An automated drafting too where I can describe design intent and requirements would be a million times better, especially if it is CAD context aware.

I would say around 5-20% of mENG is not actually modelling, the endless pursuit of text to cad and other ai works is both not helpful and not enjoyable

(PS: The feature tree renaming does look very useful)

The key question is: why would your tool or harness perform better than the frontier model providers’ own native tools, such as Claude for Creative Work, if your product is only a thin layer on top of their model or their agentic system?

Similarly, why would your tool work better than a CAD company’s own agentic tool? For example, it would not be very difficult for PTC to add an Onshape co-pilot that calls the Claude Agent SDK, while PTC can also build more powerful internal tools/MCP servers for their own use without exposing them to external API users.

I have been working on GrandpaCAD[0] for a while, a very similar product. I thought of you as my biggest competitors but noticed recently you are focusing more and more on professionals while I am focusing on total noobs in modeling who just want to whip out a quick model. So I guess we are not competitors anymore?

My evals[1] show that Opus 4.7 and GPT 5.5 are very comparable in terms of generation quality, but GPT 5.5 is slower and costs sooo much more in my harness. And the original breakthrough model was Gemini 3.1. I'm curious do you have more written about your benchmarks setup?

If you want to chat email is in my profile. Btw, just met "your"(?) neighbour on a plane a couple of days ago. World is small.

[0]: https://grandpacad.com

[1]: https://grandpacad.com/en/blog/public-benchmarks-misled-me-o...

One task that is always time consuming for a mech design team is generating library parts. Mcmaster carr or other vendor model downloads are one thing, but they never have everything you need, and I don't want a separate model for each and every size/configuration of part. There are still plenty of parts that you can't get a model so have to generate it from scratch using data and pictures from a pdf catalogue.

I want a single model containing all the available configurations of that product.

I just had a go with the Onshape connector to generate such a model of a simple BSPT hex reducing nipple for piping. It looks promising but didn't quite get there and hit the daily token limit while I was trying to get it to fix the model.

FYI when I hit the token limit and click the 'See plans' link, I get "Application error: a client-side exception has occurred."

I will say I explored this reasonably deeply and came away with the conclusion that even though we have OpenSCAD and all these examples, LLMs are still very weak at spatial reasoning compared to diffusion models.

You can do all sorts of tricks like have a parts library to get around this and do physics checks but another inconvenient truth is whenever you design a complex assembly, every change to that part needs to be aware of the other parts in the design -- thus you need a global part-aware editing capability from diffusion.

That's getting solved already in china leading labs, and bottlenecked by the lack of good training data, which china is solving with mass labor.

This will be solved overseas first before we will in the US.

And does this use your OnShape API quota? If it's making a new API call for each individual feature, I could see this blowing through the annual quota very quickly. What does this look like in practice?

Would a more CAD-as-code based approach to CAD design be more suitable?

Just like, LLMs have an easier time to build a presentation with latex than with powerpoint...

This is just one example of a superior tool that's natively easy for LLMs to interact with, because the source files are just composable scripts containing lists of shapes and then lists of tools and parameters to apply to the shapes.

I wrote a simple set of system prompts you can use in any repo to show any LLM how to make SCAD files with a whole bunch of cool examples. This is just another example where walking away from the bloated, inferior feudal system of SaaS and cloud models leads to simpler processes and outcomes with superior results in less time, for free.

https://github.com/cjtrowbridge/vibe-modeling

It does not integrate with "my" CAD, which happens to be none of the two closed-source, closed-ecosystem, commercial products you built your tool for.

I kind of cautiously disagreed. He told me that the applications he used had no tooling for AI.

I basically said "give it six months". I think in my googling now, it's already here.