Three shapes AutoCAD has no command for. SPIRAL draws a flat Archimedean spiral. SLOT draws a slotted hole at any angle. FLANGE draws a bolted flange in plan.
What ShopShapes does
SPIRAL a flat Archimedean spiral - the kind used for coils, springs seen
on edge, scroll details and clock springs. HELIX draws a 3D
helix and cannot do this.
SLOT a slotted hole - two semicircular ends joined by parallel sides,
at any angle. Drawn as ONE closed polyline, so it can be
offset, hatched or used as a trim boundary in one piece.
FLANGE a bolted flange in plan - outside diameter, bore, bolt circle
and any number of bolt holes set out from a start angle.
Note on SLOT. The older SLOT LISP defines a command of the same name, so load one or the other — whichever is loaded second silently replaces the first. SPIRAL and FLANGE clash with nothing.
How to use it
- Load the routine with
APPLOAD, or put it on your support file search path. - Type
SPIRAL,SLOTorFLANGE. - For a spiral, give the start and end radius and the number of turns.
- For a slot, give the width, the length and the angle.
- For a flange, give the outside diameter, bore, bolt circle, hole count and start angle.
How it works
The slot is one closed polyline, semicircular ends and parallel sides together. That is the difference between a shape you can offset, hatch or trim against and four separate objects that happen to line up.
Two corrected defects are worth recording, because both originals were shipped and used in this state.
The slot did (polar lastpoint A B) where A was the slot radius, not an angle — so the straight side ran off at an angle equal to the radius in radians, and the slot only closed when the radius happened to be near zero.
The flange’s validation loop set its two error flags when the bolt circle was out of range, then exited the loop when both flags were set. So it accepted a bolt circle only if it was simultaneously bigger than the outside diameter and smaller than the bore — which is impossible — and looped forever on every valid answer.
Notes and limits
SLOTclashes with the older SLOT LISP.SPIRALandFLANGEdo not clash.- The slot is one closed polyline.
- SPIRAL is flat — for a rising helix use
HELIX3D. - One undo group per shape.
Download and details
| Name | ShopShapes — three shapes AutoCAD has no command for |
| Download | ShopShapes.lsp — 13.3 KB, plain AutoLISP source. Downloads directly; no zip to unpack. |
| Type | AutoCAD AutoLISP routine |
| Commands | FLANGE, SLOT, SPIRAL |
| Requires | nothing beyond a CAD platform with AutoLISP. |
| Source size | 13.3 KB, 329 lines |
| Error handling | Yes — a *error* handler restores every system variable it changed, on cancel as well as on error. |
| Undo | The whole operation is wrapped in a single undo group, so one U reverses all of it. |
| Compatibility | AutoCAD (any release with AutoLISP), BricsCAD, ZWCAD, GstarCAD, ProgeCAD and other IntelliCAD-based platforms. AutoCAD LT needs a LISP enabler. No .NET, no ObjectARX, no installer. |
| Author | YZ, August 2026 |
| Licence | Free to use, supplied “as is” with no warranty. |
References
- SLOT LISP — the older routine of the same command name
- Standard hole and slot sizes — the AISC chart the dimensions come from
- HELIX3D LISP — the rising helix, where SPIRAL is flat
- More free AutoLISP routines on this site
- Wisey’s Steel Shapes — free structural steel section drawing program