[5 YOE] Started a small business 6 months ago, what section should I put it on my resume?

I'm an aerospace structures engineer dealing primarily with composite materials. 6 months ago, I started a business to manufacture composite parts, primarily out of fiberglass and carbon fiber for drones/automotive market.

I do the tooling/mold design, CAM/CNC programming, CNC machining all the way through tool prep, laminating, cure and final trim.

I currently have a 9-5 full time job, so this is really just a hobby-turned side hustle. Should I add this experience under my Work Experience section (if so, before or after my current job's entry) or should I add it to a Personal Projects section on my resume towards the very end?

Thanks!