Here are some further details on:
- The control board, and;
- The stepper motors
The electronics board has this marking:
EJE Electronics Gubbels Engineering
The serial number is
According to this site Xinchejian First Mendel V2 Reprap the board is:
Gen6 Electronics, with AT Mega 644p processor (PCB EJE Electronics, Gubbels Engineering - mendel-parts.com)
It seems to be this board (the serial numbers match):
Information on this board can be found here: Generation 6 Electronics:
Generation 6, or Gen6, can be described as a dedicated, Plug-&-Play, single board solution for FFF/FDM 3D Printers. It is designed to be professionally manufactured, with many small surface mount components, as opposed to Generation 7 which is designed to be printed on a Mendel(among other design goals).
Another major difference with Gen6 electronics is that they use Texas Instruments DRV8811 chips to drive the stepper motors. This means they require firmware modifications from the normal Polulu-based electronics which use Allegro A4983 chips.
It goes on to say:
Benefits of this Design
- These electronics are a single board solution, so you don't need all those cables and one thick sheet and 4 reprap parts less.
However, the thick sheet does add a fair amount of rigidity. @$@#?? the bottom thick sheet (big one) doesnt add
much rigidity, the front one is used for stiffness of the frame, not
the bottom one.
- It has a standard USB connection (USB A>B cable needed)
- It uses micro-stepping (1/8) for quieter operation.
- It is cheaper than for example Makerbot's version of the RepRap Generation 3 electronics.
- It uses small standard Molex connectors for motors, heater, and optos.
- The pcb of the optos are integrated, so you only need the optos on cables with 5way Molex connectors
- on-board USB-RS232 convertor
- Integrated hardware for driving one extruder (stepper, heater and thermistor)
- RS485 bus connector with the possibility to link through the extruder step and dir signals
- Integrated hardware for driving H21LOB or TCST2103 slotted optosensors
- High input voltage range: 12-24Vdc
- Use of standard connectors with easy and clean installation
- Debug LEDs for power, communication and heater output
- Reset button
- Dimensions 110x60mm
- Mounting grid: 100x50mm (4x M3)
- Input voltage 12-24Vdc
- On-board controller: ATmega 644p (Atmel Corp.)
- RS485 connector: RJ45
- Heat output: MOSFET output, 4A
- Thermistors input: 100K thermistor
There is a lot more information on that page, including information about the power supply, USB, End stops, Heaters, Motors, Firmware, etc. I suggest that you read it fully, in order to understand the board's functionality.
The stepper's model number can be seen here:
The stepper's model number is
which is a NEMA-17 High Torque Hybrid Stepper Motor, with these specifications:
- Step angle: 1.8°
- Number of phase: 2
- Rated voltage: 2.8 V
- Rated current: 1.68 A
- Holding torque: 4.4 kg/cm
This would be, at least, part of the datasheet:
Here are a couple of links, should you need replacements (~€17):
This stepper motor is also listed on the RepRapWiki - NEMA 17 page:
Model Holding Torque Rated voltage Shaft Step angle Motor length Rated current Inductance
SY42STH47-1684B 43.1 N·cm 2.8 V Ø 5 mm double 1.8° 48 mm n/a n/a