Extramaker 3d Printer

Here are the goals of my printer design:

Build Area 200x200x215
120 mm/s speed (at least)
Two sizes of extruded 2020 (300mm and 200mm)
Rigid Frame
Easy to assemble
Easily scalable
Small Bill of materials
Single Belt
V6 extruder

Here is a basic parts list:

Ramps kit with 5x Nema17 and Smart Discount Full Graphic Controller
60cm cable for the Smart Discount Full Graphic Controller
8 x 8mm x 300mm Length Smooth Rod
2 x 8mm x 300mm Length Leadscrews with nut
2 x 5mm to 8mm flex coupling
12 x 300mm 2020 T-slot or V-slot (Will need to be Tapped to M6 on each end)
4 x 200mm 2020 T-slot or V-slot (Will need to be Tapped to M6 on each end)
16 x LM8UU bearings
2 x 608zz bearings
Bowden extruder Kit (right hand)
MK2a heated bed with alum build surface (can be use glass, Z endstops must be used)
E3D V6 or V6 Lite 12v with bowden addon
3ft of PTFE Tubing
12v 30a Power supply