Properly extruding out a square HSS

Hi All!

I'm setting up so isometric views with legacy hidden settings so it properly displays as it would in real life. I started out by making 2 rectangles (one 1/4" bigger than the other) and centered them together.

I then turned it into one polyline so I could extrude it.

But now it thinks that it's one big chunk of metal in the center, and not hollow. I don't know how to get a hollow piece of something.

How would you guys make a hollow object that had a wall width??

THANKS!!

What version of AutoCAD are you really using? (your profile says LT 2011)

Assuming you are not using LT - I would Sweep a Region, no extra Subtract work needed.

http://home.pct.edu/~jmather/content/CAD238/AutoCAD%202007%20Tutorial%208.pdf

The advantage of Sweep over Extrude is that you can set up your skeleton and Sweep the Region profile along any path without having to align the profile.

You are doing this in full AutoCAD? If so you need to subtract the inner one from the outer one.

I exaggerated the inner core so you could see there were actually two extruded objects. After the subtraction you get the result on the right.

Good example, Mark.

FWIW, one less step would be to PRESSPULL the profile. This method takes away the need to subtract two solids.

Assuming you are using LT then use the thickness command and create 2 regions for the end of the tube (and subtract the smaller one from the larger)

Thanks for the help guys, the subtract command is new to me. great solution!

I haven't yet worked out the sweep command, but I am familiar with the method. My concern with this method is that I know if you extrude a line you get a solid plane that has minimal thickness. Would a sweep of a HSS outline (let's say I make it a pline so it's all one piece) create a solid object or would it just sweep the lines in a plane and not actually create a solid? Hopefully that makes sense

I've recently changed jobs and am now using Autocad 2012. I am doing this in 3d, sorry for the confusion. Ill update my profile.

Thanks to each of you for your help, I have a working solution now and better understanding!!

SWEEP command can be reviewed here: http://exchange.autodesk.com/autocad/enu/online-help/search#WS1a9193826455f5ffa23ce210c4a30acaf-5303.htm

It is very powerful and can be used to create 3D models very efficiently in AutoCAD.

.... I know if you extrude a line you get a solid plane that has minimal thickness.

No, if you extrude a line you get a planar surface body that has zero thickness.

See page 5 for discussion on surface bodies and solid bodies.

http://home.pct.edu/~jmather/AU2007/GD211-2P%20Mather.pdf

The paper I referenced earlier would create solid bodies with the Sweep command.