Polylines and arcs

[steamwise]

I have a 2D drawing that I created in AutoCad 2006 in order to have some steel work cut using lasers. The drawing was created using simple lines and arcs. I would now like to extrude this 2D drawing in order to incorporate it into a 3D model. I have created another layer and tried to trace using the polyline command, the outline so I can extrude it. Unfortunately I am missing a trick as when I switch from line to arc in polyline mode my arc does not go the way I want. I can either specify Radius or Direction but not both. I have had some success by hitting the esc key which changes the direction of the arc but not always. Any help would be appreciated. Thanks.

[StykFacE]

you don't have to "redraw" over the lines with a POLYLINE.... just use the PEDIT command. this will allow you to convert and join your drawing into a polyline.

or you could use the REGION command, as long as all the lines/arcs are touching at an endpoint, it'll create a region for you to EXTRUDE.

so, my suggestion would be this: type REG in the command line, select your lines & arcs - now you have a region. next, type EXT in the command line, pick your new region, and set the hieght, and do a 3DORBIT to get a look at your newly extruded 3D object.

[steamwise]

Thanks StykFacE, thats got it sorted, nothing like being shown "how" when you are learning. Back to my original question though, suppose tracing was the only way to go about this, what would be the answer to the radius and direction question?. My curiosity will get the better of me if I dont know find out. Thanks again....Mike

[pennylove]

If you were to trace it, and want to do arcs, what you would do (while still in the line portion of pline) is type in "a" for arc, then type in "s" pick the midpoint of the arc and then pick the end point, and then type in "L" to go back to drawing lines in your pline.

hope that helps, it might take once or twice to practice it before you get the hang of it.

[steamwise]

Thanks pennylove for the infomation. I feel I may be being a bit pedantic here in order to satisfy my ignorance. Is it possible with your method to stipulate a known radius. I understand that the second piont will give it direction but as I am tracing over an existing drawing the dimensions are fixed and my cursor will not automatically snap to the mid point of the existing arc, just the end. Thank again...Mike

[CarlB]

You can always enter an osnap in response to a "select point" prompt. So after typing "s" for second type "mid" then pick the arc.

Yes you can also specify a radius. Do you not get that as one of the options after you type "a" ? Then type "r" to input radius, then you pick endpoint of arc.

[steamwise]

I appreciate I may be missing something here, what I have found is that I can either specify radius or direction but not both. If I specify radius, it does not always go in the direction I want. I have spent many hours trying to get it to do what I want but to no avail. I'll go back and digest what you have said. Thanks...Mike

[steamwise]

Thanks CarlB, tried what you said and it works a treat, thanks. I am still curious though as to my original question, how can you stipulate both radius and direction at the same time using the "arc command" in polyline mode.

[steamwise]

Thank you to everyone who has helped me out with this problem. With your help I have now sorted the problem and understand much much more than I did when I started. Thanks...Mike