Quick Start Guide

A brief guide introducing the basics of laser cutting and the Fab Lab to start you off in digital fabrication and help you level up your design.

Submission and Machine

Checklist

• Rhinoceros 3D is installed

• Download Fab Lab Laser Cutting Template

• All goemetry is linework for CUT and ETCH

• CUT line spacing adheres to material specific parameters (see Parameters).

• All geometry is hatching for RASTER

• All linework is on correct layers (CUT, ETCH, RASTER)

• All linework is set to "By Layer" for print colour, width, linetype

• Explode Text (command: Explode)

• Remove Duplicate Lines (command: SelDup > Delete)

• Ungroup all geometry (command: Ungroup)

• Specify material, name and student ID number in file

Download the Template File

Video Tutorials

Laser Cutting YouTube Playlist

Parameters

Machine Parameters

Material Standard Size: 700 x 1000mm

Material Maximum Size: 900 x 1200mm.

Materials Safety Data Sheet: Students can bring material from other suppliers, but it must be accompanied by a Material Safety Data Sheet (MSDS) which can be obtained from the material supplier.

Line Colours and Types

• CUT: Black (RGB: 0,0,0) Vector line

• ETCH: Red (RGB: 255,0,0) Vector line

• RASTER: Blue (RGB: 0, 0, 255) Hatch

CUT, ETCH, RASTER

Laser cut example: Truss structures are cut from 1.8mm boxboard

Minimum geometry size and bridges

The bed of the laser cutter consists of a metal tray with a 10x10mm grid of gaps; upon which material sheets are laid. Therefore any geometry with a shortest side ~10mmm or shorter in length will likely fall from through the laser cutter bed and will be lost.

The geometry on the left is small enough to fall through the laser cutter bed

There are two solutions to this:

A) Increase the size of the geometry so that it is large enough to not fall through the laser cutter bed.

B) Include ‘bridges’ or breaks in the linework of small geometry so that it stays attached to the material sheet instead of falling through. These pieces can then be cut out by hand from the sheet.

The gaps in linework keep the small pieces attached to the sheet instead of falling through

1. Bridges can easily be added to your geometry using the “Break” command in Rhino.

2. Or, if you are familiar with Grasshopper, use this simple script to quickly apply bridges to closed curves:

Bridge maker (MSD FabLab).gh

19KB

Open

Set 1: Set Curves

A) Open 'Bridge maker.gh' with the Laser Cutting Template. Select all the relevant CUT lines, and 'Set Multiple Curves'.

Step 2: Control Variables (No. & Width of Bridges)

B) Using the 'number slider', select how many bridges you want to generate, and the width of the bridges.

Step 3: Bake new curves

C) Right click on the 'Curves to Bake' container to 'Bake' new curves.

Step 3: Ensure you 'bake' into the CUT layer

D) Choose the 'CUT' layer to 'Bake' new curves into the Laser Cutting Template. Ensure to delete the original CUT lines.

1. You can also add an etch line along the bridges to provide a guideline of where to cut out the pieces by hand.

The etch lines provide a guide for where to cut out the pieces by hand

Minimum cut line spacing

Cut line spacing refers to the minimum allowable distance between parallel lines when laser cutting.

As laser cutting requires heat (the laser) materials behave differently when being laser cut. Some materials, such as plastics will distort when too much heat is introduced. The build up of heat can also lead to fires.

The following is a list of materials and their respective MINIMUM distances between CUT lines. These distances do not apply for etching, only CUT operations.

**Please note: These settings are a BETA version and may change as we learn more. Refer back to this list before each Laser Cutting submission. Failure to adhere to these minimums will result in job cancellation.**

Material	Material Thickness	Minimum cut line spacing
MDF	3mm	3mm
Boxboard	3mm	2mm
"	1.8mm	1mm
"	1mm	1mm
Lauan Plywood	2.7mm	2.5mm
Poplar Plywood	3mm	3mm
Perspex (Acrylic)	3mm	4mm
"	2mm	3mm
Polypropylene	0.6mm	2mm
Mountboard	1.5mm	1mm
Optix Card	300gsm	0.5mm
Ivory Card	290gsm	0.5

Costs

Cost: $1.00 per minute + material costs

Fab Lab Materials List

Reducing Cost

3 MINUTES

NOTES

The two important things to reduce the cost of laser cutting is the amount of material you use and the time it takes to process.

Tips include:

• Efficient nesting of linework onto your sheets to minimise the number of sheets you need.

• Sharing cut edges to reduce the amount of material used and minimise processing time.

• Reducing the density of your etching and rastering for visible resolution and reduce processing time.

• Reuse sheets from previous jobs that still have usable material.

Reducing Material Use

Nesting Geometries Efficiently

Objects that sit outside the internal boundary risk not being read by the laser cutter and may not be cut. Objects sharing the same edge will produce a more accurate cut and finish. It will also save cutting time and reduce material wastage. Unless objects are using the same cut or score line, space objects at least 5mm apart. Jobs which are spread across an excessive number of sheets will not be accepted.

1. Use the [Move] and [Rotate]commands, or use the Gumball, to nest your objects closer together.

2. Move the objects towards the top left corner.

3. Ensure the objects do not extend out of the internal boundary.

4. Have objects share edges as much as possible; straight lines can be aligned to save material wastage and to reduce cutting time.

   1. Avoid overlapping lines. An easy way to avoid this is to select your overlapping objects and use the[Make2D]command and [SelDup] to select and delete any duplicate lines.

Poor Nesting (Left) and Better Nesting (Right)

Poor Nesting (Left) and Better Nesting (Right)

Selecting Material Size

Check the Fab Lab Material List to see if your material can be cut on smaller sheets (i.e. 600x600mm instead of 900x600mm). If your chosen material is available on smaller sheets, use [Scale1D] to change the size of your material.

Poor Material Size Selection (Left) and Better Material Size Selection (Right)

Selecting Material Thickness

Some materials come in multiple different thicknesses; where possible, try using thinner sheets.

Reducing Cutting Time

The quicker a job is to cut, the less it will cost for cutting time. To reduce cutting times, try reducing the amount of lines/curves a Job has.

Reducing Lines

• Avoid lines of less than 1mm.

Reducing Hatching

• Hatching can be very time-consuming; limit hatching where possible or replace with Etch outlines instead.

SUBMIT

Once you are confident your file is ready, please submit job here:

Job Submission

If you would like to speak to one of our technicians about a specific job or project, please book a consultation here:

Book a Consultation