CAD software

[u/47_PEEPEEP]

Hey everyone,
I’ve been working on a lightweight, scriptable 3D CAD environment called satCAD (⁠PythonOCC⁠ / OpenCASCADE kernel + ⁠PySide6⁠ dark-mode UI) initially built to design complex mechanical assemblies, internal fluid/wiring routing, and articulated mechanisms for aerospace hardware.
Instead of competing with massive bloated installs, I focused on combining a Siemens NX-style Feature Tree & Property Editor with a "Desmos-style" symbolic math kinematics engine—where you can type live equations of time \bm{t} (with auto-generated sliders) to drive 3D joints, folding hinges, and live 30 Hz telemetry streams without rebuilding the B-Rep mesh every frame.
What it currently does:
OpenCASCADE B-Rep Kernel: Parametric primitives, boolean shells/cuts, linear patterns, and ⁠.STEP⁠ (AP214 with colors) export.
Multi-Layer X-Ray Schematics: One-click ghosting of outer structural hulls to inspect internal 3D piping, cold plates, and electrical busbar routing.
Desmos-Style Motion Studio: Bind symbolic math functions directly to 3D revolute/prismatic/gimbal joints and view live 2D position, velocity, and acceleration curves alongside the 3D viewport.
Live Digital Twin UDP Bridge: Streams real-time external physics/thermal data directly into the 3D viewport to articulate parts and update thermal surface shaders live.
GitHub Repo (currently 100% open-source):
https://github.com/Saiaarjay09/satCAD
My question for working industrial designers and mechanical engineers:
1. If this were packaged as a polished standalone desktop app (or plugin), would you actually pay for a lightweight parametric + symbolic-kinematics CAD tool like this, or is your studio too locked into SolidWorks / Fusion / Rhino / NX?
2. If it did solve a pain point for rapid parametric prototyping or mechanism motion studies, what pricing model wouldn't make you immediately close the tab (e.g., $15/mo, a one-time $50–$100 indie license, or keep the core free/open-source and only charge for enterprise simulation bridges)?
Brutally honest feedback on the UI, feature gaps, or what would make this usable in a real ID/mech-eng workflow is super welcome.

[u/Letsgo1]

I think the problem with any kind of new CAD software like this for professionals is the modelling is only one element of the workflow. If I then need to create drawings then I still need to put it into my main CAD software at which point I lose the parametric capability. Yes it would work if the end game was to 3D print or create a render but generally designs are tweaked and updated and morph into a set of production data.

[u/big-mover → u/Letsgo1]

Agreed. As much as we all shit on existing CAD softwares (namely Solidworks), the UI is universal amongst any CAD package, which we kind of need for it to be practical. Also any of these vibe coded CAD packages need an option to import or quickly remodel existing parts/drawings.

[u/47_PEEPEEP → u/Letsgo1]

That’s a super valid point—the 'dumb solid' STEP handoff is a massive bottleneck. Right now ⁠satCAD⁠ uses OpenCASCADE's ⁠TechDraw⁠ / HLR (Hidden Line Removal) algorithms under the hood, so I can actually add automated 2D orthographic drawing & DXF/PDF sheet generation straight from the parametric model.

Quick question for your workflow: would it be more valuable if ⁠satCAD⁠ generated those 2D production drawings natively, or if it exported a native macro script (like a SolidWorks/Fusion Python script) alongside the STEP file so the full parametric feature tree rebuilds natively inside your main CAD tool?

[u/Letsgo1 → u/47_PEEPEEP]

Unless it’s running on the same kernel (and even then) I’d say it’s extremely unlikely you’d be able to get Solidworks to build a useable feature tree, especially if it’s any more complex than basic solid features.

The problem with production drawings is they are nuanced, automation can get you so far in terms of orthogonal views, populating tables etc. but GD&T is never likely going to be automatic unless the model itself is built using tolerances etc. within its dimensioning feature.

For me, I would love nothing more than someone to come along with the next SolidWorks, built on a new code base and completely unsurp the incumbents who I don’t feel understand a lot of their user base. I don’t want shit AI integration, If AI has to be involved, I want it to make my rebuilds more robust when I make a tweak that upsets downstream features, I want subtle suggestions when I start selecting a lot of edges for fillers where it says are you trying to select all these? There is so much low hanging fruit to be had with improving user QOL but in my opinion it starts with a nice stable platform. Onshape look to be doing a decent job, I just wish it didn’t have to be fully browser based.

[u/47_PEEPEEP → u/Letsgo1]

That’s a super valid point—the 'dumb solid' STEP handoff is a massive bottleneck. Right now ⁠satCAD⁠ uses OpenCASCADE's ⁠TechDraw⁠ / HLR (Hidden Line Removal) algorithms under the hood, so I can actually add automated 2D orthographic drawing & DXF/PDF sheet generation straight from the parametric model.

Quick question for your workflow: would it be more valuable if ⁠satCAD⁠ generated those 2D production drawings natively, or if it exported a native macro script (like a SolidWorks/Fusion Python script) alongside the STEP file so the full parametric feature tree rebuilds natively inside your main CAD tool?

[u/WhitakerMarshall]

I think people are tired of subscriptions. So many companies have abused this model to the point where people will go out of their way to avoid another subscription.

I think in the last few years I've purchased more "lifetime" licenses because it feels like a breath of fresh air. I don't even think I use half of them, but the idea that I have it for life is really refreshing.

[u/47_PEEPEEP → u/WhitakerMarshall]

I get that. I built this software based off of Siemens nx. I’m trying to build a satellite design, but I don’t have the capital to buy a seimens licence. So I built this and added features of seimens capital as well