Some years back it really made sense to build your own 3D printer. You could get good results and save some money. I certainly couldn't have afforded an original Prusa or a Ultimaker back then.
This is not the case anymore.

In this video I mentioned a couple of video series from the past:

Thomas Sanladerers "Building the cheapest possible Prusa i3 MK2 clone" and Tech2C with his "Hypercube". Tech2C did some interesting stuff on that printer like using carbon rods and bushings (does that sound familiar?)

From the archive:
Thomas Sanladerer
   • Building the cheapest possible Prusa ...  

Tech2C
   • New 3D Printer Parts