freecad

46 Articles

Reverse Engineering STL Files With FreeCAD

October 21, 2025 by 1 Comment

If you think about it, STL files are like PDF files. You usually create them using some other program, export them, and then expect them to print. But you rarely do serious editing on a PDF or an STL. But what if you don’t have anything but the STL? [The Savvy Engineer] has a method to help you if you need to reverse engineer an STL file in FreeCAD. Check it out in the video below.

The problem is, of course, that STLs are made up of numerous little triangles. The trick is to switch workbenches and create a shape from mesh. That gets you part of the way.

Once you have a shape, you can convert it to a solid. At that point, you can create a refined copy. This gives you a proper CAD file that you can export to a STEP file. From there, you can use it in FreeCAD or nearly any other CAD package you like to use.

Once you have a proper object, you can easily use it like any other solid body in your CAD program. This is one of those things you won’t need every day, but when you do need it, it’ll come in handy.

Want to up your FreeCAD game? We can help. There are other ways to hack up STL files. You can even import them into TinkerCAD to do simple things, but they still aren’t proper objects.

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FreeCAD Foray: Good Practices

September 11, 2025 by 26 Comments

Last time, we built a case for a PCB that handles 100 W of USB-C power, an old project that I’ve long been aiming to revive. It went well, and I’d like to believe you that the article will give you a much-needed easy-to-grasp FreeCAD introduction, Matrix knowledge upload style, having you designing stuff in no time.

Apart from my firm belief in the power of open-source software, I also do believe in social responsibilities, and I think I have a responsibility to teach you some decent FreeCAD design practices I’ve learned along the way. Some of them are going to protect your behind from mistakes, and some of them will do that while also making your project way easier to work with, for you and others.

You might not think the last part about “others” matters, but for a start, it matters in the ideal world that we’re collectively striving towards, and also, let’s be real, things like documentation are half intended for external contributors, half for you a year later. So, here’s the first FreeCAD tip that will unquestionably protect you while helping whoever else might work with the model later.

Okay, we’re all hackers, so I’ll start with zero-th FreeCAD tip – press Ctrl+S often. That’ll help a ton. Thankfully, FreeCAD’s autorecovery system has made big leaps, and it’s pretty great in case FreeCAD does crash, but the less you have to recover, the better. Now, onto the first tip.

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FreeCAD Foray: From Brick To Shell

September 9, 2025 by 18 Comments

Over a year ago, we took a look at importing a .step file of a KiCad PCB into FreeCAD, then placing a sketch and extruding it. It was a small step, but I know it’s enough for most of you all, and that brings me joy. Today, we continue building a case for that PCB – the delay is because I stopped my USB-C work for a fair bit, and lost interest in the case accordingly, but I’m reviving it now.

Since then, FreeCAD has seen its v 1.0 release come to fruition, in particular getting a fair bit of work done to alleviate one of major problems for CAD packages, the “topological naming problem”; we will talk about it later on. The good news is, none of my tutorial appears to have been invalidated by version 1.0 changes. Another good news: since version 1.0, FreeCAD has definitely become a fair bit more stable, and that’s not even including some much-needed major features.

High time to pick the work back up, then! Let’s take a look at what’s in store for today: finishing the case in just a few more extrusions, explaining a few FreeCAD failure modes you might encounter, and giving some advice on how to make FreeCAD for you with minimum effort from your side.

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Software In Progress

February 8, 2025 by 75 Comments

Open source software can be fantastic. I run almost exclusively open software, and have for longer than I care to admit. And although I’m not a serious coder by an stretch, I fill out bug reports when I find them, and poke at edge cases to help the people who do the real work.

For 3D modeling, I’ve been bouncing back and forth between OpenSCAD and FreeCAD. OpenSCAD is basic, extensible, and extremely powerful in the way that a programming language is, and consequently it’s reliably bug-free. But it also isn’t exactly user friendly, unless you’re a user who likes to code, in which case it’s marvelous. FreeCAD is much more of a software tool than a programming language, and is a lot more ambitious than OpenSCAD. FreeCAD is also a program in a different stage of development, and given its very broad scope, it has got a lot of bugs.

I kept running into some really serious bugs in a particular function – thickness for what it’s worth – which is known to be glitchy in the FreeCAD community. Indeed, the last time I kicked the tires on thickness, it was almost entirely useless, and there’s been real progress in the past couple years. It works at least sometimes now, on super-simple geometries, and this promise lead me to find out where it still doesn’t work. So I went through the forums to see what I could do to help, and it struck me that some people, mostly those who come to FreeCAD from commercial programs that were essentially finished a decade ago, have different expectations about the state of the software than I do, and are a lot grumpier.

Open source software is working out its bugs in public. Most open source is software in development. It’s growing, and changing, and you can help it grow or just hang on for the ride. Some open-source userland projects are mature enough that they’re pretty much finished, but the vast majority of open-source projects are coding in public and software in progress.

It seems to me that people who expect software to be done already are frustrated by this, and that when we promote super-star open projects like Inkscape or Blender, which are essentially finished, we are doing a disservice to the vast majority of useful, but still in progress applications out there that can get the job done anyway, but might require some workarounds. It’s exactly these projects that need our help and our bug-hunting, but if you go into them with the “finished” mentality, you’re setting yourself up for frustration.

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Optical illusion gingerbread house from an odd perspective

An Engineer’s Perspective On Baking Gingerbread Houses

December 10, 2024 by 5 Comments

If you’ve ever wanted to merge the worlds of holiday cheer and clever geometry, [Kris Wilk]’s gingerbread house hack is your ultimate inspiration. Shared in a mesmerising video, [Wilk] showcases his 2024 entry for his neighborhood’s gingerbread house contest. Designed in FreeCAD and baked to perfection, this is no ordinary holiday treat. His pièce de résistance was a brilliant trompe l’oeil effect, visible only from one carefully calculated angle. Skip to the last twenty seconds of the video to wrap your head around how it actually looks.

[Wilk] used FreeCAD’s hidden true perspective projection function—a rarity in CAD software. This feature allowed him to calculate the perfect forced perspective, essential for crafting the optical illusion. The supporting structures were printed on a Prusa MK4, while the gingerbread itself was baked at home. Precision photography captured the final reveal, adding a professional touch to this homemade masterpiece. [Wilk]’s meticulous process highlights how accessible tools and a sprinkle of curiosity can push creative boundaries.

For those itching to experiment with optical illusions, this bakery battle is only the beginning. Why not build a similar one inside out? Or construct a gingerbread man in the same way? Fire up the oven, bend your mind, and challenge your CAD skills!

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FreeCAD Version 1.0 Released

November 20, 2024 by 35 Comments

After 22 years of development, FreeCAD has at long last reached the milestone of version 1.0. On this momentous occasion, it’s good to remember what a version 1.0 is supposed to mean, as also highlighted in the release blog post: FreeCAD is now considered stable and ready for ‘real work’. One of the most important changes here is that the topological naming problem (TNP) that has plagued FreeCAD since its inception has now finally been addressed using Realthunders’ mitigation algorithm, which puts it closer to parity here with other CAD packages. The other major change is that assemblies are now supported with the assembly workbench, which uses the Ondsel solver.

Other changes include an updated user interface and other features that should make using FreeCAD easier and closer in line with industry standards. In the run-up to the 1.0 release we already addressed the nightmare that is chamfering in FreeCAD, and the many overlapping-yet-uniquely-incomplete workbenches, much of which should be far less of a confabulated nightmare in this bright new 1.0 future.

Naturally, the big zero behind the major version number also means that there will still be plenty of issues to fix and bugs to hunt down, but it’s a promising point of progress in the development of this OSS CAD package.

The End Of Ondsel And Reflecting On The Commercial Prospects For FreeCAD

November 12, 2024 by 106 Comments

Within the world of CAD there are the well-known and more niche big commercial players and there are projects like FreeCAD that seek to bring a OSS solution to the CAD world. As with other OSS projects like the GIMP, these OSS takes on commercial software do not always follow established user interactions (UX), which is where Ondsel sought to bridge the gap by giving commercial CAD users a more accessible FreeCAD experience. This effort is now however at an end, with a blog post by Ondsel core team member [Brad Collette] providing the details.

The idea of commercializing OSS is by no means novel, as this is what Red Hat and many others have done for decades now. In our article on FOSS development bounties we touched upon the different funding models for FOSS projects, with the Linux kernel enjoying strong commercial support. The trick is of course to attract such commercial support and associated funding, which is where the development on the UI/UX and feature set of the core FreeCAD code base was key. Unfortunately the business case was not strong enough to attract such commercial partners and Ondsel has been shutdown.

As also discussed on the FreeCAD forum, the Ondsel codebase will likely be at least partially merged into the FreeCAD code, ending for now the prospect of FreeCAD playing in the big leagues with the likes of AutoCAD.

Thanks to [Brian Harrington] for the tip.