| Logic |
Arduino MEGA compatible Atmega2560 and Atmega32u2 processors are compatible with all RAMPS class firmwares |
| Crystals for both usb and mcu (timing accurate to 10ppm) |
| 4 Thermistor jacks |
| All extra pins broken out on both processors (allows using the 32u2 for LUFA AVR programmer, etc.) |
| 2 channel SDRAMPS compatible SPI breakout |
| Motor Drivers |
5 A4982 1/8th microsteps motor drivers with 1,1/2,1/4,1/16 as options (2 connectors on Z for Prusa Mendel) |
| Digital Trimpot for stepper current control |
| Current limit on driver IC VCC to prevent permanent latchup |
| Microstep mode configured by MCU through firmware (no jumpers needed) |
| Test points for driver control signals |
| Step and Direction pins are on their own ports for synchronous movement capability |
| Extra driver ports broke out for up to 3 additional drivers (some of the motor extension pins are shared with max endstop and a pin allocated for SPI-SS extensions) |
| PWM DC outputs (Extruders, Fans, Etc.) |
6 outputs |
| Low resistance mosfets for cool running |
| Indicator led for each channel |
| Power |
Three independent power rails |
| Heated Bed, 15A 12-35V |
| Extruders + fans and logic, 5A 12-35V (fuse can be exchanged for up to 10A capacity) |
| Motors, 5A 12-28V (fuse can be exchanged for up to 10A capacity) |
| Built in SMPS for 5V generation from 10V-26V Vin |
| PCB |
4 layer |
| 2oz copper on all layers |
| High quality, High temperature FR4-TG130 PCB |
| Gold ENIG finishing |
| Fuses |
3 user replaceable NANO2 fuses |
| 0448005.MR |
| F2: motors and on-board power supply |
| F3: extruder heater + fan outputs and logic |
| F4: automotive-type 15A ATO bladed fuse to for the heated bed |