3D printers should become much faster, and more precise.

Belts are slightly elastic and at high speed with high jerk they will and do stretch momentarily and create small artifacts in the print product.

We can get an extremely fast and precise 3d printer by replacing belt drive with spline drive:
spline-drive.jpg

The axis gears should be double helical so that there is no vibration from the gears.

The rest of the design is left to the reader