The project's README from github.com/QymIs-Tech/QymCAD. As one markdown file: README.md.
A parametric associative CAD on a B-rep kernel
Sketch → part → assembly. One program, one project file, no cloud and no subscription.
English · Русский
QymCAD is a desktop CAD for mechanical parts and assemblies: housings, brackets, mechanisms, printed and milled work.
A sketch becomes a solid by extruding, revolving or sweeping; the solid takes holes, fillets, a shell, patterns. Parts come together into an assembly through joints — revolute, slider, rigid. The model is parametric: change a dimension in any operation and everything below it in the timeline rebuilds, the assembly included.
The geometry is exact and solid (B-rep), computed by the OpenCASCADE kernel — the same one FreeCAD runs on. Hence precise surfaces instead of meshes, correct fillets and exchange through STEP with other CAD systems.
The interface is available in English and Russian.
A development build. The program works and is fit for real parts, but it is updated daily.
convert_qcad.py script (see below).Sketching. Lines, arcs, circles, ellipses, splines, polygons, slots, text. Constraints and
dimensions are solved together; dimensions are parametric (w/2, sin(a)). There is construction
geometry and the projection of a body's edges into the sketch.
Parts. Extrude, revolve, sweep, loft, fillet (including a variable radius set at vertices), chamfer, shell, draft, holes (plain, counterbored, countersunk), thicken, patch, stitch, trim, split of faces and of a body, face copy and face push, linear and circular patterns, mirror, booleans, and the primitives: box, cylinder, sphere, cone, torus, prism. Threads are built from a real helical profile with run-outs.
Assemblies. Parts and sub-assemblies, joints (rigid, revolute, slider, cylindrical, planar, ball, pin-slot, parallel), limits and drives, degrees of freedom, an interference check. A sketch can be placed on the face of a neighbouring part as an associative reference: change the neighbour and the dependent part rebuilds.
Exchange. STEP (import and export), STL (import and export), DXF and SVG (import and export of sketches). Either the whole project or a single part or sub-assembly picked in the tree can be written out.
The builds are in Releases. No extra libraries are needed: OpenCASCADE and the dependencies are inside the package.
Windows 10/11 x64 — qymcad-win64.zip. Unpack anywhere and run qymcad.exe.
Linux — qymcad-*.AppImage, a single file. Requires glibc 2.35 or newer: Ubuntu 22.04+,
Debian 12+, Fedora 36+, Arch.
chmod +x qymcad-*.AppImage
./qymcad-*.AppImage
macOS 12+ (Apple Silicon) — qymcad-*-macos-arm64.zip. Unpack it and read README.txt lying beside
the application: the build carries no Apple signature, so the quarantine mark has to be cleared once,
before the first launch. It takes one command and is written out step by step.
The built-in help opens with F1. The articles, with illustrations, live in docs/help.
A document is saved as .qcad. The format changes directly, with no compatibility layer; documents
from earlier versions are brought forward by a separate script:
python3 convert_qcad.py part.qcad # converts in place, keeping part.qcad.bak beside it
The script brings a document forward from any earlier version in one pass and is idempotent.
Linux — just pkg-linux, Docker required. Windows — MSVC with the kernel built from source. macOS — the
kernel from source as well, then packaging/macos/bundle.sh. The details are in
packaging/README.md.
See CONTRIBUTING.md.
The code is distributed under AGPL-3.0-or-later: a fork and any derived build stay under the same licence with open sources.
The OpenCASCADE kernel comes under LGPL-2.1 with an exception and is linked dynamically; the fonts and the icons come under licences of their own. All of it is listed in THIRD-PARTY-NOTICES.md, and that file is placed beside the program in every package.
QymIs Tech — qymis.tech. Author: Denis Kazachenkov.