Ya, as a mechanical engineer with some experience in additive manufacturing (AM), I'll chime in that there are some aircraft manufacturers who use AM for production. However, without knowing the material or specific AM process I can't give you much feedback. I can definitely say that there is a reason why bike manufacturers do not use AM for making forks though . I know of a few pieces (transmission case) that are rather large and carry some load, but I can't think off the top of my head of hearing about any structural suspension pieces that are produced using AM. There might be some precedence, I'm by no means an expert (my expertise is more with structural dynamics and networked sensor arrays), but it doesn't seem like an application that AM would be the best choice. Also, if you don't have any experience with CAD/CAE, and designing a load bearing structural component then you probably should not even be attempting a project like this. Properly designing any structural piece (e.g. front fork) requires material knowledge, structural design to account for both loadings and fatigue limits, and the experience with CAD/CAE software.

It's not just as simple as drawing a fork in a computer program and printing it out.