Pro/E WF 2.0: Datum Curves

[anup.more]

Hi



Can anyone explain me the behavior of datum curves when I change
different parameter values (for e.g.: a helix using cylindrical equation
form.). I'm not able to understand the changes in pattern of curve
formed when I arbitrarily change any of the values in the equation.



Please explain anybody...?







Thanking You,

Anup More

Engineer- CAD, PED

Emerson Climate Technologies (India) Limited


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[ptc-1932745]

No problem, can you show us the equation that you are changing?



In a cylindrical co-ord system the parameters are in relation to
R(radius) and theta(angle), vs. X and Y.



Other than that the changes should be straightforward.







Christopher Gosnell

TRIGON INC.
FPD Company
124 Hidden Valley Road
McMurray, PA 15317
PH: 724.941.5540
FX: 724.941.8322
www.fpdinc.com

[anup.more]

Hi



Can anyone explain me the behavior of datum curves when I change
different parameter values (for e.g.: a helix using cylindrical equation
form.). I'm not able to understand the changes in pattern of curve
formed when I arbitrarily change any of the values in the equation.



Please explain anybody...?







Thanking You,

Anup More

Engineer- CAD, PED

Emerson Climate Technologies (India) Limited

[anup.more]

Hi



Can anyone explain me the behavior of datum curves when I change
different parameter values (for e.g.: a helix using cylindrical equation
form.). I'm not able to understand the changes in pattern of curve
formed when I arbitrarily change any of the values in the equation.



Please explain anybody...?





______________

Anup More

Engineer, CAE PED| Emerson Climate Technologies (India) Limited,
Karad-Dhebewadi Road, Karad-415110
Off: +91-2164-241413 (2126)| Mob: +91-9767899779 |
anup.more@emerson.com <">mailto:sundeep.kamal@wipro.com>

[JonathanHodgson]

Anup,

You've posted this three times now (unless it's your email system
playing up, in which case I apologise).

You've already had one answer in which you were asked for the particular
equation - without this it's impossible to understand and answer your
question.

Regards,
Jonathan

[dgraham-4]

Anup,

How about send us your equations? That said, for a helix

r = radius of helix
if you want a conical helix with r varying from 2 to 4 you have to write:
r = 2+(2*t)
why you ask

Here's the deal. First you need to understand that t (aka trjpar, aka
trajectory parameter) varies linearly from 0 at the beginning of the curve
to 1 at the end of the curve.
Therefore at the beginning of the curve
r= 2+(2*0) which equals 2
in the middle of the curve
r = 2+ (2*0.5) which equals 3
at the end of the curve
r = 2+ (2*1) which equals 4

z = the height of the helix
if you want a helix 10 unit in height
z =10*t
why you ask
well, z is actually the distance from your select csys.
If you want the starting point to be in plane with the csys and end 10
units away z must equal 0 initially and 10 finally.
At the start of the curve
z=10*0 = 0
At the end of the curve
z=10*1 =10

theta is used to drive the number of coils in your helix by setting how
many degrees the helix winds through out the length of the curve
theta = 360*t*4 yield four revolution
why you ask
at the start of the curve
theta = 360 *0*4 = 0 degrees of twist
in the middle of the curve
theta = 360 * 0.5 * 4 = 720 degrees of twist
at the end of the curve
theta = 360 * 1 * 4 = 1480 degrees of twist or 4 full rotations

Hope this helps

David

[TracyWillis]

Anup
Is this the information you seek?

r =
/*example: r = 3
/* r means Radius.
/* It is the radius from the coordinate system you select.
/* It can be a Parameter driven value & in which case r = YOUR_CHOSEN_PARAMETER_NAME
/*
theta =
/* example: theta = t * 360 * 4
/* t is 360 degrees times the number of Revolutions in the helix curve (can be a decimal & create a partial loop...3.250 rev's)
/* 3.25 would yield 3 complete loops, last loop would be 1/4 complete and the curve would end 1/4 way past the plane of the helix start point.
/*
z =
/* example: z = 10 * t
/* 10 is the distance from the curve start point to curve end point.
/* You can control the direction of the curve and flip it by changing this to a negative number.
/* This value will change the pitch spacing of the curve loops.
/* It changes the pitch because the number of REV's and the Radius are set by the above settings for theta and for r

Good Luck hope this helps.

Have a wonderful weekend everyone.

Tracy Willis
Designer / Drafter

Cook Urological, Inc.
11OO West Morgan Street
Spencer, IN 47460
(812) 829-4891
(812) 829-1801 (fax)

Confidentiality Note: The information contained in this e-mail is strictly confidential and privileged information which is intended for the use of the above addressee(s) only. All other use is strictly prohibited. If you are not the intended recipient, any review, distribution or copying of this document is strictly prohibited. If you have received this e-mail in error, please notify the sender immediately and delete the document from all computer systems, or notify Cook Urological at (812) 829-4891.

[anup.more]

Hi,



Thank you david & tracy, your information was very much useful to me as
I'm new to this datum curves command.





Jonathan, this is for e.g. an equation for reference. This equation
creates a spiral curve at z=0 (in xy plane).

r= t*10

theta= IR*t*360*5

IR=5

z=0



I was just checking the equation by arbitrarily changing the values.



One thing I tried was referring IR with (t) which gave me a variable
spiral curve. Like changing the equation to IR= t*5 & keeping rest of
equations untouched.

Plus, when I refer z with (t) for e.g. z= t*1, then the curve I get is a
conical variable helix curve!



Basically, the important factor I need to understand in datum curves is
the trajectory parameter. So, david, what if I need to vary the radius
from 2 to 13, what would be my equation then?



Thank You for your answers.



Regards,

Anup More

Engineer- CAD

Emerson Climate Technologies (India) Limited

[ptc-1932745]

Just my $.02...



t is a parameter that goes from 0 to 1 uniformly throughout the
equation.



To make R go from 2 through 13 you need to come up with an equation
relating R to t*(delta R)+ a constant



First R does not start at zero, so at T=0, R=2

Secondly, at T=1, R=13 (R increases by 11)



So the equation looks something like this:



r=(t*11)+2







Christopher Gosnell

TRIGON INC.
FPD Company
124 Hidden Valley Road
McMurray, PA 15317
PH: 724.941.5540
FX: 724.941.8322
www.fpdinc.com