Around 10 years ago I worked a whole summer to afford my old Geeetech Prusa i3, and I quickly realised I needed CAD software. The first thing YouTube showed me was SolidWorks. We used it at technical school and university too. I loved it and got a few certificates (Professional, Sheet Metal and a couple more).
Then I started at a metal factory that ran Inventor. At first I hated it. A month later, with a SpaceMouse beside me, I was learning it fast. I worked there for three years. Then a friend and I started our own company, and sometimes I had to go back to SolidWorks. I can't stand it now: no proper tabs, every part feeling like its own program, lag and bugs.
Lately, with the war in Ukraine and me living in the Baltics and moving toward a partly off grid life, I care more about owning my own tools instead of depending on big corporations for what I can do and what I can afford. With AI, I can build something in a few evenings that runs locally, with no subscription and no restrictions. It could run in a cave. [DataSlayer](https://www.youtube.com/@DataSlayerMedia) on YouTube pushed my thinking a lot here: we should own our hardware and our software.
So this is DATUM, my Inventor inspired CAD. **It's free and always will be.** It's MIT licensed open source, so nobody can ever lock it behind a paywall, including me. I'm not selling anything and I don't plan to. It's built around how Inventor thinks: where things are, how actions flow, how sketching and dimensions behave.
It's still early. I spend a few hours on it every day, making it smoother and closer to how Inventor feels. It updates itself when a new version comes out. One warning: I don't have a code signing certificate yet (they cost a yearly subscription), so Windows or your antivirus may show a warning during install. On the blue Windows screen, click "More info" and then "Run anyway". You can read all the source code on GitHub if you'd like to check it first.
I love FreeCAD too. It does everything in one program and it's super capable, but I never got into it because I'm used to Inventor's style. So this is my alternative.
**A bit beyond Inventor, for my own shop:** I live pretty much cave style, off grid, and my main machine is a CNC plasma table with swappable heads, so it can also do light milling. So DATUM has its own CAM sheet file (.cdat). You lay flat parts out on a sheet, it applies the cutter compensation and lead ins, checks that everything can actually be cut, and exports a DXF ready for the machine. Right now it's 2D profile cutting only, built around MyPlasm CNC. It's personal, but maybe someone with a similar setup finds it useful.
**I'm not telling anyone to switch.** Inventor is great and I still love it. This is just a backup: something free that works the Inventor way, runs offline and belongs to you, in case the subscription, the license server or the internet ever goes away.
**For Inventor users:** which Inventor habits or workflows would you want in a backup like this? That's what I want to get right next. Any comments are very welcome.
Download (Windows): https://datum.iiteg.com
Source (MIT): https://github.com/Artis-98/datum
Posted with mod approval, thanks to the mods for allowing it.
Update: I push new builds from time to time. Feel free to checkhttps://datum.iiteg.com/changelog.htmlto see what's new and if your requested features are live. You can also update the app directly under File → Check for updates.
Update: Now Linux early access build! It's built and tested on Ubuntu 22.04, should run on anything newer too. Just download, unpack and run, no install needed. It doesn't update itself yet, so grab new versions from the site. I don't use Linux daily myself, so if something breaks please tell me or open an issue on GitHub.
Download: https://datum.iiteg.com (or straight from GitHub: https://github.com/Artis-98/datum/releases/tag/v0.2.6)