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Accelerating a fly rod - constant or constant increasing
- Bernd
- IB3 Member Level 1
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- Joined: Sat Mar 11, 2006 10:55 pm
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Accelerating a fly rod - constant or constant increasing
Hi everyone,
when we talk about the kind of acceleration, we first have to define if this is based on
a) rod hand movement
b) line hand movement
b) movement of the butt section
c) movement of the rod tip or
d) movement of the line
In this thread I would like to keep it on the line & rod hand movement (first ).
We add force to the rod-line system.
I often read about "proper acceleration" being necessary for a good cast.
Quiet a lot of instructors add: "Start slow and end up fast".
Fine but what is proper and how do I increase velocity of my hands from slow to high?
I yet always aimed for as constant as possible.
This is for the translational part of the movement.
For the rotational part I delay my rotation.
I think the best way is to be constant in translational acceleration (moving my rod hand from A to B,
A=start position of the stroke & B= End position of the stroke).
For the rotational acceleration of my rod hand I think it should also be constant as soon as I significally start it.
No way out this can't be black or white. We probably never will reach 100% constant in truth.
What should be our theoretical ideal?
I would like to focus on translation, rotation and force application during the stroke.
For the line hand I also aim for constant acceleration as soon as I start the haul.
Maybe I am totally wrong and our theoretical ideal should be constant increasing?
Many thanks
Bernd
when we talk about the kind of acceleration, we first have to define if this is based on
a) rod hand movement
b) line hand movement
b) movement of the butt section
c) movement of the rod tip or
d) movement of the line
In this thread I would like to keep it on the line & rod hand movement (first ).
We add force to the rod-line system.
I often read about "proper acceleration" being necessary for a good cast.
Quiet a lot of instructors add: "Start slow and end up fast".
Fine but what is proper and how do I increase velocity of my hands from slow to high?
I yet always aimed for as constant as possible.
This is for the translational part of the movement.
For the rotational part I delay my rotation.
I think the best way is to be constant in translational acceleration (moving my rod hand from A to B,
A=start position of the stroke & B= End position of the stroke).
For the rotational acceleration of my rod hand I think it should also be constant as soon as I significally start it.
No way out this can't be black or white. We probably never will reach 100% constant in truth.
What should be our theoretical ideal?
I would like to focus on translation, rotation and force application during the stroke.
For the line hand I also aim for constant acceleration as soon as I start the haul.
Maybe I am totally wrong and our theoretical ideal should be constant increasing?
Many thanks
Bernd
Bernd Ziesche
www.first-cast.de
www.first-cast.de
- Paul Arden
- Fly God 2010
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- Bernd
- IB3 Member Level 1
- Posts: 2204
- Joined: Sat Mar 11, 2006 10:55 pm
- Location: Hamburg, Germany
- Contact:
Hi Paul,
in most of my experience with my students I noted that problems in loop formation mostly started when the student showed up with significant changes in the rate of acceleration. As soon as the force level was significally changed the good cast often was gone.
Again am talking about rod hand movement here.
And since we all know the angular rotation mainly makes the cast I want to keep this as constant as possible cause I think this helps me to avoid something I call "pressure points" ("sudden burst of acceleration" might be a better english term here?).
I concentrate on constant force from the beginning.
And this helps me to achieve significant smooth loops I think. :kungfo: .
But am open minded to change my point of view.
What do you aim for and why?
What are the most often seen problems that your students show up in regard of this topic?
Let me add: I often read
"constant acceleration = constant force = rod load doesn't increase"
Why would I want rod load to increase?
Greets
Bernd
in most of my experience with my students I noted that problems in loop formation mostly started when the student showed up with significant changes in the rate of acceleration. As soon as the force level was significally changed the good cast often was gone.
Again am talking about rod hand movement here.
And since we all know the angular rotation mainly makes the cast I want to keep this as constant as possible cause I think this helps me to avoid something I call "pressure points" ("sudden burst of acceleration" might be a better english term here?).
I concentrate on constant force from the beginning.
And this helps me to achieve significant smooth loops I think. :kungfo: .
But am open minded to change my point of view.
What do you aim for and why?
What are the most often seen problems that your students show up in regard of this topic?
Let me add: I often read
"constant acceleration = constant force = rod load doesn't increase"
Why would I want rod load to increase?
Greets
Bernd
Bernd Ziesche
www.first-cast.de
www.first-cast.de
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- IB3 Member Level 1
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Bernd
Not sure, are we talking about constant acceleration, or constant velocity?
W
Not sure, are we talking about constant acceleration, or constant velocity?
W
Lineslinger
Barrio Pro-team
SGAIC
AAPGAI
"The only advice it is necessary to give the angler… is to avoid any approach to foppery, as trout have the most thorough contempt for a fop…”
WC Stewart
Barrio Pro-team
SGAIC
AAPGAI
"The only advice it is necessary to give the angler… is to avoid any approach to foppery, as trout have the most thorough contempt for a fop…”
WC Stewart
- Bernd
- IB3 Member Level 1
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- Joined: Sat Mar 11, 2006 10:55 pm
- Location: Hamburg, Germany
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Hi Will,
constant velocity means no acceleration.
No cast can be done without acceleration I think.
The question is about constant or constant increasing acceleration.
Constant acceleration means acceleration with a constant rate like 10 meters per squaresecond.
Velocity would increase linear.
Constant increasing acceleration means a linear change in the rate of acceleration.
Velocity would increase exponential.
Greets
Bermd
constant velocity means no acceleration.
No cast can be done without acceleration I think.
The question is about constant or constant increasing acceleration.
Constant acceleration means acceleration with a constant rate like 10 meters per squaresecond.
Velocity would increase linear.
Constant increasing acceleration means a linear change in the rate of acceleration.
Velocity would increase exponential.
Greets
Bermd
Bernd Ziesche
www.first-cast.de
www.first-cast.de
-
- IB3 Member Level 1
- Posts: 1334
- Joined: Wed Sep 15, 2004 12:59 pm
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Just checking!
Lineslinger
Barrio Pro-team
SGAIC
AAPGAI
"The only advice it is necessary to give the angler… is to avoid any approach to foppery, as trout have the most thorough contempt for a fop…”
WC Stewart
Barrio Pro-team
SGAIC
AAPGAI
"The only advice it is necessary to give the angler… is to avoid any approach to foppery, as trout have the most thorough contempt for a fop…”
WC Stewart
- Bernd
- IB3 Member Level 1
- Posts: 2204
- Joined: Sat Mar 11, 2006 10:55 pm
- Location: Hamburg, Germany
- Contact:
Hi Tom,
does the link mean you aim for as constant as possible acceleration, too?
Greets
Bernd
p.s. That is the best article on this subject which I know of yet.
does the link mean you aim for as constant as possible acceleration, too?
Greets
Bernd
p.s. That is the best article on this subject which I know of yet.
Bernd Ziesche
www.first-cast.de
www.first-cast.de
- Bernd
- IB3 Member Level 1
- Posts: 2204
- Joined: Sat Mar 11, 2006 10:55 pm
- Location: Hamburg, Germany
- Contact:
Well, I do, too. And in order to reach an (almost) straight line path I want to achieve a smooth (constant) accelereration.
In my understanding SLP gets more difficult when aiming for a higher rate of accel. near the end of the cast.
Greets
B
In my understanding SLP gets more difficult when aiming for a higher rate of accel. near the end of the cast.
Greets
B
Bernd Ziesche
www.first-cast.de
www.first-cast.de
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- IB3 Member Level 1
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Bernd,
You might look at some of the mechanical cam curves for displacement analysis.
Particularly the Cycloid.
Very smooth with minimal energy requirements, capable of high speed without shock.
Plot butt rotational displacement vs time.
This can be coupled with a constsnt velocity portion to reduce load even further and finished with a harmonic for your stop.
The proportions should be approx 70% cycloid acceleration with a 20% constant velocity and a 10% harmonic decel.
I realize we ar not machines but we do place that title on people that are both good and consistent. In designing machinery for high speed application a great deal of care must be observed to pack maximum movement in minimum time without shock.
You might look at some of the mechanical cam curves for displacement analysis.
Particularly the Cycloid.
Very smooth with minimal energy requirements, capable of high speed without shock.
Plot butt rotational displacement vs time.
This can be coupled with a constsnt velocity portion to reduce load even further and finished with a harmonic for your stop.
The proportions should be approx 70% cycloid acceleration with a 20% constant velocity and a 10% harmonic decel.
I realize we ar not machines but we do place that title on people that are both good and consistent. In designing machinery for high speed application a great deal of care must be observed to pack maximum movement in minimum time without shock.
Eugene Moore
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