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Problems with sweep function

KevinBH

New member
I am quite new to Pro/E and would appreciate some help. Using Wildfire 2.

My intention is to sweep a constant section along a trajectory. Problem is, when I used the Insert -> Sweep function, Pro/E asks me to select the trajectory (ok! no problems here), then to go into sketch mode to sketch out the section.

But I've already sketched out the section beforehand - and seem to be unable to just select this section and proceed. Why? Any method to do this? I don't want to have to sketch out the section again...

Next problem, if I choose to sketch after selecting the trajectory, the sketch plane is automatically normal or perpendicular to the trajectory. How can I change this to some other plane, if at all possible? Again, Pro/E doesn't seem to give me an option here??
 
The insert sweep function only allows constant section, normal to trajectory sweeps. Use the Variable section sweep (VSS)tool. It allows you to create the same constant section, normal to trajectory sweeps but also a lot more.


There's a lot of functionality in that tool, too much to try to explain here. Read up on the VSS tool in the help files to get an idea what the various options do. if you can give us some more specifics on what you're after, we can give you some helpon how to get there.


Oh, and sweeps do not allow external sketches. The reason is that the section must be tied to the trajectory intersections in order to work so you need to define the trajectories before you sketch. Also, unlike the insert -> sweep tool, the VSS tool does not allow you to sketch your trajectories, you need to define them ahead of time.
 
Kevin, whip up an example of what you are trying to do. ~Some~ of what you describe is possible, some is not and expaining it all would fill amarketable text.
 
Example:

I sketched out a 2-D airfoil cross-section on the FRONT plane. My intention is to sweep this cross-section on a straight-line trajectory - to get a 3-D wing with 35 degree wing-sweep angle.

It's a simple enough shape, and I thought the sweep function should be sufficient and need not resort to VSS.

Problem is, after selecting the trajectory, Pro/E requires me to sketch out the constant cross-section again (!) - and why should I do this, when I already have the airfoil all sketched out previously? Can't I just "select" this sketch?

Hope this gives a clearer picture of what I'm trying to do... But if there's a totally better way of doing this, please let me know. Thanks.
 
In general; depending on the type Sweep function you try to use;
look for Pivot Direction options and Select Sec options.


Don't discount the VSS because you don't think you need it.
To do what you described start the function ...
[1] Define the trajectory.
[2] Define Section plane control: Constant Normal Direction using the
sketch plane as the reference.
[3] Define X direction if necessary or desired.
[4] On the Options tab select "Constant section".
[5] Go into Sketcher and project your existing curve as a 'solid' entity
(menu: Sketch -> Edge -> Use).


That should get you.


> and why should I do this


Because that's the way the interface is written.
Know the old saw about emptying the cup ...?
 
It works! Thanks guys. VSS is the way to go
smiley1.gif
 
I don't think the use edge is going to work, if I understand right. Think about it - you're telling Pro|E that at every point along the trajectory, the sketch must be completely coincident to the previously selected curve. That's not what you want, and likely not possible.


What you want is a certain shape to follow your trajectories and then stretch and shrink with the trajectories. In that case, you want to constrain only to the trajectory intersections so that the sketch is free to 'move'. That must be done from scratch within the VSS feature.


Now, if I'm not understanding right and you want the exact section size and shape, it may work. But as you trajectory moves your section may not as you've tied it tot he position of the pre-sketched curve. If your trajectory is a straight line, it will, but then you cold have just used an extrude.
smiley17.gif



I hope that makes sense.
smiley5.gif
 
That's not what I expected, but I do understand it. You selected 'constant section' (under options), which evidently causes Pro|E to keep all the sketch geometry in the same position relative to the trajectory intersection. That's why it sweeps how it does. It does makesome sense, it's keeping the section constant (including position to the trajectory) all through the sweep.


Select 'variable section' and you get what I expected. At any given point on the trajectory, pro|E recreates the section using the edge of that original curve. The position of the original curve relative to the trajectory intersection changes as the section plane travels along the trajectory. Because you have 'constant normal direction selected, you end up with an extrude.


Ton ahve some fun and better understand the VSS tool, play with the various options and picks in the references drop down. You can do some mind bending things with a VSS.
 
Example:

I sketched out a 2-D airfoil cross-section on the FRONT plane. My intention is to sweep this cross-section on a straight-line trajectory - to get a 3-D wing with 35 degree wing-sweep angle.

It's a simple enough shape, and I thought the sweep function should be sufficient and need not resort to VSS.

Problem is, after selecting the trajectory, Pro/E requires me to sketch out the constant cross-section again (!) - and why should I do this, when I already have the airfoil all sketched out previously? Can't I just "select" this sketch?

Hope this gives a clearer picture of what I'm trying to do... But if there's a totally better way of doing this, please let me know. Thanks.


You can use the "project" tool under editing features and then click on your existing sketch. Project is similar to the "reference" tool, except it can make solid lines, closed loops, etc.
 
Use the project tool. It can be found in the "editing" tab. It's similar to the "reference" tool except it creates solid lines, closed loops, etc. Click "project" > click on the sketch you want to project.
 

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