This was a little project that I am going to continue working on. I wanted to try out a follow focus on my camera but the price of them really isn't affordable for me, so I wondered if it would be possible to make a fully 3d printed rail system as well as the follow focus. Turns out it works pretty well, for light cameras it works best. I am unsure of what cameras will work on this but I know my Nikon D5500 works because that's what's pictured. The lens ring is for my 18-70mm lens with an outside diameter of 73mm if that's any use to anyone. It's not the best made thing in the world but it works at least. The two bevelled gears inside the "gearbox" should be at a 90 degree angle to each other and filling the box with vaseline as lubrication will make them spin quieter and smoother.

I AM NOT RESPONSIBLE FOR YOUR CAMERA FALLING OFF AND BREAKING. This system is entirely plastic so I really wouldn't trust an expensive camera on it. A mirrorless camera/light dslr should work fine but do your own tests in terms of strength, bad layer adhesion and other factors could make this very weak and unusable so make sure your printer settings are tuned in properly. I'm fairly new to Fusion 360 so it's as good as I can make it at this current time. Studying doesn't allow much time for things like this so I will work on improving it when I can.

Sidenote: If you want to replace parts with metal versions it will make it a lot stronger, specifically the rods. Hope this comes in use for someone. Also for anyone wanting to add their own attachments to the rods they are 60mm apart, centre to centre.