Missing edges in drafting? 1

[Wittenborn]

Hi all,

I have been searching through the posts on this topic, and haven't found exactly what I am looking for.

Here is my problem:

I have multiple parts (an airplane) in an assembly, all of which are surfaces (sheets). I have brought the assembly into drafting, and I am looking at a side view. I noticed that many of the edges are not drawn correctly, and some are even missing.

I have played with the tolerance value in the "General" tab of the "Style" menu, to no avail. If I manually make the tolerance zero, the drawing updates, but the tolerance value then gets set to 0.0263.

The higher I make the tolerance, the more of my edges show up correctly, but then others appear that don't look to be trimmed correctly. Playing with the Smooth Edges settings doesn't help substantially.

Could someone offer some advice to how to manipulate a view in drafting such that all of the edges show up correctly without jacking the tolerance up so high that you are left with straight lines representing curves?

For now, I have a setting that looks OK, but I will have to do a view-dependent edit to get rid of all the misfit curves.

Any suggestions?

Regards,
Grant
Aerospace Engineer

 

[Xwheelguy]

Without actually seeing your part, it's hard to say. Are the 'misfit' curves actually skewed when viewing from that angle? Are you trying to accomplish a section view just by using an orthographic view? Do you have silhouettes turned on? Do you have hidden lines visible? Do you have UV Grid on? Have you turned any of these off/on to see if that fixes your problem?

Look at EACH setting in View Preferences & turn each one on/off to see if it helps any at all. I wish I could be more specific, but without a part in front of me & without knowing what you're trying to accomplish, it's hard to pinpoint a specific solution.

Just to be sure, you are aware that smooth edges only deals with tangent edges, corrent? What this does is turn off and on the display of tangent edges of the model in drafting views.

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

 

[Wittenborn]

Thanks wheelguy,

I have been playing with all of those settings, in particular the silhouettes.

What I am seeing is that the view is extremely dependent on the tolerance setting. I can bump up the tolerance and get 99% of the curves to appear, but then I am left with a bunch of curves that I don't need (which I can delete with a view dependent edit). For instance, I am looking at the front view of the airplane, and am seeing curves from the aft surface of the fuselage (with a high tolerance setting). With a smaller tolerance, I don't see these lines, but I also don't see many of the lines that would be visible from the front view.





Regards,
Grant
Aerospace Engineer

 

[Xwheelguy]

It might be the fact that you're using surfaces as opposed to solids. I'm not sure though because I always work with solids. I've never noticed the tolerance settings having such adverse effects as to make curves appear & disappear though.

Should the curves that appear on the aft surface of the fuselage be hidden? If so, you need to set hidden lines to invisible. Are your surfaces modeled with a very loose tolerance?

I'd recommend calling GTAC (800-955-0000) and discussing this with them. They may ask for your data so they can get a better idea of what you're trying to accomplish.

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

 

[Wittenborn]

Thanks Tim,

I'll give them a call. I do have the hidden lines set to invisible, which is why this is so puzzling.



Regards,
Grant
Aerospace Engineer

 

[ewh]

Are you only working with sheet bodies or do you have some edge curves in your model?

 

[Wittenborn]

I am only working with sheet bodies.

I have noticed that if ALL surfaces are not trimmed to each other, UG will have a hard time picking up on the intersections. So that was part of the problem, but I am still finding a few missing curves.

Regards,
Grant
Aerospace Engineer

 

[Xwheelguy]

Grant,

How goes the edge display in drafting?

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

 

[Wittenborn]

Well, I accomplished what I needed to accomplish, but it wasn't as seamless as I would have hoped.

I ended having find a tolerance that displayed a majority of the required lines, and then edit out the edge lines I didn't want.

Basically, I got the drawings I needed, but am still not happy with the method in which I did them. I suppose that the complexity of the assembly has something to do with it, but I figured UG would be smart enough to figure out which lines might be showing and which ones won't.

If anyone has any advice, I'm all ears!

Regards,
Grant
Aerospace Engineer

 

[Xwheelguy]

I'm guessing that it's because there are surfaces involved versus complete solids.

If it's something you feel UG should be doing, log it in with GTAC as an IR & at the same time request enhancement for the IR.

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

 

[Wittenborn]

One of the things I just thought of which might cause a problem:

Many of my parts are based on other parts geometry. For instance, the wind shield on the airplane. I have created a sketch, projected my curves on to the fuselage surface, and then trimmed out the windscreen.

Then, in another part, I bring in the fuselage surfaces (prior to the trim timestamp) and then trim the surfaces again to the same sketch profile, but this time keeping the windscreen part.

So what you actually have is two parts (the fuselage and windscreen) sharing the same edges, but by virtue of how they were created, some of the edges may share tangency by virtue of being created from the same surfaces...

Make any sense?

Maybe it's not UG that's the dumb one here?

Regards,
Grant
Aerospace Engineer

 

[Xwheelguy]

Well, yes, if you're using the exact same trimming curves on 2 different bodies, the edges are going to lie on top of one another & you should only see one outline in drafting. Why even create an assembly? Why not just subdivide faces of the fuselage?

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

 

[Wittenborn]

But that's the problem, I'm not seeing an outline at all. I am seeing three sides of the windshield, but not the fourth.

The idea behind creating a windshield part and a fuselage part was that down the line, we are going to want to build structure around the window (mounting flanges, etc) and I didn't want to do that inside the fuselage part. I guess I am thinking from an organizational point of view, it is easier to work on two separate parts.

In the mean time, I might try your suggestion of sub-dividing surfaces.



Regards,
Grant
Aerospace Engineer

 

[Xwheelguy]

Hmmmmm....on very rare occasions I've seen similar occurances. It only happened on drawings with assemblies though.

It might just be that the edge is too skewed to be shown correctly.

There's another setting in the view style menu....edges hidden by own solid....make sure that is on & play with your tolerances. See if that helps. I'm really at a loss with this one.

Your earilier posts were a bit difficult for me to visualize. The windshield was much more helpful. It can be quite difficult to explain a problem or solution at times. I appreiciate your patience.

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

 

[Wittenborn]

Thanks for YOUR patience, Tim.

I played with the files a little bit yesterday and found that each individual part shows up perfect, but put them all in the assembly, and you end up with missing edges.

If I get a chance today, I'll give GTAC a call.

I'll post here if I get anywhere with them.

Thanks!

Grant