Odds of Hanging On
You'll have no trouble hanging on...as long as you keep up with 3D printing, the latest software tools, the newest innovations on time-honored designs, and whatever new technology is needed to make our society run faster, smoother, and more efficiently. That means you'll have to master them as quickly as they come along.
Basically, stay on your toes because you're working in a constantly evolving industry. You're going to have to evolve along with it. That may be tough on the old noggin, but you can ensure you stay valuable as all get out if you keep learning new skills (source).