So if I have a build in mind which do i choose. Threaded rod drive or belts? Which is more accurate? Which is smoother? Etc....
It depends on the application. Screws will give you higher torque, better precision and smother travel but it can be difficult to find long lengths. Belts are usually faster and cheaper but can suffer in accuracy and need to be tightened as they stretch. Maybe share what your build idea is for better advice.
Threaded rods are much stiffer than belts and allow much better accuracy and deeper cuts. They also require very little attention and maintenance. Belts on the other hand are usually much faster, cheaper and more convenient to assemble. Accuracy depends heavily on correct belt tension and shallow cuts -> frequent checks required. Threaded rod should at least be ACME thread or if you can spend some money: ball screw. Do not use threaded rods from the hardware store - they are very inaccurate and won't last more than just a few hours. So basically: if your focus is to safe money / just have some fun and gain first experiences go for the belts - if you need precision I'd prefer good screws (and a generally rigid machine design)
You can get 6 foot lengths of acme rods shipped from McMaster Carr if you need something longer than a meter. However, you will need larger diameter threaded rod if you go big.
