If you need a 3D coil (spring) as a solid body (model), draw a circle (or another profile) and extrude it along the 3D spiral trajectory using the _EXTRUDE command. Or use the SOL_SPRING function in the LSP archive as above (sol_spring.lsp).Since AutoCAD 2007 you can also use the HELIX command.o draw a spiral curve use the 3DSPIRAL function in the SPIRAL.LSP utility-can be downloaded from www.cadstudio.cz/download.