creating a web

[Crompton]

Hi all

Anybody answer what in Autocad is a simple operation.
I want to create a web (sorry if this not what you call it)

In autocad i would construct a triangle by clicking on the ends of the construction lines and extrude it.

Ok i make the construction lines where I want the web to go.
I create sketch on back face of two lines
then create sketch at top face and project geometery to it.

I can then create a work plane from the ends of the lines at the top face (left side) to the ends of the lines at the back face (right side) but how do i get the sloping line to attach to the lines that are now not on the work plane.
I can guessimate them they are there somewhere. But it not right.

How do you snap to any point that crosses terminates or starts on your workface?

Ok when i know how to do this I can extrude the web.

now I have 1 web i want to copy them to the other 3 positions.
I know I can rectangular array them but i aint got that far yet.
I want to copy/paste.

I click on part I need to copy RMB copy
RMB paste dialog box opens, i then select the face i want to attach the copied part to but the part attaches at an seemingly random point to the selected face. (I know it is not random but in Autocad you copy with base point select part, select a point to use as base then click paste and the base point goes there.)

so how do i select the face or point i want to use to attach to a point or face?


Any help much apprieciated

David

[JD Mather]

You didn't mention what release of Inventor you are using.
Project Geometry and use Constraints.

I have not found any CAD program, including AutoCAD, to be much different than another. There is the Rib command in Inventor that would allow you to create this with a single line sketch.

Also, I noticed that your second sketch (Sketch10) was not constrained - missing a dimension.

[Crompton]

Sorry I forgot to say that I am using version 7.
My applogies as well it should be a "rib" not a web.

Ok so i try the rib command.

But first i need to draw the sloping line.
I define a work plane.
from front left to back right. (hope that makes sense, if not write and i will post a diagram)
i project geometry.
and the line is short. (does not go edge to edge)

so how do you attach the end of this sloping line to edges?
or do i just guess.

Dont have to do this in Autocad.

I am trying to learn this superior program, so can you explain how you get to an answer, it might help more than just me.
We all not experts that post on here.

JD what constrain is missing from sketch 10?
I try to move all lines and points and none will move.

Thanks
David

[JD Mather]

Sorry I forgot to say that I am using version 7.
i project geometry.
and the line is short. (does not go edge to edge)

It is difficult to back 7 releases to explain how to do something since the files aren't backwards compatible. If you could download free Inventor LT http://labs.autodesk.com or student version http://engineersrule.org it would be much easier to communicate.

When you project the two edges of the part for the connecting points you should have projected points - not lines. Then sketch a line between the two points.

Or do it the same as in AutoCAD but first project those two edges as points (and a third edge for the triangle) and sketch in a triangle and extrude.

You can see the unconstrained geometry in the attached image. The purple lines indicate unconstrained. One line is totally un-needed and the other line is missing a dimension. You might want to read this document - it is for a later release but the principles are the same.
http://home.pct.edu/~jmather/AU2006/MA13-3%20Mather.pdf