DynaRod was developed as a rod design tool which mainly works based
on rod deflection and rod action. Basic idea is to decide a rod taper through
designing its deflection and action.
Another consideration in the development project was how to make
it easier for a rod user (fly fisher) and a rod maker to communicate and agree
with on a rod requirements to each other. For instance, both of user and maker
could clarify the requirements on a rod by looking at the screens of
DynaRod.
DynaRod also challenges to the implementation of the definition of
rod action by referring to new words, Rod Angle and Tip Top Tangent Angle. This
challenges to the existing definitions for Fast, Medium and Slow rod action.
Characteristics of DynaRod
Calculating dynamics
DynaRod performs the calculation of a rod deflection dynamically as
its name implies. For a question "Is there a dynamic type calculation for a
static rod model, which means that the rod is not moving?", the answer is YES.
To understand this clearly, let's consider a rod which is fixed to the wall at its grip
and the rod hangs a certain weight at the tip top. The rod will start bending
from the tip top and balance at a certain level with flexure. DynaRod performs the
calculation of the bend angles of this rod dynamically. "To calculate
dynamically" means that the shape of the rod "one second after" is
calculated based on the shape of the rod "one second before". This type of
calculations are continued until the rod finally balances.
For a dynamic rod model, the dynamic calculation must assume that
the rod is moving. That is, when a rod moves in a certain duration of time,
for a certain distance and towards a certain direction, DynaRod calculates the receiving
load on the rod, and calculates the deflection and stress as the result of rod
movement, dynamically from time to time. At this time, it also calculates the
values for "one moment after" based on the "one moment before"
situation.
Then how does DynaRod assume and understand the rod movement?
Users of this tool can define or design the movement of a rod by using one of DynaRod
features. It is called as "definition of casting", or "design of
casting style". If a casting style is defined, rod movement can be
automatically calculated for direction, time duration, and velocity, as a result,
acceleration and so on.
In dynamic calculation, it divides a duration of time (mostly the
unit of second) into several continuous subdivided time blocks, called as
"phase". Within one block of time, calculation is made based on the rod
details which was resulted in the previous time block and this is repeated for all
the subdivision of time. So it spends a little time to complete the calculations for
one casting style, then the resulted deflections and stress curves become very close to
natural and actual rod deflection as if the rod is cast in actual fishing scene.
Table Driven Calculations
DynaRod performs calculation in various aspects based on the table
records which are entered by a user. And the calculation panels also have additional
capability of changing the assumption of calculation.
It does not perform the same calculation always, but
performs the different calculation according to the changed assumptions via tables and via
an input panel, as a user desired.
One typical example of table, user can specify a new bamboo specie
which is to be used for a rod. Once Bamboo Attribute Table is set with new entry of
bamboo specie, user can select the specie when entering or modifying rod specification via
input panel. The rod with that specie has different MOE (Modulus of Elasticity) or
Weight per cubic inch. DynaRod will use those specific attributes for the rod
through Bamboo Attribute Table when performing calculation.
Even if the original Bamboo for a rod is recorded as Tonkin, user
can change the bamboo on calculation panel when one would like to simulate another
specie.
There are several tables such as Bamboo Attributes, Line Weight,
Ferrule, Top Guide, Snake and Stripping Guide, Typical Grip and Reel Seat Arrangement, and
Reel Weight. These all are user definable tables.
Though DynaRod is basically designed for designing Fly rod, Lure rod and Boat rod can also
be designed by defining necessary guide sets into the following tables.
- Guide Attributes table
- Top Guide Attributes table
- Users Guide Size Default table
Please refer to Table Setting Menu and each Table panel for further
details.
Dual unit capability of Metric and Pond/Yard measure
DynaRod maintains data in ounce/inch unit internally. Most of
screens and PF Setting output have a capability to change the unit of data by pressing
[toggle Unit] buttons. As for Graph data, unit is mostly in inch, ounce and
yard. Since most of data are dealt in inch in rod making, user may not feel any
inconvenience.
Difference from Garrison style Stress Curve
The stress curve based on Garrison's mathematics has long been the
tool for designing a rod for rod makers. But it is also true that there are
following critiques;
By those effects, stress curve of DynaRod gives up to be the
objective of rod design but becomes a practical stress distribution curve under a certain
load. We can identify how stress is distributed over a rod, practically on the
dynamic stress curve.
Establishing a new design criteria
Design approach via static stress curve are often used to convert an
existing taper rather than designing a completely new rod taper from scratch. For
instance, we often want to convert two pieces rod to three pieces and vice versa, or want
to change the taper from for #4 weight line to for #5 weight, etc.. As dynamic
calculation changed the positioning of stress curve from a design criteria to stress
distribution graph, a new rod design criteria must be considered, especially in the
dynamic calculation.
DynaRod established a new design criteria by "rod
deflection" and " action genome". Genome is a pattern how a rod
would act in deflection. It implies that by taking one of the action patterns, we
can inherit the similar deflection to a new rod. Rod action is really like a genome.
Definition of rod deflection and action genome
Rod Deflection is an overall shape of flexure and the depth of bend
form.
Action Genome is patterns of rod bending through a rod. Action
genome has a similar tendency to Garrison's original stress curve, and maintain the
physical relationship with rod deflection always. This nature of action genome makes
rod deflection to be a practical design criteria.
The physical relationship between rod deflection and action genome
can be seen in the Deflection Designer tool, which is invoked by the function [Design by
deflection]. It is an Excel tool and packaged in DynaRod As it also works
standalone, it can be used as a study material of rod deflection and action genome.
I hope that the usage of the tool would extend the understanding what stress curve means
since both are very similar.
DynaRod made it possible to design a rod (taper) from scratch, that
is, to produce a new rod (taper) which has not existed. There are various types of
rod tapers remained unknown yet.
About the System
DynaRod is developed on the technology of Microsoft Access,
Visual Basic for Application (VBA) and Excel. Database of Access, processing by
VBA and graphic capability of Excel are functionally integrated. Users can use its
functions by communicating with DynaRod via Access screens.
Output of a rod from DynaRod is written into several excel files,
one excel file per a function button. Even after closing DynaRod, user can look into
the output excel files standalone. DynaRod did not develop its own print
functions since Excel has flexible capabilities to produce print out hard copies and to
make further calculations via its macro.
Components of DynaRod Package
Download package of DynaRod contains the following
components;
Do not erase any of components from the folder. All the components should reside in
the same folder.