ME360 CNC Pyrography
Teams were tasked with the design and construction of a 2.5 DOF system that performed a task of their choice.
The device comprised the structure and motion elements (stepper and servo motors, pulleys, linear guides and belts).
Minimum work volume: 2.5" x 2.5" x 2.5"
System should be small and light enough to be easily carried in a backpack
It may be partially or completely disassembled for transport
If it disassembles for transport, It must be able to be assembled in under 10 minutes
The following components were provided:
25mm x 25 mm aluminum extrusion
NEMA 17 stepper motors
GT2 belt & pulleys
MKS v1.6 board
Access to 3D printing facilities
Our team chose to develop a CNC pyrography machine. We settled on a CoreXY motion system, and developed a tool that used a high-voltage arc and compressed air to burn a substrate (similar to a plasma torch).
The main benefit of a CoreXY system is that it reduces the inertia of a mechanical system by relocating much of the moving mass of a typical serial linear motion system to static locations in the structure.
The aluminum extrusion was purchased from 8020.net, which provides CAD models of their products. These extrusion models, along with hardware and fastener models downloaded from McMaster Carr, provided the basis for a SOLIDWORKS assembly.
The basis for the effector was the article "Arc Lighter Becomes Plasma Pyrography Pen" by Dan Maloney on Hackaday. It shows that a high-voltage arc can be used to burn wood, rather than a more conventional approach that uses heat.
We were provided with an MKS v1.6 control board (Based on an Arduino Mega). We chose to flash it with a modified version of Marlin, a popular 3D printing firmware. The main benefit of using this firmware was that it allows for a high degree of customization for varying machines with minimal programming knowledge. As such, we could focus on the electro-mechanical design of the system. Control of the system was accomplished via g-code.
Overall, this project served as a great hands-on learning activity. We learned a lot about machining tolerances, design for additive manufacturing, troubleshooting for both mechanical and electronic compontents, and CoreXY geometric constraints.