Can anyone draw a helix?

[FineThen]

I use AutoCAD 2004 and I am trying to draw a 3D helix object, like a spring or threads on a screw. I have good experiance with the 3D modeling commands, but can't figure this one out.
Thanks
Fine Then

 

[chicopee]

Use the helix equation; calculate X,Y and Z values; plot these values for a full pitch, then 3D array the full pitch and you'll have your helix.

 

[smcadman]

Springs are easy, but threads are another story. Polygons or other shapes rotate about the path-axis as it is extruded. Circles are no problem. Instead of reprinting everything here, go to this site and copy the "spiral.lsp" and "spiral.dcl".

http://www.cadtutorforum.net/forum/viewtopic.php?t=386&highlight=helix

Flores

 

[FineThen]

How do I access the helix equation? I understand the 3D array, after I have the first revolution complete. How do I use this helix equation to draw the first part?

 

[FineThen]

smcadman
Hey. Thanks for the link. I'm not really sure where to put this file. Sorry .lsp extensions are new to me. My best guess would be the path ...\AutoCAD 2004\Sample\VisualLISP\reactors. Am I close?
Thanks again. I can't wait to show my coligues that I've worked this out.

Fine Then

 

[smcadman]

Save it in a folder of your choice, and add the support path. I would recommend saving it in a folder other than in the ACAD install, because if you have to reload ACAD for whatever reason, you may lose all custom files. Make a folder called "My LISP" or whatever and put the routine there.
Enter "options" at the command line.
Go to "Files" tab > "Support File Search Path" > "Add" button > "Browse" button. Find your new folder to add it to the support path.

FYI: There are dozens of "spiral" and "helix" routines, but that is the easiest to use by far because it has a dialog box.

Flores

 

[FineThen]

Awesome!
I had to read up alitte on Lisp files, but I got it to work. Thats opened a whole new world for me.

Thanks
Fine Then

 

[Hawkeye2]

Thomas Register (

http://www.thomasregister.com)

has lots of springs and threads already drawn. Check them out if you haven't already done so.