Hey Paul
I’m using a Ender 3 Pro. For CAD software I use OnShape. It web based and free. I have done a number of this for my hobby’s and when it gets complicated I know a CAD guy that helps me out (aka my son)
There is a bunch of people 3D printing RC planes in sections. There is now a light weight PLA that they use.
The wheels you probably saw were probably printed using TPU. It’s a soft type of PLA. ABS can be used for harder structures but I’m a little hesitant due to the fumes of ABS. The printer is in my garage and don’t want to stink up the house. 🤣
It’s all pretty simple to use. I have printed handles, motor mounts for electrics, battery caps for my LiPos. Battery/ESC mounts, and my last big print was a cowl for my Vector. It came out just about as light as the balsa cowl. But I needed a little nose weight. 👍🏼