LaserLab 101

How It Works

• • Laser tube in the back

  • 90W Carbon Dioxide Laser

  • Fires out the left side, 1 cm thick beam

  • Bounces off mirrors and hits lens to focus the beam. 

  • When the laser is in focus, the beam is .25mm to .5mm wide, depending on material thickness and settings.

  • Focus height

  • Make sure lid is closed - Laser will fire if lid is open (super dangerous!!)

Laser Cutter Fees

• • Drop-In Rate: $2/cutting minute 

  • Member rate: $1.50/cutting minute

Materials

• • Wood

    • Up to 3/8“

    • Can cut 3/4“, but very slowly

    • Baltic birch plywood is highly recommended over other plywoods

  • Acrylic

    • Up to 3/8"

    • Mirrored acrylic MUST be cut with the mirror side facing down

  • Fabric & Leather

  • Paper Products

    • Cardboard

    • Paper ** do not cut stacks of paper. Air can get in between the sheets and cause a fire.

  • Metal

    • Etch, using special spray

  • Ceramics, Glass

    • Etching

  • NO VINYL or PVC, ever. A credit card is PVC. A vinyl record is vinyl. Super bad for you and the machine

Different Laser Cuts

• • Cut

    • Laser cuts through the material following a vector line

  • Trace

    • Laser traces, leaving a mark on the material along a vector line

  • Raster

    • Laser engraves an image into the material in a black/ white (engrave/raw) method

  • Raster with Dither

    • Laser engraves an image into the material in a grey scale (engrave/partially engrave/raw) method

  • Raster with higher dpi

    • Laser engraves an image into the material with a higher precision.

Safety Considerations

• • Power button

  • Before cutting make sure the fan is on

  • NEVER LEAVE THE LASER CUTTER when it is on.

  • Clean up! Users are responsible for clean up after themselves

  • Water spray

  • Fire extinguisher

  • If you're ever unsure of anything, ask staff

NEVER CUT THESE MATERIALS

WARNING: Because many plastics are dangerous to cut, it is important to know what kind you are planning to use. Make has a How-To for identifying unknown plastics with a simple process..

How It Breaks

• • Running the floor up into the laser head (super bad)

  • Running the laser head into the edges (less bad), need to re-home after that occurs

  • If you ever hear a loud noise, unwanted laser/bed movement - HIT THE RED STOP BUTTON

  • Support systems not turned on - Laser tube will break ($1250 fine)

Support Systems

• Exhaust switch by large laser cutter must be ON

  • pulls out smoke and fumes

• Industrial Chiller must be ON

  • cooling -- laser tube gets hot, will break if too hot ($1250 fine)

• Air compressor is ON

  • keeps lens clear -- blows out small fires -- stokes embers 

***Both chiller and air compressor should be connected to the same power bar***

Different Laser Techniques

• • Jigging

    • To engrave or cut into something perfectly, the way you set your zeros

  • Different Bases

    • The honeycomb is great for small pieces. It can heat up from the laser and scorch the bottom of your piece.

    • The metal grate (underneath the honeycomb) has fewer bars, and scorchs your piece less.

    • A wooden base, underneath your piece, will reduce scorching

  • Taping your piece (masking tape)

    • Taping your piece will remove scorching wherever you cut

    • Downside: you will have to remove it afterwards and depending on your cut, could be very tedious

  • Vector Current

    • Vector current is always set at 100%, and is a multiplier added to vector cuts. If you need to reduce the laser power lower than 1, adjust this multiplier.

  • Cutting out of focus

    • With the laser in focus, the line beam is .25 to .5 mm wide depending on material thickness and settings.  It will leave a trace the thinnest possible, depending on how the material reacts

    • Taking the laser out of focus, the width of the beam will be larger if you want a thicker trace

Machine Set Up

Lay and secure material on the bed, move laser head away, and how to align (z -direction, and horizontal zero)

Software

1) Design from any vector based software

2)  Initial Laser Set-up

• • Open from browser Window

  • Make sure Laser is turned on - it will connect automatically

  • Laser Homes automatically

  • X, Y origin is always the top left corner of your job

  • Screen on laser controls laser head

    • Person icon controls the jog speed. Tap it to change from fast / medium / slow

    • Arrows around person icon control the X / Y jog

    • Arrows to the right control Z height

  • Use the Z-stick to focus the Z height

  • Jog perimeter, either using buttons on screen or in the Retina Engrave Software

  • Estimate time

  • Explain pause and stop

  • Raster, then trace, then cut.

3) File Set-up

All files should be saved in PDF Format.

Choose if vector content and / or raster content will be imported by clicking on arrow next to picture icon. We should always raster first, then trace, then cut.

Imported files will appear under Layers & Objects.

• Clicking on Raster Layer will allow changes to the raster settings

• Clicking on Vector Layer will allow changes to the vector settings

**Important: All visible layers will run when hitting play. Hide or delete any unnecessary layers.

Rastering

• Like a printer, moves back and forth and fills in area

• You can control: speed, power, b/w threshold, DPI

• Black/White threshold is the level that divides black, what gets engraved, and white, what does not 

• It takes approximately 1 minute per square inch

• Choose between Threshold (no dither) and Halftone for different rastering results

• Default settings for Rastering are 30% Power, 100% speed, and 120 Threshold, and shouldn’t need to be changed between various materials

Vector Cutting / Tracing

• Follows the vector lines to either trace a shape or cut through material

• Different line colors can have different settings

• Drag the colours to reorder the cutting order. Laser will cut from the top to the bottom of the list

  • Tracing should be first

  • Cutting should be last

• You can choose from a list of pre-programmed settings based on the material that you’re using, to import the proper settings

• You can also set the Speed, Power, Current, and Passes manually. 

• Never use more than 60% current and less than 20% speed!

Once settings are input, do the following:

• Make sure fan is on

• Maker sure support systems are on

• Run job perimeter (it will run continuously until you tell it to stop)

• Hit play and all visible layers will raster / cut

Commonly Used Settings

*please note, these are just a guideline and you should always run a test on your material

Settings on unfamiliar material

• • Run test cuts, start your guesses settings based on the closest material

Cleaning Your Material

• Burn marks can be sanded off of wood

• Acrylic can be cleaned with soap and water.  DO NOT use rubbing alcohol, as it will cause fractures in the acrylic.

Create Keychains

• • Have each participant create a keychain using “LaserLab 101 - Keychain.svg” as a starting point

  • Demonstrate the technique of jigging, by flipping the key chain and rastering the back side

Cost

see current rates on website here: makerlabs.com/membership

FAQ

• No Connection/Asking for IP address? 

  • IP address 169.254.239.1

  • Still not connecting? Try in this order:

• 1. Unplug the laser, by usb, from the computer, then plug it back in

  2. Shut off the laser, using the red button, and turn it on again (wait 1 min)

  3. Restart RetinaEngrave 3D

  4. Restart the computer and the laser cutter simultaneously

• Not homed? Press the ‘Home’ button

• Error while jogging - Project too large: 

  • A: homing issue

  • B: if it is properly homed, might just have to override it. Proceed with jogging.

• Laser Head stuck; not moving past a certain point/specific direction. 

  • A: Gantry positions might be locked. Try toggling the Lock button. 

  • B: Still doesn’t work, shut down the laser cutter and reboot it. Give it about 3 minutes to be fully up and running.

My image isn't showing up in RetinaEngrave 3D but is visible in Inkscape:

1. In RetinaEngrave 3D, are the boxes "ignore raster" and "ignore vector" unchecked?

2. In RetinaEngrave 3D, what is your B/W Threshold?

3. Is your image rasterized or vectorized? Rasterized images do not have traceable vector information and can only be raster-engraved. You will have to redraw your image as a vector file in order to have tracing/cut capabilities.

4. Check the Inkscape troubleshooting section below for the most common Inkscape issues

Common Inkscape Issues

• Everything is ungrouped?

  • Use CTRL + A (for All) until everything is selected

  • Then repeatedly hit CTRL + U (for ungroup) until each element is its own component

• Layer and object opacity set to 100%

  • Opacity settings can be found in 4 places

    1. Bottom of colour bar

2. Layer bar

3. Fill tab and Stroke tab > Alpha level should be 100% (percentage) or 255 (hex value)

• Coloured stroke but White fill instead of none? (Results in double tracing)

  • Click on box with X

  • Set Fill to no fill in the Fill & Stroke tab

  • How do you know if something has a white fill? You can check in the bottom left corner; it should say ‘Fill: none’. If there is a white swatch then there is a fill.

Fill versus stroke?

Fill is in the inside of the shape whereas stroke is the outline of the shape. Make sure you're on the correct tab or pressing SHIFT appropriately. (SHIFT & click on colour = stroke. Click on colour = fill)

If still having Inkscape issues, try copying your elements into a blank file.