Laser cutter

Laser cutter


I configured laser with lightburn. 30 day evaluation version is available for free.

Software with license is installed on the OTG laptop. Extra licenses are available to OTG members at discount price (20$).

Connect to TP-Link-991D16 network.

  • Controller: Ruida
  • IP address
  • Cutting table dimensions: 1300x900mm
  • Origin in upper (rear) right corner

Z (focus) control should be configured to “Relative Z moves only”, and “Optimize Z moves” should be turned on.

Starting a job


CO2 laser works with invisible infrared radiation. Light you see is from base material burning, not laser light. It’s almost 100W of optical power, so imagine starring at 100W LED lamp. Light looses energy quickly with distance, so starring from few meters is better than putting your head next to the laser cover.

  • Don’t stare at laser while cutting or engraving, especially when working with shiny materials
  • We don’t know yet how much infrared can escape through laser cover
  • There are NO safety switches on access panels, so make sure they are all closed (especially laser tube panel) when operating. Laser will NOT turn off when cover is opened while operating. Also smoke extraction does not work when cover is open. Always close cover before starting.
  • Use red safety glasses (i.e. when working on open laser path, adjusting mirrors)
  • Don’t clean or adjust optics without permission
  • Don’t put anything on control panel (laptop, book, tools, etc…). Button press can activate laser, or crash laser head
  • Don’t try to move laser head beyond laser range, end stops are only on one side

Turn on checklist

  1. Make sure there is nothing inside laser chamber. After power on laser is automatically homing, and may hit something.
  2. Turn on power.
  3. Inspect optics for particles. Mirrors can be slightly foggy, but there should be no large particles stick to the surface.
  4. Make sure chiller is running, and water level is in green area. Lift laser tube cover, and wait for all air bubbles to escape.
  5. Make sure air compressor is running. Check if air is blowing through the nozzle.
  6. Move exhaust fan out of the gate. Turn on exhaust fan. Make sure that pipe at the back is connected properly. Smoke should run parallel to table when there is good air flow.
  7. Remember to turn off fan after cutting/engraving is done (we got complaints from neighbors about noise).

Job setup

  1. Set Z-height for object you’re cutting or engraving. Focus point is approximately 11mm from nozzle. Focus point should be set slightly below surface – 8mm from nozzle is good starting point. To lift or drop table: press Z/U button, then left/right arrow move table up and down.
  2. Move laser head with arrow keys on control panel, or position from software
  3. Use “Laser->Frame” to run laser head around perimeter of your design
  4. When using new material make some test cuts first

Turn off checklist

  1. Remove everything from laser
  2. Pull exhaust fan in
  3. Disconnect main plug


If laser makes unexpected noises, then press emergency stop immediately.

Flames while cutting, material ignites: compressor is not running.

Smoke fills laser chamber: smoke extraction is off, or pipe is not connected properly.

Common materials

  • 3mm MDF – cuts easily, can be engraved. Disadvantages – emits large amounts of smoke, doesn’t look very good.
  • 5mm MDF – difficult to cut, requires 2 passes. Cut leaves heavily charred edges that need to be cleaned, emits a lot of smoke.
  • Cardboard, EPS foam – cuts very easily, emits little smoke.
  • Acrylic (plexiglass) – nice, almost optically clear cut surface. Can be engraved.
  • Painted metal – can be engraved. Caution: reflects a lot of light – don’t stare into engraving area.
  • Ceramic tiles, glass – can be engraved. Top surface melts slightly leaving rough glossy surface. Top paint layer is vaporized. Caution: reflects a lot of light – don’t stare into engraving area.

Cutting thicker wood requires multiple passes, and emits a lot of smoke.

Material library can be downloaded from OTG github.


Online file generators

Guide to materials, including materials that should never be tried on laser cutter

QR code generator – a lot of free vector graphics for laser cutters


X/Y calibration seems to be off. Objects turn out larger than design.

Material library: Lightburn allows for importing and exporting material libraries. There is a lot of experimentation with new materials for both engraving and cutting.

Print maintenance schedule. Maintenance includes cleaning optics, linear guides. We need simple table printed on the machine where we could log maintenance actions.

Special tool is needed for unscrewing lenses and mirrors. We need to machine one from metal.

Cleaning materials: IPA, acetone, cotton swabs, wipes for optics, rubber gloves. Cleaning instructions on the laser.

Exhaust fan is quite heavy. For start we can put it on casters. Eventually exhaust fan should be installed permanently, and turn on automatically before laser job starts.

Measure how much infrared escapes through laser cover. Wavelength is around 10um.

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