Ordinary DIMALIGNED makes you place the dimension line by eye, so a sheet full of dimensions ends up with a sheet full of slightly different offsets. SPANLINE and SPANPICK compute the offset instead.
What QuickSpan does
The dimension line is placed perpendicular to the measured run, one DIMTXT — the current text height — clear of it. Every dimension placed this way sits at an identical stand-off.
SPANLINE is one click: pick a line and it is dimensioned end to end. SPANPICK is two clicks: pick any two points to dimension between.
The consistency is the whole point. A sheet where every dimension sits the same distance off reads as drawn by someone who was paying attention, and it takes less effort than the ragged version.
How to use it
- Load the routine with
APPLOAD, or put it on your support file search path. - Type
SPANLINEand pick a line, orSPANPICKand pick two points. - The dimension is placed at the standard offset. There is nothing to position.
How it works
The offset is one DIMTXT — the current dimension text height — measured perpendicular to the run being dimensioned.
Tying it to DIMTXT rather than to a fixed distance is what makes it scale-correct. Change the drawing scale and DIMTXT changes with it, so the stand-off stays proportionate on paper rather than becoming enormous on a detail or invisible on a site plan.
Both commands modify the drawing, so both open an undo group — a single U removes the dimension.
Notes and limits
- The offset comes from DIMTXT. Set your dimension text height correctly and the stand-off follows.
- SPANLINE needs a line. Use
SPANPICKfor anything else, or for a distance between two features. - It uses your current dimension style for everything else — arrowheads, units, precision.
- One undo per dimension.
Download and details
| Name | QuickSpan — rapid aligned dimensioning at a consistent, automatic offset |
| Download | QuickSpan.lsp — 6.1 KB, plain AutoLISP source. Downloads directly; no zip to unpack. |
| Type | AutoCAD AutoLISP routine |
| Commands | SPANLINE, SPANPICK |
| Requires | nothing beyond a CAD platform with AutoLISP. |
| Source size | 6.1 KB, 146 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
- RISERUN LISP — dimension the X and Y components instead of the direct run
- DIMCLASH LISP — find dimensions that overlap once the sheet is full
- Drawing scale chart — what DIMSCALE and DIMTXT should be at each scale
- More free AutoLISP routines on this site
- Wisey’s Steel Shapes — free structural steel section drawing program