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Variable section sweep...need help

V

Vivek B

New member
Hi,


I ws trying this VSS in WF4 with an origin curve at the centre and 4 curves surrounding it at 90 degrees apart(identical opposite curves). When I try to make the sweep with the centre straight line as origin and the rest as the trajectories...it takes only one curve profile and ignores the rest...i.ethe result is similar to that of a revolved one....
smiley19.gif
.I am not able to get the profile generated by the combination of these curves...and I am pretty confused with this X-traj, Normal Traj etc..


Can someone explain this to me?...if u could explainthe steps what I should do..that would b great...
 
does your sketch connect to all of the 4 curves? do you use any kind of "referenses" (iow "use edge" ) in your sketch?


if possible, post a pic, its much easier to help!!


//Tobias
 
Do you have a trajectory at the center?

What is your section? Is it a circle? If so, it won't work if I understand your trajectories right.

It looks like opposite trajectories are mirrored, right? it also looks like you have a circular section with the center of the circle constrained to the center via two datums or a center trajectory. Then you try to tie the circle to the 4 trajectories. With the center locked, however, only 1 trajectory can define the radius, so Pro|E is ignoring the others. I wish this sort of thing would fail, because what you are telling Pro|E to do is geometrically impossible.

I think what you will need is a sketch with 4 conic arcs, each end of each arc tied to a trajectory. Also, each end should be constrained or dimensioned as normal to the plane that trajectory is sketched on. That will allow it to stretch to meet each trajectory.
 
Some definitions:

X-trajectory - This controls the orientation of the sketch. A line that passes through the origin trajectory and the X-trajectory will be the X-axis in the sketch

Normal Trajectory - A the sketch travels through the sweep, it will remain normal to this trajectory.
 
A circle wont work because a circle i a "perfect round geomteric shape"
smiley2.gif
, and in this case, the shape of the sweep will not be "circular" along the trajetory. So, just like DGS says, "it is geometrically impossible."



If the 4 curves woud have looked the same , all the way, then it would work. But on the other hand...then you dont need 4 curves, just 1...


please specify your questions about norm to trj, x-vector and so on. I bet i could talk atleast 5 hours on Vss....it
 
dgs said:
Do you have a trajectory at the center?

I think what you will need is a sketch with 4 conic arcs, each end of each arc tied to a trajectory. Also, each end should be constrained or dimensioned as normal to the plane that trajectory is sketched on. That will allow it to stretch to meet each trajectory.
Click to expand...

It should also work with a spline or an ellipse defined as center/2 axis, don't remember if it's available only in WF5...

Paolo
 
Hi all,


First of all thanks for the help...I appraciate your time...


As Tobias & Doug said circle is a perfect geometry...but ellipse can do the trick bcuz the major & minor axis can vary accordingly...so it was working and as Sanjeev said it shouldobviously work with spline...bcuz ther is no such geometric constraints....anyways I got it through guys


Once again thanks..
 
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