CAD for 3D printing, without the CAD software
You have a printer and a part you need. Describe it in plain English with its dimensions, get an editable parametric solid, and export an STL your slicer will accept. No install, no licence, no interface to learn.
The problem is the modelling, not the printing
Most people who own a 3D printer are not short of things to print. They are short of models for the specific things they need. The generic objects are already on model sites. The bracket sized to your shelf, the replacement knob for your oven, the adapter between two fittings you happen to own: none of those exist to download, because nobody else has your problem.
The traditional answer is to learn CAD. That is a genuine investment, and for a large share of printed parts it is more than the job requires. A mounting plate with four holes is fully described by seven numbers. Drawing it should not take an afternoon of learning sketch constraints.
The alternative is to state those seven numbers and let the geometry be generated. That works precisely because printed parts are usually describable: they are prismatic, dimensioned and functional rather than sculpted.
Why CAD rather than a mesh
Plenty of AI tools will produce a 3D shape from a description. Most produce a mesh: a shell of triangles that looks correct and carries no engineering geometry. There is no hole with a diameter, only facets arranged in a hole shape, and frequently the surface is not closed, so the slicer refuses it.
TextoCAD writes parametric modelling code and executes it against a CAD kernel. The result is a real solid: watertight because it was built as a solid, editable because every dimension is a named parameter, and exportable as STEP as well as STL. The difference is set out in full in AI CAD generators compared.
What you get
Built for parts that have to fit
Real solids, not meshes
Models are built as B-rep solids by a CAD kernel, so they are watertight by construction and slice without repair. Export STEP as well as STL.
Every dimension stays editable
Wall thickness, hole diameter, overall size: each becomes a slider you can move after generation, which is exactly what the print-measure-revise loop needs.
Nothing to install
It runs in the browser. No licence to renew, no workstation requirement, no account tier that makes your designs public.
Printing allowances in the prompt
State a 4.5 mm hole for an M4 bolt and a 0.5 mm bottom chamfer, and the model arrives print-ready rather than needing a correction round.
Built for the parts people print
Brackets, plates, spacers, adapters, enclosures, standoffs, gears and jigs. The parts that are tedious to model and trivial to describe.
Reference images accepted
Attach a photo or an annotated sketch alongside the dimensions when the shape is easier to show than to write.
The numbers that decide whether a print works
Most failed prints are design problems the printer reproduced faithfully. Four numbers prevent the majority of them, and all four belong in the prompt.
Wall thickness should be a whole multiple of your nozzle width. With a 0.4 mm nozzle: 0.8 mm minimum, 1.2 mm for load, 2 mm or more for an enclosure.
Hole diameter needs about 0.2 mm added for a bolt clearance hole and about 0.4 mm for a bearing seat, because FDM holes print undersize.
Overhangs beyond roughly 45 degrees from vertical need support. A chamfer prints where a ledge does not.
A 0.5 mm chamfer on the bottom edge pre-empts elephant foot, the slight flare where the first layer is squashed into the bed.
Each of these is covered with the reasoning behind it in design for 3D printing, which also explains how to calibrate the allowances to your own machine in a single test print.
From description to sliced file
Describe the part with its dimensions. Check the generated numbers against your own and correct them on the sliders, which is faster than re-prompting and does not spend a generation. Ask for changes in plain English where the geometry itself needs to change. Export an STL for the slicer and keep the STEP so you can revise the part in a year without starting again.
The full walkthrough is in text to CAD for 3D printing, and CAD prompt examples has twelve prompts you can copy and adapt.
Where this is not the right tool
It is worth being straight about the limits. Sculpted and organic work, figures, miniatures and decorative pieces are better served by a mesh modeller such as Blender, and a mesh is the correct output for them. Large assemblies with mates and interference checks are still traditional CAD territory. And a design that depends on judgement rather than description will always be faster to draw than to specify.
For the honest version of that comparison across every major tool, see CAD software for 3D printing.
Frequently asked questions
What CAD software do I need for 3D printing?
You need something that produces a closed solid and exports a mesh. That can be a traditional package such as Fusion 360, FreeCAD or Tinkercad, or you can describe the part instead of modelling it. What matters is that the output is watertight, because a slicer has to be able to tell inside from outside.
Can I design for 3D printing without learning CAD?
You can skip the software, not the knowledge. Describing a part removes the modelling effort entirely, but you still have to know that a wall should be a multiple of your nozzle width and that a hole needs clearance. The prompt is where those decisions get made.
What wall thickness should I use for 3D printing?
A whole multiple of your nozzle width. With the standard 0.4 mm nozzle that means 0.8 mm as an absolute minimum, 1.2 mm for anything structural, and 2 mm or more for an enclosure that gets handled. A 1 mm wall is two beads plus a gap, and the gap is where it fails.
Why do my printed holes come out too small?
The printer approximates a circle with straight segments that sit inside it, and the plastic contracts as it cools. Both pull the hole inward. Add roughly 0.2 mm to a clearance hole and 0.4 mm to a bearing seat, and expect vertical holes to be closer to nominal than ones printed on their side.
Should I export STL or STEP for 3D printing?
STL for the slicer, because slicers expect a mesh. Keep the STEP as well. STL carries no units and no editable dimensions, so a part that exists only as an STL is a part you cannot properly change later. Export the mesh, keep the solid.
Is this free to use?
Your first 2 generations are free after you sign in, and adjusting dimensions with the sliders plus STEP and STL export stay free. Paid plans add a more powerful model and higher monthly limits.
Can it design parts that fit something I already own?
Yes, and that is the case where it is most useful, because no downloadable model can exist for your specific object. Measure the original with digital calipers to 0.1 mm, state those dimensions in the prompt, and add clearance on anything that has to mate.
Describe the part you need to print
State the dimensions, adjust them on the sliders, and export an STL ready for your slicer.