Clean, exact booleans
Merge and cut on two geometry engines, so exports come out watertight and STEP parts stay exact.
Beta software · Windows
Simple to use. Seriously powerful.
MeldCAD is a free, open-source desktop CAD app built for 3D printing. Snap shapes together as easily as building blocks, then reach for fillets, exact booleans, threads, fits and an editable timeline when the part gets serious.
Features
Building-block easy on day one. Pro tools when you need them.
Fillets, chamfers, shell & draft
Round or chamfer edges in one click, push and pull faces, hollow a part out or add draft.
Editable timeline
Go back to any step, change it, and everything after it rebuilds.
Tolerances & fits
Pick Loose, Slide, Snug or Press and holes print at the right size for your printer’s clearance.
Threads on any hole or peg
Click a round face to add an M2–M24 thread, standard or fine pitch, sized to your fit gap.
Sketch tools & curved text
Trim, extend, offset and fillet in sketches, and bend text into an arch or a ring.
Split for your printer
Cut big models into printable parts with dovetail joints that lock back together.
Joints & motion
Hinges, sliders and gears with collision checks. Play the movement before you print.
Variants
Save Small, Medium and Large sizes of one design and export them all in a single zip.
Technical drawings
Hole callouts, section views and your own dimensions, saved as PDF or SVG.
Paint in color
Paint faces or whole parts for multi-color 3MF in Bambu Studio, OrcaSlicer and PrusaSlicer, or color by height with filament-change pauses.
Pictures to 3D
Turn photos into lithophanes, layered filament pictures or raised reliefs.
Send to your slicer
One click saves the model and opens it in Bambu Studio, OrcaSlicer, PrusaSlicer or Cura.
Simple and Full modes
Simple mode keeps just the essentials on screen. Switch to Full when you want every tool.
Opens and saves 3MFSTLSTEPDXF
How it works
From idea to print bed in three moves.
01
Start from a shape
Drop in a primitive or a ready-made generator, or sketch your own profile and extrude it.
02
Snap, align, refine
Align and mirror parts with a click, then fillet, shell and cut until it’s exactly right.
03
Split & export
Break it into printer-sized pieces with joints and send clean 3MF or STL to your slicer.
Getting started
You won’t feel lost.
MeldCAD guides you from the very first launch, so you can start designing without reading a manual.
Quick setup
On first launch it asks three things: your language, your printer and material, and millimetres or inches.
Guided tour
Make a cup from two shapes in about two minutes. Do each step yourself, or press Do it for me.
Getting started list
A short checklist ticks itself off as you add, size, cut, round, save and print, with Show me buttons along the way.
Tips when you need them
The first time you open a bigger tool, a one-line tip explains it. Turn them off whenever you like.
In your language
Menus, panels, forms, the guided tour and most messages are translated. MeldCAD starts in your Windows language.
Generators
30+ generators with a live preview.
Set a few numbers and watch the 3D preview update. Every generated part stays editable afterwards, so a jar lid or a gear train is a tweak away from fitting your project.
- Gridfinity bins
- Gears
- Jars & lids
- Raspberry Pi cases
- Keycap sets from a layout
- Macropads + firmware starter
- Fidget toys
- Gear fidgets
- Flexi figures
- Image clickers
- Screw bosses
- Vents & ribs
- Lip & groove lids
- Lithophanes
- Fit & gap test prints
Platforms
Where it runs
MeldCAD is a desktop app for Windows. A simpler phone app for Android is being tested, and the two can send files to each other over Wi-Fi.
Windows 11
BetaAndroid phones
In testingmacOS
Not available yetLinux
Not available yet
Open source
Free and open source.
MeldCAD is released under the GPL-3.0-or-later licence. You can use it, read the code and help improve it. Donations help keep development going.
Free to use
No subscription and no account. MeldCAD runs on your own PC.
Open code
The source is public under GPL-3.0-or-later, so anyone can check it, learn from it or contribute.
Supported by you
If MeldCAD helps you, a donation helps pay for new features and fixes.
The code is open, but the MeldCAD name and logo aren’t part of the licence. Please don’t use them for your own versions.
Help shape MeldCAD.
MeldCAD is in a small, invite-only beta for Windows. Leave your email and we’ll reach out when there’s a spot.
Beta means features can still change, and you may run into bugs. Your feedback decides what gets fixed first.
Windows 11 · We only use your email to invite you to the beta. No tracking, no cookies, no mailing list.