Say you need a 3D model. It might be a bracket to hold a shelf, a case for a circuit board, a replacement for a snapped plastic clip, or a hook the right size for your bike. You have a 3D printer, or a friend with one, and you know exactly what you want. What you don't have is the time to learn CAD.
Until recently you had three options: learn a beginner tool, learn a professional one, or hope someone had already uploaded the part you need. A fourth has arrived: describe the part in plain English and let an AI assistant build a real, editable 3D model for you. That's what partforge does.
This post compares the options honestly, including the cases where partforge is not the right choice.
The quick answer
| If you want to… | A good fit |
|---|---|
| Learn 3D modeling as a skill, or teach it to kids | Tinkercad |
| Design complex products and assemblies professionally | Fusion 360, Onshape, SOLIDWORKS |
| Use free, open-source CAD and don't mind a learning curve | FreeCAD |
| Make a character, a sculpture or a decorative figure | An AI mesh generator (text-to-3D) |
| Get a precise, printable part without learning any of the above | partforge |
The rest of this post explains why.
Beginner CAD: Tinkercad and friends
Tinkercad is great, and it's free. You build models by dragging boxes, cylinders and other shapes around and combining them. For simple objects it's quick to pick up, and it's how a lot of people start.
The catch shows up when a part needs to be exact. Lining up holes at an exact spacing, rounding an edge, cutting a screw thread, or making a lid that fits its box with the right gap all take a lot of careful clicking. Change one measurement later and you often have to rebuild several steps by hand.
With partforge you say the numbers instead of placing them: "two holes 40 mm apart, rounded corners, and a lid with a 0.3 mm gap so it slides on." When you change your mind, you say that too.
Professional CAD: Fusion 360, Onshape, SOLIDWORKS, FreeCAD
These are the real thing. Engineers design cars, medical devices and consumer products in them. They can do almost anything, and if you design parts every day, learning one is worth it.
But they're built for people who use them every day. Sketches, constraints, feature trees and dozens of toolbars take weeks to get comfortable with. For someone who needs a part now and then, that's a lot to learn to make one enclosure.
partforge still gives you a real CAD file. Designs export as STEP, the standard format those programs open, as well as STL and 3MF for your slicer. If a part ever outgrows partforge, you can hand it to someone who uses Fusion 360 and they can pick it up from there.
AI text-to-3D generators
Tools that turn a prompt into a 3D model are everywhere right now, and for characters, creatures, statues and decorative pieces they're impressive.
Most of them produce a mesh: a shell of thousands of tiny triangles that looks right. That's fine for a figurine, but a problem for a functional part:
- The dimensions are approximate. A "20 mm hole" might be 18 mm, or oval.
- You can't easily change one measurement. You generate again and hope.
- Details that make a part work, like flat mounting faces, exact clearances and threads, usually aren't there.
partforge builds geometry, not a mesh. Every size is a real number you can read and change, which is the difference between "looks like a bracket" and "fits the bracket holes on your wall."
What using partforge is like
- Describe the part. "A wall hook that holds a bike by the top tube, with two screw holes." Rough is fine; you can give exact numbers now or later.
- Watch it appear. The assistant builds the model in front of you, then looks at it from several angles and measures it to check its own work.
- Change it by asking. "Make it 10 mm deeper." "Round all the edges." "Add a lip so the bike can't slide off."
- Use the sliders. The important dimensions become controls you can drag yourself, without another message.
- Export and print. STL or 3MF for your slicer, or STEP for other CAD tools.
A few things that help with real, functional parts:
- Start from a photo. Attach a picture of the broken part or the thing it needs to fit. Add one or two real measurements, since a photo shows shape but not size.
- Design around something you already have. Import an STL, STEP or 3MF file (a circuit board, a motor, an existing part) and build a case or adapter around it.
- Rounded edges, threads, text and curves. The details that make a printed part feel finished and hold up in use.
- You keep the design. Every forge is saved as readable instructions with its full history, so you can go back to any earlier version or download the whole thing. More on that in A forge is a program, not a mesh.
- A library to start from. Browse parts other people have shared, open one, change a number and make it your own.
When partforge isn't the right tool
Being honest about this saves you time:
- Organic, sculpted shapes such as faces, animals and flowing art pieces. Use an AI mesh generator or a sculpting tool.
- Large, multi-part product design where a team manages hundreds of parts, drawings and tolerances. Use professional CAD.
- Learning CAD for its own sake. Tinkercad or FreeCAD will teach you more, because you do every step yourself.
For everything in between, the brackets, boxes, mounts, clips, jigs, adapters and replacement parts that make up most of what people actually print, describing it is usually the fastest way to get it right.
Try it
Open partforge and describe the part you've been putting off modeling. One sentence is enough to start.