Solidedit and Shell Part 2 - Revenge of the Shell

[Laurel]

Sorry. Couldn't resist the title

Anyhow. I've recently been posting on a thread (Solidedit and Shell) where I managed to get my head around the SOLIDEDIT > SHELL command. I've started this new thread as I have problems with another model.

My problem was with selecting faces (or as it turns out, edges related to faces) in order to remove them from the selection set so that one face is open to reveal the interior. I didn't know which edges to select or why.

I thought I had it cracked, but apparently not.

Please find attached a drawing of a new model. It is simply a box with several edges filleted, but because the edges are filleted, I am unable to work out which edges to select in order to shell the model. The blue rectangle shows the face I want to open. The shell needs to be 2.5mm thick.

I know that I could subtract a relatively easy model to get the same results, but that would not help me learn SOLIDEDIT > SHELL as I want, and the model wouldn't need to be much more complicated in order to make using SOLIDEDIT > SHELL necessary.

[shift1313]

ill try to throw some numbers on there for you but you have to select two edges that define your "plane". that may be a better way to think of it. Then you have to add back in an edge. you will notice when you select two edges that define your face that one of the edge curves(on your fillet) deselect. if you hit add then select one of these that became deselected it will give you what you need.

[shift1313]

sorry i got a little side tracked. here are two figures for you.

i think something that may help you is what cad is looking for. Say with this object you select the two lines that i have shown. your straight line and the arc(fillet) edge. when you add a line back it needs to be the vertical line that divides theses two segments. If you select the edge or center point of your arc i do not believe acad will understand this and your shell will fail. This is simple with cubes because your edge choice is always the divide, arcs are a different story.

give that a shot and let me know if it works for you.

[JD Mather]

My problem was with selecting faces (or as it turns out, edges related to faces) in order to remove them from the selection set so that one face is open to reveal the interior. I didn't know which edges to select or why.

Do not select edges. Select the face and you are done.
When you select an edge you are actually selecting 2 adjacent faces.

Start the command.
Select the solid.
Select in the middel of the face and Enter.
Type the offset distance and Enter.

[shift1313]

JD, i would have said that too but when i tried with his first question Acad wuldnt let me select faces, only edges. i tried in 05 and 07. I know other software packages let you select a face. Are you able to do it in acad?

[Laurel]

Thank you Shifty and JD for your help

Shifty, as you know, I create my drawings using the 2D Wireframe visual style. The PC I use at work is pretty old and cannot easily handly other modes.

After I had successfully tried your suggestion (thank you), it occurred to me that I might be able to select faces rather than the edges that we have been using if I 'HIDE' the rear edges, or use the 3D Hidden style.

It would appear that this is why I have been having problems!! If I use either of the options I described above, sure enough, I can select a face. Exactly as JD describes

A little thing like that (which is not explained in any instructions I have seen) has been giving me (and Shifty ) some grief for the last week!!

[shift1313]

you know its funny i have always had issues with selecting faces using the shell command, and (just for kicks) i played around with it this morning and now its working fine. Im not sure what the issue was for me but i used the hidden line visual style and its very easy to use that way. and now it works fine in other visual styles as well.

glad it worked out for both of us paul

thanks JD!

[JD Mather]

See this document bottom of pg 13 http://home.pct.edu/~jmather/AU2007/...P%20Mather.pdf

AutoCAD has been slow in selecting shaded faces at least since r2007. I do not remember this problem prior to r2007. Try this experiment. Have 4 shaded viewports and run shell. When you pick the face to remove AutoCAD will cycle through all of the faces in all of the viewports (shake, rattle and roll) before it select the shaded face you clicked on. That was supposed to be an animated GIF below. Maybe copy local to see the animation or try the experiment yourself.