3D Printer da Vinci Junior – Marlin / MKS 1.4 Board Modification

Updated (29.08.2018): Updated some things and the firmware

The da Vinci Junior 3D Printer is small, light, has a closed case, LED Lights, is easy to use, and you can get it for 275-349€. For me the printing results are very good, but you can not use any Filament because of the NFC Chip protection. There are some tutorials for da Vinci modifications, but they all are working with the basic Marlin Firmware, that not has a 100% logical menu structure, and some things are missing completely.

With my MKS Gen 1.4 Modification you have nearly the same functions like the original da Vinci Jr Firmware (Load Filament, Unload Filament, Clean Noozle, ADJ Z Offset, …). But also some new functions like a Stepper Driver Selection (A4988, DRV8825, TMC2100) or the Driver Module Temperature Measurement on the Info Screen, also “Nozzle PID Autotune” in the “Settings”. And… I think a really easy and fast way to modify your da Vinci Jr.






What do you need?



  • Create flat 130cm Noozle cable with 10 Wires and two adapters with resistors (Case Light, Endpoint Sensors)
  • Remove the da Vinci Junior mainboard and the flat Noozle cable
  • Insert the MKS 1.4 Board, adapters and dupont wires
  • Use the new flat Noozle cable to connect the Noozle and MKS Board
  • Modify the Display Case with the LCD2004 Module
  • Upload the Arduino Firmware into the MKS 1.4 Board (Download down below)
  • Install the Driver boards and adjust the Driver voltage (A4988 0.5V, DRV8825 0.6V, TMC2100 0.6V)
  • Power up the da Vinci Junior and select the used DRIVER MODULE in the “Settings” Menu
  • Adjust Noozle Home Position in the “Settings” Menu



Here are the connection overviews of the two boards:




Every little mistake will burn the Board, the Drivers and other elements. So, take care of  that what you are doing. DO NOT SWITCH ON THE BOARD without connected STEPPER MOTORS if the DRIVER Modules are plugged in! So, please check also the connected Stepper Motor cables and check THE DIRECTION you plugged in the Driver modules!

The Hotend need more current as one wire can handle. One single wire will be very hot and is dangerous! This is the reason why I use  2 x 3 Wires for the Hotend!


Motor Stepper Drivers:

  A4988 DRV8825 TMC2100
Board Voltage 12V  12V 24V with E3D V6 Extruder
Drivers Ref. Voltage 0.5V  0.6V ~0.6V
Temperature < 50°C < 50°C  < 60°C (100 mm/s)
Noise very noisy  noisy less noisy
Mode CFG1->GND


Left Picture: this is the TCM2100 Driver. Adjust the Vref Voltage to ~0.6V: 

upper red box: Potentiometer to adjust the Vref
lower red box: Pin to measure the Vref


I’m using the CFG1->GND setting, because of higher speed without step losses. If you have step losses, then you have to increase the Vref a little bit. By the way, the tension spring of the extruder is too strong, with soft filament it is squeezed too much and blocks the hot end very quickly. The same goes for printing too fast at too low temperature.


Used Power Supply for the MKS Gen 1.4 Board: LEIKE 24V 4A

To use the Light and the Fans with 24V you can use a StepDown Module, then you can regulate the 24V to 12V:




Some optimizations/hints:

1. The spring of the feeder is to strong. Soft Filament is squeezed (no longer round) and the hot end will become clogged. So you have to pull out some tension. Take a screwdriver, put it in the spring and turn it from side to side. Now you can see some more distance between, and the spring is losing strength. Now test the filament by clamping it and moving it back and forth. It must remain round.


2. When the feeder clicks during printing, then you have to increase the temperature a little bit (~20-30°C). Some soft filaments are working fine with 195°C, but some harder filament need 220-230°C. The faster you print, the hotter it has to be. But also massive retraction can clog the hot end. So you have to tune the retraction values a little bit.

3. When the motors behave strangely wild (twitching movements), then the motor cables are not fully connected. I’ve used some dupont jumper wires, but later it turned out (after 1 1/2 years), that I have cable problems with the motors. Then I soldered a connector directly and everything was fine again.

4. When you have step loses (layer displacements), then you have to increase the stepper driver current (Vref).

5. When the motors or stepper drivers are to hot, then you have to decrease the stepper driver current (Vref)

6. As you can see above, now I use another extruder, the E3D V6 (24V), and I use 24V with the MKS Gen 1.4 board, as well a step-down board from 24V to 12V for the fans and the light. Tested with 100 mm/s (Cura) and is working fine. But, with some Filaments I use the old XYZ Printing HotEnd, because the E3D V6 clogged very fast (while retracking).



3w to G-Code Converter for MacOS (for complicated prints I’m using Cura now):

This is my da Vinci 3w to G-Code Converter. With this tool you can control also some G-Code values. I’m using the XYZWare Version 2.1.4 Software, because it is newer, but not the newest with the annoying “Internet always On” feature.


Other Software:

If you are using another 3D Printing Software, then after “G28” you have to use as 2nd command: “G1 X0 Y0 Z12” to set the Nozzle to the start position. If you are not doing this the Nozzle will jump over the left front bed corner. 






This is my new Filament holder. He is stronger than the old one (brocken a few times). You can download the STL file down below, together with all other files for this project (Firmware, …).