15. Mechanical design


  • group assignment
    • design a machine that includes mechanism+actuation+automation
    • build the mechanical parts and operate it manually
    • document the group project and your individual contribution

For the two machines week, we want to make a Syringe pump end-effector for the 4xiDraw.

All detailed information can be found on our group page.

We divided the work into sub-groups, one focusing on the adaptation of the 4xiDraw project and the other on the syringe pump.

I decided to work on the 4xiDraw, as it is a quite new subject for me!


Studying the 4xiDraw

My first job was to study the 4xiDraw principles…

Motor control

In week12, I’ve looked at the functioning of stepper motors.

Core XY

How to build a two-axis drawing machine, or a two-axis CNC stage by using two stepper motors? CoreXY / H-bot approaches are the solution, as explained here * Rotating both motors in the same direction results in horizontal motion.
* Rotating both motors in opposite directions results in vertical motion.

GRBL and G-code

GRBL is an open source, embedded, high performance g-code-parser and CNC milling controller written in optimized C that will run on a straight Arduino (ATmega328P based…)

G-code (also RS-274), is the common name for the most widely used numerical control (NC) programming language, whose instructions, provided to a machine controller that tells the motors where to move, how fast to move, and what path to follow…

3D print

I’ve 3D printed some of the pieces, namely * both End Y belt holders * the pen carriage with rack and pinion * the servo holder


I wanted to start the assembly of the machine, but we are still waiting for pieces to be delivered to start the assembly… Please come back…

So, we used the machine of last year with the adaptation made by Axel.


I wrote the 4xiDraw documentation on the group page.