Large 3D Printer

Large volume 3D printer Build volume of 300x300x400mm Overall dimensions: X520-Y620-Z640 Built mainly with aluminum 20x20 and printed parts with a optimized and lightweight design. The extruder is an MK8. For a future design I would like to use a "Bowden" type. The Y carriage with hot bed could be optimized more its weight by cutting the aluminum sheet that holds the hot bed and using a 3mm glass, although it works well for me as it is. The engine pap of the Y carriage could be one of 1.7 A although I have changed it to one of 2 A to improve the dynamics. All the commercial elements except for the aluminum profiles and the chrome bars I have bought them on Aliexpress. BOM: 2 Screw and nut THSL-500-8Dx1 Aluminum Profile 20x20 Type I Slot 5mm - 2x530; 3x360; 2x580 50 Nut Profile 5 tipo-I [M4] 8 Linear Bearing LM8UU 8x15x24 4 Linear Bearing LM10UU 10x19x29 2 Chrome Bars 8mm - L445mm 2 Chrome Bars 8mm - L530mm 2 Chrome Bars 10mm - L530mm 2 tubes of diameter 9.8 x 595mm 2 Coupling 5x8 1 Pulley GT2 6mm 20 Dientes eje 5mm 1 Free Pulley GT2 6mm 20 Dientes eje 5mm 1 M Belt GT2 6mm 1 Pulley GT2 10mm 16 Dientes eje 5mm 1 Free Pulley GT2 10mm 20 Dientes eje 5mm 1 M Belt GT2 10mm 1 GT2 Timing Belt Fixing 9x40mm 1 steel shaft 5mm L18mm 1 steel shaft 5mm L19.5mm 1 Hot Bed Support Aluminium 324x324x3 1 Hot Bed 328x328x3 1 Hot Bed Glass 310x328x4 4 Rubber feet 1 Extruder MK8 con Motor Nema 17 1.7A 1 Motor Nema 17 2A 59Ncm (eje Y) 1 Motor Nema 17 1.7A (eje X) 2 Motor Nema 17 0.6 A (eje Z) 4 Driver DRV8825 1 Ramps 1.4 Shield 1 Arduino Mega 1 RepRap LCD full graphic smart controller 1 Power Supply 24V 20A 1 Fan 80mm 12v 1 Step Down Converter 24v to 12v / 9A 300W 1 Fan 40mm 12v 1 Relay Socket 12Volt 40A 1 Switch 250 v 15 A 3 Limit switches Wires 1 Cable Chain 10x20mm L0.5m 1 Cable Chain 10x10mm L0.5m M3 Screw Leveling Spring Bolts M4 different lengths Nuts M4 Bolts M3 different lengths Nuts M3 PLA Filament 1 kg Edit 20-04-2018: The file Frame_Hot_Bed_mod.stl is added. It is the aluminum