Plasma cutters

From
Project: Plasma cutters
Designers: Timothy Schmidt
Parts: Laser cutters, Linear bearings, controllers, Motors, Linear bearing assemblies
Techniques: Tri joints

Introduction

Plasma cutting is a process that cuts through electrically conductive materials by means of an accelerated jet of hot plasma. Typical materials cut with a plasma torch include steel, stainless steel, aluminum, brass and copper, although other conductive metals may be cut as well. Plasma cutting is often used in fabrication shops, automotive repair and restoration, industrial construction, and salvage and scrapping operations. Due to the high speed and precision cuts combined with low cost, plasma cutting sees widespread use from large-scale industrial CNC applications down to small hobbyist shops.

Challenges

Replimat firmware must be modified to perform a number of additional steps required for plasma cutting. Circuits must be added to Controllers for voltage and capacitance sensing as well as plasma firing and isolated for protection from high voltage.

Approaches

Electronics

  • Selectable 50:1 or 100:1 voltage divider connected to ADC connected to optical isolator
  • Capacitive sensing connected to optical isolator
  • Relay or SSR for firing plasma

Firmware

Github: Buildlog Lasercutter Marlin

Software

Laserweb

References