You've been around machines and mechanical systems enough to have picked up some basic understanding of how things work. Maybe you grew up in a family that worked with machinery, or you just spent enough time around repair shops and technical environments to absorb some knowledge.
You're not some master technician who can rebuild starship engines from memory, but you know enough about mechanics to understand basic repairs and maintenance. Whether through helping out with family projects or just being naturally curious about how things work, you've developed some familiarity with tools and mechanical systems.
Upgrade your trusty utility belt to gain an additional +1 bonus for those times when you need a thingy-ma-bob, it's bound it be in your belt.
Your trusty multi-tool counts as a tool kit, for any three engineering skills, select which skills when you pick this legacy item, once sleeted these cannot be changed.
You can understand and repair most technologies, regardless of their origin or complexity.
Given the right parts, you can modify or create new devices, pushing beyond their original designs.
Just a glance, a sound, or a single touch, and you can often identify what's wrong with a machine.
Even in situations with limited tools or parts, you find ways to get machines up and running.
You can't leave things alone. Even perfectly working machines might be disassembled on your workbench just to "see if they can work better."
Sometimes you're more comfortable around machines than people, leading to occasional social awkwardness.
You have a habit of collecting and hoarding spare parts "just in case," making your living space a chaotic maze of components.
Once you're onto a problem, you can't let it go, even at the expense of your own well-being or other priorities.