CNC Drawing machine made by TechnoFabrique

We decided to build a drawing machine after we bought Nema 17 step motors. We wanted to make a drawing machine that use the less we need to buy, To control one axe, we only need a Nema 17 that pull a wire to move in and an elastic pull out.

Project Overview

"CNC-Logic" is a rigorous implementation of Open-Loop Mechatronic Orchestration and Asynchronous Motion Forensics. By utilizing two manual joysticks instead of a standard G-code streaming PC, this project explores the direct synthesis of analog-to-digital motion vectors. The system features a 3-axis NEMA 17 kinematic array, where horizontal $(X, Y)$ and vertical $(\text{Pen-Z})$ movements are controlled via deterministic voltage-threshold forensics. The build emphasizes structural ingenuity, using custom-fabricated limit switches to provide fail-safe operational diagnostics.

We didn't want to control it with a computer, but rather with joysticks, to be efficient only with alimentation. The right joystick allows movement on axes X and Y, meaning that we can draw with it. The left joystick is used to position the pen.

Technical Deep-Dive

• Stepper-Driver & Current-Chopping Forensics:
  • The A4988 Logic-Engine Diagnostics: Each NEMA 17 motor is driven by an A4988 IC. Forensics involve configuring the "Step" and "Direction" pins to translate Arduino logic-pulses into discrete magnetic steps. The diagnostics focus on Current-Limit Heuristics, tuned to prevent thermal-runaway while maintaining high holding-torque for the pen-actuators.
  • Bipolar Microstepping Harmonics: The system executes high-resolution motion by pulsing the A4988's internal translator. Forensics into the half-step or micro-step modes allow for smooth, low-vibration drawing-paths, effectively dampening the mechanical resonance associated with high-current stepper harmonics.
• Joystick-to-Cartesian Mapping Heuristics:
  • The Analog-to-Pulse Orchestration: The joysticks provide a continuous voltage gradient $(0-5\text{V})$. Forensics involve mapping the deviation from the central null-point $(\approx 2.5\text{V})$ to a dynamic stepDelay. As the user pushes the joystick further, the pulse-frequency $(\omega)$ increases, resulting in high-velocity translational movement diagnostics.
  • Axis-Arbitration Harmonics: The left joystick is dedicated to the Z-axis $(\text{Pen-Lift})$, while the right joystick manages the XY-plane. This orchestration ensures that drawing operations can be performed with sub-millisecond tactile precision without requiring complex CAM software pipelines.

Engineering & Implementation

• Limit-Switch & Fail-Safe Diagnostics:
  • DIY Contact-Forensics: To prevent mechatronic stall-out, the build utilizes a custom "Aluminum-on-Cardboard" limit switch design. Forensics involve polling these contacts as digital pull-up triggers; when a strike occurs, the logic-engine immediately halts the pulse-stream for that axis.
  • Visual Diagnostic Strobe: 6 LEDs provide real-time photonic confirmation of the "End-of-Stroke" status. Each LED corresponds to a positive or negative axis limit, providing a professional-grade HMI for signal-path verification.

We can see 6 LEDs, which are used to inform us that an end of stroke switch is activated. Here's how we made those end of stroke with aluminum and carton.

• Structural Kinetic Stability:
  • The kinetic link uses high-tension wires and elastic-return heuristics for axis recovery. Forensics into the cable-tensioning ensure that the NEMA 17 torque is efficiently converted into linear displacement without belt-slip or parasitic mechanical hysteresis.

Now there is a video of the project :

Conclusion

CNC-Logic represents the pinnacle of Manual CNC Engineering. By mastering Stepper-Driver Forensics and Analog-to-Motion Orchestration, TechnoFabrique has delivered a robust, computer-free drawing platform that showcases the power of direct human-in-the-loop diagnostic control.

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Vector Vision: Mastering mechatronic telemetry through stepper forensics.

If you liked, please come watch our website :http://technofabrique.wixsite.com/techno-fabrik/projet-cnc