turn the cylinder 90 degrees so the mounting bracket would be off to the left or right as you make the same rotational movements with your fingers. That would show what the CA would register if the rod was rotated on a horizontal plane with the guides on the rod pointed towards the ground.

A more relevant example would be to do your rotations when holding on to the mounting bracket instead of the cylinder. In that case you would be doing the rotation about the axis of the mounting hole on the bracket. That test will show what happens when you rotate the wrist and turn the butt of the rod so the measurement axis of the CA is misaligned with the rotation plane of the rod.

As noted before it would be interesting to see the CA’s output when it was mounted to a 90 degree elbow adaptor on the rod so that the measurement axis of the analyzer was aligned with the long axis of the rod. The integration of the resulting angular velocity values for the butt rotation about the long axis of the rod would then give you the wrist rotation phase values. Noel Perkins says the angular velocity measured by the analyzer would be reduced by the cosine of that phase angle.

If you would like it would interesting for you to post some of your loop shape examples in the gravity and the loop thread in the technical analysis forum. It appears to me that the arrow loops have little or no y change as they propagate, thus seem to defy gravity as they propagate.

What were you doing to produce the large transverse waves in wild loops?

Great data. Thanks for sharing it.

Gordy
"Flyfishing: 200 years of tradition unencumbered by progress." Ralph Cutter
Tom
IB3 Member Level 1
Posts: 611
Joined: Fri Jan 12, 2007 5:16 pm
Location: Norway
Contact:

Post by Tom »

Hi Gordy.
Thanks. :D
The real time display is the sensor hooked up with a
Pico PC Scope and the Casio camera.
The quality is poor,but I think it showes what is going on. :D
It demonstrates what the sensor is measuring.
In the wild loops clip Sven Kalmar is the caster.
I know that he is making curve casting.
We talked about it,and when filmed from the side it
does not show what is going on. :(
Please take a look at this Gordy:
http://www.youtube.com/watch?v=px78D88MEgY&feature=channel_page
Here is the sensor output:
http://picasaweb.google.no/Superra....0497314

Tom.
Tom
gordonjudd
IB3 Member Level 1
Posts: 2214
Joined: Mon Jul 10, 2006 12:14 am
Location: California
Contact:

Post by gordonjudd »

please take a look at this gordy:


tom,

thanks for doing the test of rotating the sensor out of the rods casting plane whose output shown at http://picasaweb.google.no/superra....0497314.

you can see that when the out of plane rotation is near 90 degrees the portion of the angular rotation that is measured by the ca is greatly reduced and the normal signature is severely distorted.

that shows how sensitive the output can be when you rotate your wrist.

thanks for showing some real numbers.

gordy
"Flyfishing: 200 years of tradition unencumbered by progress." Ralph Cutter
gordonjudd
IB3 Member Level 1
Posts: 2214
Joined: Mon Jul 10, 2006 12:14 am
Location: California
Contact:

Post by gordonjudd »

Tom,
In looking at your graphs once again to gauge if the angular velocity values were reduced to .707 of the real value when you rotated the butt 45 degrees it appears that the in plane measurements were clipped as shown below.
Image


Was that just an artifice of the plotting scales, or were you able to saturate the velocity sensor with a rotation rate that was beyond its measurement range? If you did saturate the sensor, what is the maximum rotation rate when that happens?

Even with the clipping it appears the maximum rotation rate registered by the sensor with the 45 degree rotation was about 69% of the values you got with the correct alignment.

Thanks,
Gordy
"Flyfishing: 200 years of tradition unencumbered by progress." Ralph Cutter
Tom
IB3 Member Level 1
Posts: 611
Joined: Fri Jan 12, 2007 5:16 pm
Location: Norway
Contact:

Post by Tom »

Sorry for not doing it properly Gordy. :(
But I think the graf and the clip illustrate your point
regarding axis-orientation.
A lot better to use a pendulum of course.
And I might do that the next time. :D
The clipping of the signal in cast 1-2 and 3,
(90deg.orientation) and mostly in the positive flank
or forward cast,is only because of the input range setting.
As far as I know,I believe they tested the sensor for rates
up to 2000deg/sec.
Personally I have not been able to saturate the sensor.
:D The linearity in this case is another thing.
I guess you have to blame me for the variation in
peak-values. :(

Cheers
Tom.
Tom
User avatar
Paul Arden
Fly God 2010
Posts: 23925
Joined: Sat Jul 26, 2003 10:35 am
Location: Travelling
Contact:

Post by Paul Arden »

How are you getting on with yours now, Stefan?
It's an exploration; bring flyrods.

Flycasting Definitions
User avatar
stesiik
IB3 Member Level 1
Posts: 2760
Joined: Tue Apr 05, 2005 12:36 pm
Location: Lapland Sweden
Contact:

Post by stesiik »

Hi Paul!

It's actually been a while since I had a go with it but I was planning on doing som comparisons with older casts soon. To find out if I managed to get the rotational speed up to your level, which was the goal this season of course. I should be closer now...

Also, I was looking forward to record Fredrik som more too.

Lets´see what I can do. I borrowed it from a friend and he might be wanting it back soon too.

Best Regards
Stefan
Dead fish don´t rise. They spawn poorly too.

Working Casting Definitions
User avatar
Paul Arden
Fly God 2010
Posts: 23925
Joined: Sat Jul 26, 2003 10:35 am
Location: Travelling
Contact:

Post by Paul Arden »

I don't think Fredrik needs any more practise.
It's an exploration; bring flyrods.

Flycasting Definitions
User avatar
stesiik
IB3 Member Level 1
Posts: 2760
Joined: Tue Apr 05, 2005 12:36 pm
Location: Lapland Sweden
Contact:

Post by stesiik »

Hi Paul!

I dissagree! He needs to learn how to hit it with much more power much earlier!! I am trying to get him over to the rotation only cast aswell, as taught by Frank!

There will be a shootout here next year too... :p

Best regards
Stefan
Dead fish don´t rise. They spawn poorly too.

Working Casting Definitions
fredrikh
IB3 Member Level 1
Posts: 120
Joined: Sun Nov 02, 2008 3:14 pm
Location: North Sweden
Contact:

Post by fredrikh »

stesiik wrote:I dissagree! He needs to learn how to hit it with much more power much earlier!! I am trying to get him over to the rotation only cast aswell, as taught by Frank!

Working on that.

I have got a topsecret instruction video. :p
User avatar
stesiik
IB3 Member Level 1
Posts: 2760
Joined: Tue Apr 05, 2005 12:36 pm
Location: Lapland Sweden
Contact:

Post by stesiik »

Hi Fredrik!

I see Paul allready showed you the ropes. Yepp, mimik that to get further! :p

Here is another great tip from Jon Allen:

http://www.sexyloops.com/movies/jonallen.shtml

BTW, do you and your brother have time for a session this weekend? Doc is on too I'm sure. He is carrying over a meter more line now... (where will this end... :oh: )

Best regards
Stefan
Dead fish don´t rise. They spawn poorly too.

Working Casting Definitions
Locked

Who is online

Users browsing this forum: No registered users and 1 guest