Automating compliance checks for engineering drawings
What is F4 in a nutshell?
We’re helping hardware-rich teams 10x how they redline and interpret engineering GD&T drawings. With backgrounds at Tesla and SpaceX, we’re building a platform that finally treats drawings like code—automatically validating every dimension, tolerance, and GD&T symbol against standards so noncompliance is caught instantly.
The Problem & Why We Built F4
Drawing literacy is one of the weakest skills across hardware teams. Yet drawings are made every day.
These aren’t just illustrations—they’re effectively business contracts between designers and manufacturers, defining what’s acceptable in production. Drawings carry the bulk of design intent—fit, form, function, and fabrication—and act as the important source of truth across production, quality, and supply chain.
GD&T standards from ASME and ISO exist to formalize this communication. But they’re dense and confusing. Across major revision years, there are thousands of pages of definitions, edge cases, and revision quirks. Designers are expected to know it all, leads are expected to catch every mistake, and suppliers are expected to interpret drawings flawlessly. One mistake means scrap, delays, or worse.
Our Solution
Why is something so critical still so manual? Why can’t drawings be validated and interpreted more quickly and robustly —like code? Why can’t hardware dev be more like software dev?
We’re changing exactly that!
F4 treats drawings like code—they either execute or fail immediately. Our platform checks every dimension, tolerance, and GD&T symbol against standards in real-time, ensuring full compliance before a drawing ever reaches the floor. No more total reliance on manual redlining and reviews.
F4 ensures engineers never release noncompliant drawings—and suppliers never misinterpret them. F4 helps industrial teams eliminate costly scrap, rework, and miscommunication at the root.
How It Works
- Upload a drawing (dxf…and very soon pdf)
- Select GD&T standard of choice (ASME Y14.5 - 1994, 2009, & 2018)
- Get instant compliance score graded against a desired GD&T standard using deterministic logic
- Get recommendation to correct any asset (FCF, FOS, datum, basic, modifier, and/or dimension) of the drawing that is noncompliant with references to ground-truth sources
- With a compliant drawing - get standard definition, inspection plan, and tolerance analysis interpretations on any drawing asset of interest
Hardware Platform Built by Hardware Engineers!
I worked at Tesla as a Mechanical Design Engineer and took 6 parts from clean sheet design to production for the CyberCab and SEMI drive system programs. I was also the lead engineer for Tesla’s global drive unit heat exchanger program with +3 million unit annual production volume.
Aidan worked at SpaceX as an Avionics Test Engineer, where he designed and owned testing hardware (PCB boards and testing apparatus) for the Raptor 3 Engine - the most advanced rocket engine in the world.
In college, we led The University of Alabama’s Rocket Team where we achieved the university’s first-ever liquid rocket engine hotfire! I built the rocket engine and Aidan built the electrical/software for our propulsion system.
https://youtube.com/shorts/rBwsqu_sdeg?si=RgRU_eqib7_-qLcV
Ready to Ditch Manual Redlining?
If you're tired of pretending to be good at GD&T:
- Email us: paul@f4.dev and cantu@f4.dev
