IDeATe Laser Cutter Guide

The IDeATe fabrication facility includes three Rabbit RL-80-1290 laser cutters. These are extremely useful tools for cutting complex 2D forms from flat plastic and wood stock. The best feature of these tools is the speed with which an idea can be tested: it is possible to conceive of a part, create a 2D drawing, output a DXF, and cut material to make a functional part within minutes.

The laser cuts flat materials such as cardboard, fabric, paper, MDF, plywood, and acrylic. It is however limited to these materials and other commmon materials are unsafe to cut due either to fire or chemical hazard.

Before you begin, please review the IDeATe Laser Cutter Policy. You are responsible for understanding and following all details of the policy. In particular, students must be trained before use and must pass fire safety training before solo use.

Instructions for preparing design files to cut can be found below under Laser Cutter File Formats. The general instructions for operating the cutter can be found under IDeATe Laser Cutter Procedure. The list of materials available for puchase at the Lending desk can be found on the IDeATe Lending Materials Price List.

Process Overview

Laser cutters are intrinsically two-dimensional tools: a focused beam of infrared laser light (e.g. invisible to the human eye) moves on an XY gantry under computer control to trace out curves and lines. The beam is turned on and off to start and end lines during cutting. It may also be used in a raster engraving mode in which it sweeps an area while modulating the beam power very quickly to vary the cut and create an image on the surface.

The fundamental cutting process is melting or burning from the heat resulting from absorbing the energy of the light. An air jet blows downwards into the cut area to help move melted material out of the cut before it resolidifies. The cutter bed can be moved up or down prior to cutting to place the top plane of the flat material at the focal point of the laser.

Laser Cutter File Formats

Please note that the controllers and software were updated Summer 2018, so if you previously used the machine the procedures have changed.

The best format for a cutting plan drawing is DXF with millimeter units and 1:1 scale. The key rule is that every line on the drawing will create a cut in the material, so make sure there are no stray marks, text, annotations, frames, or labels. If marks are unavoidable they will need to be deleted after important. These files are 2D drawings, so can be generated from drawing programs such as Inkscape or Illustrator, 2D CAD programs such as DraftSight, or 3D CAD such as SolidWorks or Rhino by creating the appropriate 2D drawing outputs.

Design Rules

The Rabbit RL-80-1290 has a maximum work area of 1200 x 900 mm (47 x 35 inches). Large pieces may require extra power to cut reliably due to subtle variations in bed height.

The typical kerf in thin acrylic can be 0.005 to 0.010 inches and is slightly tapered, so parts typically are slightly smaller than the designed form, holes are slightly oversize, and the edges are not perfectly square.

Even though the parts are flat, complex 3D structures can be created by using tabs and slots to connect part edges to part faces.

Best Practices

  1. If the laser cutter catches on fire, use the Carbon Dioxide fire extinguisher (CO2 for Class C fire) located nearby. This is very short-range: the nozzle will need to be approximately over the machine.
  2. Small flames in cardboard can usually just be blown out with your breath. Even acrylic can sometimes generate a brief flame. Never use polycarbonate, it will burn.
  3. Thick acrylic cuts can tend to re-fuse, so it is best to remove your parts promptly from the cutter and use a tool to press out all the small pieces. Careful, acrylic is brittle and can crack.
  4. Be sure to wash your hands after handling freshly cut acrylic, it leaves a residue.