This board is based off MiniRambo, the Arduino MEGA design, and the work of RepRap community. It has 4 Trinamic TMC2130 stepper drivers and 4 mosfet switched outputs.
Differences from MiniRambo
- 4 tmc2130 1/256 microstepping drivers vs. 4 a4982 1/16 microstepping drivers
- Sensorless homing vs. No sensorless homing (Requires advanced tuning)
- 2 mechanical endstop inputs (2pin) + ZProbe (4pin) vs. 6 optical endstop inputs
- SPI control of motor current vs. PWM control of stepper current
- FANS are powered by 5 Volt rail and have tachometer feedback using a 3pin connector vs. 12-24V powered with no feedback.
- Max motor current per driver is RMS 940mAh vs. RMS 1.4A
Power must be connected to the Primary Power input for the board to operate. The USB connection is isolated from the rest of the board and cannot be a power source.
- Arduino MEGA compatible Atmega2560 and Atmega32u2 processors are compatible with all RAMPS class firmware
- Crystals for both usb and mcu (timing accurate to 10ppm)
- 3 Thermistor jacks + 4th Thermistor circuit on ZProbe.
- 4 Trinamic TMC2130 1/256th microstep motor drivers(2 connectors on Z for Prusa Mendel and other dual Z printer designs)
- SPI Control of stepper current instead of PWM.
- Microstep mode configured by MCU through firmware (SPI, no jumpers needed)
PWM DC outputs (Extruders, Fans, Etc.)
- 4 outputs (1 Extruder, 1 BED, 2 low power (fan,etc)
- Low resistance mosfets for cool running
- Indicator led for each channel
- FANS have 3pin fan connector.
- FANS have 5V instead of 12-24V power source.
- FAN connectors have tachometer feedback pin to the MCU to measure fan speed in capable firmware.
- 2 power input rails
- Heated Bed, 15A 12-24V (15A dedicated fuse)
- Primary Power 10A 12-24V: Motors, Logic & Fans (5A dedicated fuse) + Extruder (5A dedicated fuse)
- Built in SMPS for 5V generation from the Motors, Logic & Fans rail
- Provides 5V power to FANS
- 6 layer
- 2oz copper on all layers
- High quality, High temperature FR4-TG130 PCB
- Gold ENIG finishing
- 4-pin motor,zprobe plug - Molex 5057-9404
- 3-pin fan plug - Molex 5057-9403
- 2-pin thermistor, mech. endstop plug - Molex 5057-9402
There are 3 user replaceable ATO fuses (the type found in many automotives).
- F1 5A supplies the motors + logic & fans .
- F2 5A supplies the extruder heater.
- F3 15A supplies the heated bed output.
Just like Rambo ArduinoAddons need to be installed to make use of all the pins. Not installing ArduinoAddons can result in only partially working features. ArduinoAddons can be installed manually or by the new board manager third party url feature. Rambo_firmware#Arduino_184.108.40.206B_Board_Manager_Plugin
Windows 10, Linux, Mac have built in CDC driver.
- Boards sourced from UltiMachine can reuse the same Windows CDC driver as the RAMBo USB driver.
- Boards sourced from Prusa3D use their driver.
1.1a Revision Summary
- Added 2Mb serial flash
- Added voltage translators for serial flash
- Added tri-state buffer to block 3.3V MISO on the SD Card from the 5V MISO bus
- Added barrel-relief to bottom side of thermal vias for TMC2130, FETs and SMPS
- Added 3.3V LDO for serial flash
This is a generic troubleshooting guide. These steps may vary depending on manufacturer configuration. Contact your supplier if these steps do not help.
- Cannot connect with 3D printing control software
- All Heater and Fan LEDs stay lit when board is powered.
- Check that the power source is not plugged into the Heater outputs.