Show HN: AI in SolidWorks

[WillNickols]

Hey HN! We’re Will and Jorge, and we’ve built LAD (Language-Aided Design), a SolidWorks add-in that uses LLMs to create sketches, features, assemblies, and macros from conversational inputs (https://www.trylad.com/).

We come from software engineering backgrounds where tools like Claude Code and Cursor have come to dominate, but when poking around CAD systems a few months back we realized there's no way to go from a text prompt input to a modeling output in any of the major CAD systems. In our testing, the LLMs aren't as good at making 3D objects as they are are writing code, but we think they'll get a lot better in the upcoming months and years.

To bridge this gap, we've created LAD, an add-in in SolidWorks to turn conversational input and uploaded documents/images into parts, assemblies, and macros. It includes:

- Dozens of tools the LLM can call to create sketches, features, and other objects in parts.

- Assembly tools the LLM can call to turn parts into assemblies.

- File system tools the LLM can use to create, save, search, and read SolidWorks files and documentation.

- Macro writing/running tools plus a SolidWorks API documentation search so the LLM can use macros.

- Automatic screenshots and feature tree parsing to provide the LLM context on the current state.

- Checkpointing to roll back unwanted edits and permissioning to determine which commands wait for user permission.

You can try LAD at https://www.trylad.com/ and let us know what features would make it more useful for your work. To be honest, the LLMs aren't great at CAD right now, but we're mostly curious to hear if people would want and use this if it worked well.

[areoform]

I have a SolidWorks Students License™©® and it's the most frustrating piece of software I have ever used. Links to tutorials don't work. And when you do manage to get one, the tutorials are designed for older versions of solidworks and point to buttons that have been moved / don't exist where the tutorial tells you to look in the 2025 version.

The UI is the inverse of whatever intuitive is. It's built on convention after convention after convention. If you understand the shibboleths (and I'm guessing most people take a certified course by a trainer for it?), then it's great, but if you don't, it really sucks to be you (i.e. me).

I would LOVE to try out what you've built, but I am afraid that if the model misinterprets me or makes a mistake, it'll take me longer to debug / correct it than it would to just build it from scratch.

The kinds of things I want to make in solidworks are apparently hard to make in solidworks (arbitrarily / continuously + asymmetrically curved surfaces). I'm assuming that there won't be too many projects like this in the training dataset? How does the LLM handle something that's so out of pocket?

[Liftyee]

If it helps, I switched from SOLIDWORKS to Onshape many years ago and the latter has only improved since. The multi-user editing is first class and personally I find the user interface more intuitive (plus, web based = Linux support). I don't need the advanced simulation, analysis, etc. features that SW has over Onshape... yet.

Personally not familiar with curved models, but my understanding is that surface modelling with lofts guided by spline contours might be the way to go. Not sure if SW has those features.

[Gracana]

I love SW and think it's one of the better parametric solid modeling CAD packages out there. It is tough to learn, though. I recommend taking a class or finding a mentor to guide you and answer your questions.

FWIW, back in the day I tried solidworks, inventor, pro e, catia, solid edge, anything I could get my hands on. I struggled to find something that would click with me, thinking it was the software that's the problem. It really wasn't -- the mechanical design problem space is vast and the requirements are demanding, which makes for solutions with a certain level of complexity. I had entered with a lot of hidden assumptions and found it frustrating when the software required me to address them, and on top of that, there's just a lot of stuff to figure out. It helps to have someone around to help when you get stuck.. that was what got me over the hump. At this point I've been using solidworks almost every day for about 15 years, and it only fills me with blind rage every few days, which I think is pretty good for professional software.

[robomartin]

> I have a SolidWorks Students License and it's the most frustrating piece of software I have ever used.

Yeah, you need to invest time to learn it. I do understand the frustration when learning something new. I get it. However, your sentiment on this isn't leading to the correct conclusion. A piano or or a guitar are frustrating instruments until you get past a certain level of mastery.

Engineering tools do carry with them a degree of complexity. There are reasons for this. Some are, of course, better than others. I started in the dark ages with AutoCAD, then, over time, learned used ACAD 3D, Inventor, Pro-E, Solidworks, Fusion 360, Onshape, Siemens NX and CAM tools like Camworks and Mastercam; all in professional commercial, industrial or aerospace (NX) settings. I would rank Solidworks way up there in usability and functionality.

Of course, this isn't to say that there are lots of things that could be improved in Solidworks (and all of the CAD/CAM programs I mentioned).

Sometimes online resources like YouTube can feel (and actually be) really disjointed. Get yourself a good book on Solidworks and go through it front to back. At some point it will click. From that point forward it will feel like an extension of your brain. This is no different from learning to play the piano. When I use Solidworks I don't think about the UI, I just work on my designs.

This is good advice:

https://www.reddit.com/r/SolidWorks/comments/1gjfbwz/comment...

Good PDF course to start with:

https://my.solidworks.com/solidworks/guide/SOLIDWORKS_Introd...

And, of course, you can buy a full course for less than $10:

https://www.udemy.com/courses/search/?src=ukw&q=solidworks

[butvacuum]

Welcome... To The Club!

And yea, you should find a course from a training firm rather than official documentation. It sucks and theres a reason Fusion360 seems to be really eating into the market after 5-10yrs.

[InfinityByTen]

Solidworks and a lot of CAD software is just a GIANT amalgamation of the original software and the work of all of the tiny companies they keep acquiring (basically whosoever built a plugin/competitor for their stuff).

It's most likely so poorly set up that I finch considering working in that domain now.

Source: I've had friends who've worked there. Background: we studied computational engineering, but I got a non-domain software job. Sometimes I feel I learnt more being away from that sort of work.

[starky]

Long time SolidWorks user here with experience in other programs. Frankly, SolidWorks is one of the easiest pieces of CAD software to use, being much more flexible in how things are done compared to a lot of other programs. That said, it is incredibly powerful software, and while someone can learn how to use it in a week, it takes months or years to be actually proficient.

My big tip if you can't find a button there is always the search bar. Just search the command you are looking for, it will even show you where the button is located for next time. That said, they don't move things around that much from year to year, I'm surprised if you can't find a command in a tutorial made in the last 10 years.

The features you are talking about sound like you want to be doing surfacing, which is definitely a more advanced modeling technique that I only recommend trying to learn once you understand the basics and can predict how the software wants you to model something.

[zettabomb]

Solidworks is not even close to the least intuitive CAD program out there. My preference is Autodesk Inventor, which I find to be far easier for beginners to pick up. Fusion 360 is supposedly excellent these days as well. For a real nightmare, try Siemens NX.

[KeplerBoy]

I genuinely envy everyone who thinks SolidWorks is frustrating to use.

I had the pleasure to use both SolidWorks and Vivado professionally over the last decade and boy was solidworks fun in comparison.

[WillNickols]

Every time you put in a query, LAD takes a snapshot of the current model and stores it, so you can revert whatever changes the LLM makes if it messes up.

[mikeayles]

I think we are targeting different ends of the market, but I'm trying to do a full product development pipeline end to end. PCB, enclosure, peripherals, firmware.

https://github.com/MichaelAyles/heph/blob/main/blogs/0029blo...

I need to redo this blog, because I did it on a run where the enclosure defaulted to the exploded view, and kicanvas bugged out, either way, the bones of it is working. Next up is to add more subcircuits, do cloud compilation of firmware, kicad_pcb to gerbers.

Then order the first prototype!

[Liftyee]

Very interesting project! My understanding is that the circuits are human-validated hard coded modular blocks - is this correct? I didn't fully catch how PCB routing and placement is done. I haven't yet seen a credible from-scratch AI schematic design tool (though, admittedly, most of my projects are a mix of repeatable modules and custom circuitry... It would help to have a "known working" setup.)

[carlcortright]

The craziest thing I learned clicking on this post is that solidworks has barely changed in the 15 years since I last used it

[nancyminusone]

Shouldn't surprise you that much. Spreadsheets and word processing haven't changed in decades either.

Solidworks might be as close to a final form for CAD as you're going to get.

[jasongill]

don't worry, the one thing they did change was adding "the cloud" called 3DEXPERIENCE which is universally hated and gets more and more intrusively jammed into each new release.

oh and they changed the price as well, it went up, and up, and up

[iancmceachern]

It's the same for all mission n critical software. Catia, Unix, Matlab, Maya, on and on. This is how you build a industrial base of people with decades of experience to design all these things. If the UI changed every year how would people get truly good at their work?

[OgsyedIE]

CAD and machining are different fields, true, but I see a lot of the same flaws that Adam Karvonen highlighted in his essay on LLM-aided machining a few months ago:

https://adamkarvonen.github.io/machine_learning/2025/04/13/l...

Do any people with familiarity on what's under the hood know if the latent space produced by most transformer paradigms is only capable of natively simulating 1-d reasoning and has to kludge together any process for figuring geometry with more degrees of freedom?

[CamperBob2]

Well, they couldn't generate 2D artwork if they weren't capable of working with multiple output dimensions.

An interesting thing about transformers is that they are world-class at compressing 2D image data even when not trained on anything but textual language ( https://arxiv.org/abs/2309.10668 ). Whether that notion is relevant for 3D content would be two or three figures over my pay grade, though.

[Otterly99]

Commenting on the link you provided: is using a LLM the right approach for this? Why not train a specified model to generate accurate CAD drawings, rather than offloading the task to some LLM that, while it might have some knowledge of machining or CAD conception, will probably fail, because that is not really what it was built for.

[Legend2440]

I think there's a lot of potential for AI in 3D modeling. But I'm not convinced text is the best user interface for it, and current LLMs seem to have a poor understanding of 3D space.

[bdcravens]

Text being a challenge is a symptom of the bigger problem: most people have a hard time thinking spatially, and so struggle to communicate their ideas (and that's before you add on modeling vocabulary like "extrude", "chamfer", etc)

LLMs struggle because I think there's a lot of work to be done with translating colloquial speech. For example, someone might describe a creating a tube is fairly ambiguous language, even though they can see it in their head: "Draw a circle and go up 100mm, 5mm thick" as opposed to "Place a circle on the XY plane, offset the circle by 5mm, and extrude 100mm in the z-plane"

[skybrian]

I think a good UI would be to prompt it with something like "how far is that hole from the edge?" and it would measure it for you, and then "give me a slider to adjust it," and it gives you a slider that moves it in the appropriate direction. If there were already a dimension for that, it wouldn't help much, but sometimes the distance is derived.

I'd love to have that kind of UI for adjusting dimensions in regular (non-CAD) images. Or maybe adjusting the CSS on web pages?

[fragmede]

It's the star trek future way of interfacing with things. I don't know SOLIDWORKS at all. I'm a total noob at Fusion 360, but I've made a couple of things with it. Sketch and extrude. But what I can do is English. Using a combination of Claude and openSCAD and my knowledge of programming, I was able to make something that I could 3d print, without having to learn SOLIDWORKS. Same with Abelton for music. It's frustrating when Claude does the wrong thing, but where it shines is when you give it the skill to render the object to a png for it to look at the scad that it's generating, so it can iterate until it actually makes what you're looking for. It's the human out of the loop where leaps are being made.

[bob1029]

> LLMs seem to have a poor understanding of 3D space.

This is definitely my experience as well. However, in this situation it seems we are mostly working in "local" space, not "world" space wherein there are a lot of objects transformed relative to one another. There is also the massive benefit of having a fundamentally parametric representation of geometry.

I've been developing something similar around Unity, but I am not making competence in spatial domains a mandatory element. I am more interested in the LLM's ability to query scene objects, manage components, and fully own the scripting concerns behind everything.

[carshodev]

Opus 4.5 seems to be a step above every other model in terms of creating SVGs. Before most models couldn't make something that looked half decent.

But I think this shows that these models can improve drastically on specific domains.

I think if three was some good datasets/mappings for spacial relation and CAD files -> text then a fine tune/model with this in its training data could improve the output a lot.

I assume this project is using a general LLM model with unique system prompt/context/MCP for this.

[WillNickols]

Curious what you think is the best interface for it? We thought about this ourselves and talked to some folks but it didn't seem there was a clear alternative to chat.

[knicholes]

So there's OpenSCAD, which is basically programming the geometry parametrically. But... I'd liken it to generating an SVG of a pelican on a bicycle at the current levels of LLMs.

[GivinStatic]

Exactly. May be focus on ideas translation to CAD. Idea generation and concepts are done with drawings. Translate these drawings to CAD and you have improved time to market.

[tsss]

Why do you think that? I can't really think of a use case where AI would be much help to me in the CAD context.

[wojciem]

Totally relatable pain- getting LLMs to reliably drive precise CAD operations is surprisingly hard, especially when spatial reasoning and plane/extrude/chamfer decisions go wrong 70%+ of the time.

For people looking at a different angle on the "text to 3D model" problem, I've been playing with https://www.timbr.pro lately. Not trying to replace SolidWorks precision, but great for the early fuzzy "make me something that looks roughly like X" phase before you bring it into real CAD.

[jehna1]

I've been experimenting with Claude Code and different code-to-cad tools and the best workflow yet has been with Replicad. It allows for realtime rendering in a browser window as Claude does changes to a single code file.

Here's an example I finished just a few minutes ago:

https://github.com/jehna/plant-light-holder/blob/main/src/pl...

[pedropaulovc]

This is amazing! I have no CAD experience and so I tried creating my own bespoke version of LAD a while ago by crawling the SolidWorks docs into a very LLM-optimized format [1] and then asking Claude Code to write C# code using the SolidWorks SDK. Even with docs, it still struggled: functions that fail quietly, extremely verbose code and with no easy way to run tests to ensure that the results are accurate. As an example, here's the 400 lines of code it produced for an eccentric cam [2]. Attempts to close the loop by feeding CC png renders in multiple views had absolutely horrible results. Claude could not differentiate up from down, features etc. I'll try LAD tomorrow, fingers crossed it work better.

[1] https://github.com/pedropaulovc/offline-solidworks-api-docs

[2] https://github.com/pedropaulovc/harmonic-analyzer/blob/main/...

[amelius]

I'd say let's first build an AI that can reliably read datasheets and technical drawings.

I've tried ChatGpt and Claude on datasheets of electronic components, and I'm sorry to say that they are awful at it.

Before that is fixed, I don't have high hopes for an AI that can generate CAD/EDA models that correctly follow some specification.

[JoeDohn]

as mentioned below you need to go vertically on all CADs and reduce your risk. 3DS is a company that lives in 90s, they will simply turn off your access one day without any consideration. (also they have some shit AI chat thing in the "3d experience platform", so for them you are already a threat).

[akiselev]

I've been working on this exact same thing with both Solidworks and Altium! There has definitely been a step change in Opus 4.5; I first had it first reverse engineer the Altium file format using a Ghidra MCP and was impressed and how well it worked with decompiled Delphi. Gemini 3 Pro/Flash also make a huge difference with data extraction from PDFs like foot prints or mechanical drawings so we're close to closing the whole loop on several different fields, not just with software engineering.

For the most part they still suck at anything resembling real spatial reasoning but they're capable of doing incredibly monotonous things that most people wouldn't put themselves through like meticulously labeling every pin or putting strict design rule checks on each net or setting up DSN files for autorouter. It even makes the hard routing quite easy because it can set up the DRC using the Saturn calculator so I don't have to deal with that.

If you give them a natural language interface [1] (a CLI in a claude skill, thats it) that you can translate to concrete actions, coordinates, etc. it shines. Opus can prioritize nets for manual vs autorouting, place the major components using language like "middle of board" which I then use another LLM to translate to concrete steps, and just in general do a lot of the annoying things I used to have to do. You can even combine the visual understanding of Gemini with the actions generated by Opus to take it a step further, by having the latter generate instructions and the former generates JSON DSL to that gets executed.

I'm really curious what the defensibility of all these businesses is going to be going forward. I have no plans on entering that business but my limit at this point is I'm not willing to pay more than $200/mo for several Max plans to have dozens of agents running all the time. When it only takes an hour to create a harness that allows Claude to go hog wild with desktop apps there is a LOT of unexplored space but just about anyone who can torrent Solidworks or Altium can figure it out. On the other hand, if it's just a bunch of people bootstrapping, they won't have the same pressure to grow.

Good luck!

[1] Stuff like "place U1 to the left of U4, 50mm away" and the CLI translates that to structured data with absolute coordinates on the PCB. Having the LLM spit out natural language and then using another LLM with structured outputs to translate that to a JSON DSL works very well, including when you need Opus to do stuff like click on screen.

[WillNickols]

Thanks for the input! Haven't done much with Altium but it seems like you get at least somewhat of a boost for it being slightly more about the logic and less about the spatial reasoning.

2 things related to what you said I hadn't put in the original post:

1. In our experience, the LLMs were awful at taking actions directly with any of the SolidWorks API scripting formats (C#, VBA, etc.). Probably 75% of what they wrote just failed to run, and even when they had access to browse the documentation it wasn't much better. If you're getting Opus or anything else to interact with SolidWorks from the CLI, can you say more about how you're getting it to interface effectively?

2. The LLMs are indeed surprisingly bad at spatial reasoning unless prompted specifically and individually. The most notable case of this is when they need to choose the right plane to sketch on. When creating revolve features, they'll often choose the face that would've only worked if they were going to extrude rather than revolve, and when creating sweeps they'll often try to put the sketch that's going to be swept on the same plane as the path that's being swept. If you go back and ask them why they did that and point out that it's wrong, they can fix it pretty fast, but when left to their own devices they often get quite stuck on this.

[owenversteeg]

>You can even combine the visual understanding of Gemini with the actions generated by Opus to take it a step further, by having the latter generate instructions and the former generates JSON DSL to that gets executed.

Yes, huge +1 for this. I do this in a different field and it's quite impressive. At first it felt weird using different models together but they really do have certain strengths/weaknesses (in January 2026.)

Also, fascinating how quickly things are evolving around PCB design. It was only six months ago that "vibecoding" a PCB was far off (look how basic this was: https://news.ycombinator.com/item?id=44542880) and now that may soon become possible!

[hot_iron_dust]

Interesting! How did you make Claude "know" the PCB layout/schematic specifics? Is just giving it a "reference prompt" enough to produce any interesting results? One thing that comes to mind is to use LLMs understanding of SVG to build "spatial representation" of the board layout by presenting components and tracks as SVG primitives of different type etc. I imagine a practical "PCB Design Copilot" would come from specialized models, trained from the ground up on a large design dataset. There is no GitHub for free professional grade PCB design sources to scrape though.

[hardware2415]

Very interested in your workflow - do you have anything online to share? Also looked into automating altium more and found having to do a lot of GUI work to guide the models along. How much of going from ‘design in head’ to schematic and layout have you automated?

[8note]

have you figured out something like an LSP for returning the constraints back?

ive been starting to play around with 2.5D cad system so i can sketch patterns for leather work and auto-convert into constraints, but id like to be able to have an agent in there too eventually

[arjie]

This is incredible. Coincidentally, I've just started using Claude Code to model things using OpenSCAD and it's pretty decent. The fact that it can generate preview PNGs, inspect them, and then cycle back to continue iterating is pretty valuable. But the things I make are pretty simple.

My wife was designing a spring-loaded model that fits in our baby walls so that we can make it more modularly attached to our walls and she used Blender. Part of it is that it's harder to make a slightly more complex model with an LLM.

Solidworks is out of our budget for the kind of things we're building but I'm hoping if this stuff is successful, people work on things down the market. Good luck!

[ponyous]

Very cool and quite advanced compared to my tool. I've been working on something similar, although not an addon for SolidWorks, but a web SaaS. Initially started it as a tool to help my grandpa make some simple models (ChatGPT clicked for him SolidWorks was impossible).

Still have a long way to go, but if anyone wants to try you can do it here: https://grandpacad.com

If you want more free credits send me an email and I'm happy to give you some.

[Tossrock]

> but when poking around CAD systems a few months back we realized there's no way to go from a text prompt input to a modeling output in any of the major CAD systems.

This is exactly what SGS-1 is, and it's better than this approach because it's actually a model trained to generate Breps, not just asking an LLM to write code to do it.

[jwr]

FWIW, I've been testing MCP tools exposed from Autodesk Fusion (https://github.com/AuraFriday/Fusion-360-MCP-Server) and the results are quite promising. It's especially good as a quick starting point.

[nico]

Would love something like this for Fusion 360. Being able to just prompt the UI to create or edit objects. It would be cool if (like with coding agents in which you can add context using @filepath), you could use the mouse to click/select context objects for the prompt to execute with

[ricksunny]

Skip mechanical LLM; iterate on mechatronic LLM instead https://github.com/ricksher/ASimpleMechatronicMarkupLanguage

[waynenilsen]

> the LLMs aren't as good at making 3D objects as they are are writing code

I am still hoping that openSCAD or something similar can grab hold of the community. openSCAD needs some kind of npm as well as imports for mcmaster-carr etc but I think it could work.

[nsoonhui]

This is interesting, how do you get it done? From what I know CAD tools generally don't support text file, only binary blob which is LLM unfriendly?

Do you consider adding support for AutoCAD or AutoCAD vertically integrated software like Civil 3D?

[WillNickols]

The conversation itself is sent to the LLM in regular text, and in addition it sees the feature tree (also text) and often a screenshot of whatever the current model looks like. This is usually enough for the model to know what's going on.

Yes - we're likely looking into other 3D systems in the future.

[doctorpangloss]

it's definitely interesting, but the demo of the coffee mug has a lot of flaws, are there some concrete examples you can think of where the hosted LLMs really shine in this problem?

[jasongill]

What are the flaws?

I've watched the video a couple times and the only thing I can see that it does wrong is the fillets on the handle (and maybe the way it used a spline & sweep for the handle could have been improved but it's no worse than you'd see from a new Solidworks user).

[WillNickols]

Honestly, the out-of-the-box models aren't great at CAD. We were mostly trying to figure out (1) how well it could do with the best harness we could give it and (2) whether people would want and use this if it worked well.

[PonyoSunshine]

Congratulations. I have been pondering myself if I could do something similar with Rhino. Is there any chance this can be adopted to other platforms like Rhino?

[skeptrune]

Wow, this is really cool. Now I want to go and get a windows machine and solidworks license again just to play with this.

[proee]

How about support for Fusion 360?

[WillNickols]

Would you use something like this if it worked well in Fusion 360? We chose to start with SolidWorks because when talking with people in mechanical engineering, almost everyone was using SolidWorks and no one even mentioned Fusion (despite online surveys saying it's like 45/45).

[Jemm]

Windows Defender is flagging this as containing Sabsik.EN.A!ml

[layer8]

Should have called it ChAD (Chat-Aided Design).

[sl_convertible]

We're getting closer and closer to Jarvis.

[iancmceachern]

Cool, I'll check it out!!

[fallat]

Why would I just not use some local desktop Agent?... Like what

[crobertsbmw]

I’m just a grumpy old man, but I like having to do it the hard way. I liked having to code the hard way too. With all the AI vibe coding stuff I now feel like I’m stupid for doing it the hard way. And I probably am. I would definitely think someone else was stupid if they were using an axe to cut down a tree when there’s a chainsaw sitting right next to them. Or if someone was writing assembly code when anything else would do just fine… I guess I feel sad that the AI gets to take over a lot of the mundane but also often times relaxing and fun parts.

[ipnon]

I feel like I am still doing it the hard way, I just have to type 10x less into my keyboard to get the same amount of code out. But as soon as my understanding of the system diverges from its reality, I still do the old fashioned work of figuring out the difference and how to resolve it. It feels like a printing press replacing scribes to me.