[rleigh]

It's because these tools are used to deliver high quality physical products on time and on budget with no scope or interest in messing around with software defects. These tools are treated like physical tools. It's worth paying for a high quality one which won't cause unexpected grief, by people who will provide immediate support because we pay them.

I think if there were good quality open source equivalents they would be considered, but they pose a huge risk, possibly even an existential risk, if they derail our development plans unexpectedly. Paying a lot of money for seriously good quality tools reduces that risk dramatically.

I've had a brief look at FreeCAD, and it's got a lot of potential. But when you compare it with SolidWorks, OnShape or SolidEdge, there's clearly a huge gap in usability and capability which needs closing before a lot of people will be able to consider it seriously. I'm sure it will eventually get there, like KiCAD did, but it will take many years and a lot of investment to get the usability, polish and featureset up to parity. It looks like Ondsel did a really good job to make some progress along that path.

[supermatt]

> when you compare it with SolidWorks, OnShape or SolidEdge, there's clearly a huge gap in usability and capability

All 3 of these are using the same geometry kernel - siemens parasolid.

Most open source CAD software is using OCCT (cascade).

It’s the kernel that brings a lot of the capability. Check out “plasticity” (https://www.plasticity.xyz/ ) for an example of a single developers implementation of the parasolid kernel

[jpm_sd]

I tried plasticity and found it unusable. I couldn't fathom how to design anything without dimensioning!

[eschneider]

It's not even a question of 'good' so much as 'the same as everyone else'. CAD drawing pass through a huge number of hands/companies in the process of getting physical goods made, and any slight compatibility problems can turn into huge costs and lots of blame to go around.

It's very much the case that everyone in the supply chain switches over, or nobody does.

[xyzzy123]

I agree although I feel like one could easily make the exact same comments regarding compilers. I can't quite pin down why there would be many free (for various values of free) industry standard compilers but not cad programs.

[pjmlp]

Because those compilers are mostly sponsored by OS companies to outsource their software development costs in part.

Also notice that all compilers for scenarios where liability is actually imposed, like in physical goods, most compilers are closed source, proprietary, and certified.

[whyever]

Open Source works best for building blocks of software, not for end products. Companies have incentives to share their libraries and tooling, not so much for the final product like a CAD program.

[robertlagrant]

Software engineers find compilers interesting and useful.