Draw a centerline like a polyline and CADdillo renders it as a true double-line run — walls at the actual outside diameter, corners turned into radiused elbows, joints that couple when runs meet. It runs in a browser tab, it is free, and the DXF opens in AutoCAD.
Nothing to install. 2D plan drafting — not 3D, not BIM.
The centerline is the entity. Everything a drafter sees — walls, elbows, end caps — is generated from it, which is why moving or stretching a run leaves you with a run instead of a pile of disconnected lines.
The PIPE command (alias PI) works like a polyline: click a start point and keep clicking. You are drawing a centerline, and the two wall lines appear as you go, offset at the real outside diameter of the size you picked. Type a length while you drag and the segment goes exactly that far — feet-and-inches accepted, so 4' 6" is a valid entry.
Every corner you draw is generated as a radiused long-radius elbow at 1.5 times the outside diameter, the plumbing and process default. You get true heel and throat arcs rather than a mitred corner, plus three snappable points per bend so a dimension or the next run can attach to the actual geometry.
Land a same-size run on an existing end and the two couple: the caps disappear and the walls flow straight through. Pull them apart and the joint reopens. Click any run to change its size from the properties panel, run TRANSITION to taper between two sizes, then export DXF.
A 2 inch pipe is 2.375 inches across the outside, and that is what a plan has to show. CADdillo draws from the standard tables rather than from the nominal number, so a run occupies the space it will actually occupy.
1/2 inch through 4 inch at true outside diameters. Steel and PVC share the same ODs — that is the point of the schedule system, where wall thickness changes and the outside does not — so one table serves both.
DN15 through DN100 at ISO outside diameters. These are not the imperial table converted: DN50 is 60.3 mm where 2 inch Schedule 40 is 60.325 mm. A metric drawing carries the metric number.
Bends generate at 1.5 times the outside diameter with real heel and throat arcs, and three snap points each so dimensions and adjoining runs attach to the actual bend rather than to a corner that isn't there.
A custom diameter is always allowed. The size picker offers the tables as a convenience, not a constraint, so an odd size or a round duct run is a number you type.
This is what shipped. We would rather you find the limits on this page than ten minutes into a drawing.
Yes — CADdillo's editor is free to use at app.caddillo.com and the PIPE command is part of it. There is nothing to install and no CAD licence involved. You draw the centerline and it renders the run as true double-line geometry at the real outside diameter, then exports DXF.
Real sizes, from standard tables. Pick 2 inch and the walls sit 2.375 inches apart, because that is the Schedule 40 outside diameter — nominal size is not the drawn size, and the tool uses the correct one. Imperial covers 1/2 inch to 4 inch; metric covers DN15 to DN100 at ISO outside diameters. A custom diameter is always allowed for anything outside the table.
No. Every corner in a run is generated as a radiused elbow automatically, at the long-radius convention of 1.5 times the outside diameter. The heel and throat arcs are real arcs, not an approximated corner, and each bend exposes three snap points so you can dimension to it or start another run from it.
Yes. Select the run and choose a different nominal size in the properties panel — the walls and every elbow regenerate at the new diameter. MATCHPROP copies a size from one run onto others, which is the fastest way to resize a whole branch at once. Use TRANSITION (alias TRA or REDUCER) where a run genuinely changes size.
Yes. DXF export writes the drawn double-line geometry along with the centerline and the size data, so someone opening it in AutoCAD, BricsCAD, LibreCAD or DraftSight sees the complete drawing rather than a bare centerline. Reopening the same file in CADdillo restores the runs as live, editable runs.
