Free Alternative to AutoCAD

I spent three weeks using FreeCAD 0.21.2. The interface hits you with a dense wall of toolbars. It feels like software designed by engineers for other engineers. The learning curve is steep. You will spend your first two days reading wiki pages just to understand the Part Design workbench. Once you grasp the workflow, it becomes an incredibly capable tool. I imported a 120MB STEP file containing a full engine assembly. My M2 Mac Studio handled it without stuttering. The constraint solver works predictably. You do need to watch out for the topological naming problem. Modifying a base sketch can break downstream features. The developers are fixing this in the upcoming 1.0 release. It remains the most capable free tool available for physical product design.

LibreCAD looks like it belongs on a Windows 95 machine. I do not care. It does exactly one thing. It draws 2D lines. I loaded version 2.2.0 and immediately started typing familiar AutoCAD commands. Many of them map perfectly. You type 'L' for line and 'TR' for trim. The muscle memory translates nicely. It saves natively in the DXF format. I sent a LibreCAD DXF to a local laser cutting shop. They opened it on their proprietary Windows software without a single error. The app struggles with massive files. I tried opening a city block topography map. The zooming got choppy. Stick to single-part profiles or basic floor plans.

QCAD is the software LibreCAD was forked from. I tested QCAD 3.29. It feels significantly more modern. The property editor sits neatly on the right side. The layer manager behaves predictably. The catch is the licensing. The Homebrew installation gives you the Professional trial. You have to manually delete the trial plugins from the application bundle to get the free Community Edition. I spent five minutes digging through the Finder to trash those specific files. The Community Edition works brilliantly. It handles standard 2D drafting tasks with ease. The snap tools are highly accurate. It lacks the advanced DWG support of the paid version. You will need to rely on DXF files.

You do not draw in OpenSCAD. You write code. I opened version 2021.01 and stared at a blank text editor. You type commands like 'cylinder(h=10, r=5);' and hit render. The 3D shape appears on the right. This approach sounds terrible for visual artists. It is absolutely brilliant for 3D printing functional parts. I wrote a script to generate custom shelf brackets. I could change the thickness variable from 5mm to 8mm. The entire model updated perfectly. You can track your CAD files in Git. You can see exact diffs of your design changes. The render engine bogs down on highly complex mathematical shapes. Threaded rods with realistic pitch will freeze the preview window.

The SolveSpace application file is under 10 megabytes. I downloaded version 3.1. It opens instantly. The interface consists of a black void and a few floating text menus. It looks intimidating. I spent an hour following a basic tutorial. I realized the underlying constraint solver is magical. You draw messy lines. You apply constraints like 'parallel' or 'equal length'. The shape snaps into perfect geometric alignment. I modeled a 3D linkage mechanism. I could actually grab one arm and drag it to watch the kinematic motion. It calculates mechanical movement better than apps that cost thousands of dollars. It fails completely at organic shapes. You cannot model a computer mouse here.

Blender is not a CAD program. It relies on polygons instead of mathematical curves. I installed version 4.1 anyway to test the CAD Sketcher add-on. The results surprised me. I could draw exact 2D profiles with dimensional constraints. I extruded them into 3D meshes. The workflow feels clunky compared to dedicated engineering software. You have to constantly switch between object mode and edit mode. The benefit is the rendering engine. I modeled a custom mechanical keyboard case. I immediately threw materials on it and rendered a photorealistic image using Cycles. It handles millions of polygons without breaking a sweat. You just cannot export true STEP files for CNC machining.

Autodesk offers a free version of Fusion for personal use. I downloaded the installer directly from their site. It runs natively on my M2 Mac. The interface is beautiful. The timeline at the bottom tracks every sketch and extrusion. You can roll back time and fix a mistake. The software recalculates the rest of the model automatically. I love using it. I hate the restrictions. Autodesk limits you to 10 active documents. They removed the ability to export certain file formats from the free tier. Your files live on their servers. You are completely at the mercy of their next policy change. It performs flawlessly right now.

AutoCAD is massive overkill for interior design. I installed Sweet Home 3D version 7.4. It requires Java. That usually means a sluggish interface. It actually runs quite smoothly. You draw walls in a 2D grid. The app generates a 3D view in the bottom panel simultaneously. I mapped out my entire apartment in about twenty minutes. I dragged standard furniture models from the sidebar into the rooms. You can change the dimensions of a couch to match real life. It exports decent PDF floor plans. It will never replace AutoCAD Architecture for structural engineering. It perfectly handles residential layouts.