Laser Operating Procedure

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Operating Procedure

  1. Check a CO2 fire extinguisher is available and not empty
  2. Unlock the laser cutter lid
  3. Check table is at correct height and empty of materials/offcuts so no parts interfere with laser nozzle. If the bed looks like it has a residue build up on it, give it a clean.
  4. Turn on (all on one Laser labelled switch):
    1. Laser cooler (allow to cool for 5 mins before proceeding)
    2. Nozzle-clear pump
    3. Extraction pump
    4. Laser (including turning the keyed switch)
    5. Laser PC
  5. Put the material to cut on the laser bed
  6. Adjust the bed height to focus the laser
  7. Position the laser head to desired origin position
  8. Set laser origin to current position by pushing origin button
  9. Open the RDWorks software on the PC and import your design
  10. Process the design and apply correct speed/power settings. Refer to the Laserable materials reference for guide lines on what materials can be cut and the appropriate settings.
  11. If cutting with a new material, test the power and speed settings by cutting a small test pattern on a scrap of material first
  12. 'Download' the design to the laser cutter
  13. Open file Menu by pressing File button, and select your design from the list
  14. Always use the 'Frame' button to show the outline of the cut path before cutting
  15. To cut: Close the cutter lid and press start button (green play triangle)
  16. When you've finished cutting, remove all materials and clean the surfaces inside the laser cutter

Tips & Tricks

Laser Cutter Tips

  • If the laser cutter's user interface does not seem to respond/do what you want, hit "ESC" to return to 'normal mode'.
  • If the jog buttons (arrow keys moving the laser head around) are only moving the head in small single steps rather than moving it continuously, make sure that the jog step size is set to 0.0mm in the Jog Settings section of the menu.

Material cutting Tips

  • The opaque white acrylic needs slightly stronger settings for surface cuts as they are not as visible as in the transparent acrylic (i.e., for similar effect you need a deeper cut). Otherwise seems to cut equivalently to transparent acrylics.

Cut Thickness and Fitting Tips

  • If you want a tight fit of pieces or very accurate sizing, keep in mind that the laser beam has a width of just over 0.1 mm (maybe 0.11 or 0.12 mm). So all exterior cut lines should be offset by 0.05 mm; you can do this very easily in the LaserCutter Software with the "Offset" tool (units are in mm, so enter '0.05' and select 'Outer').
  • The laser kerf is 0.1-0.3mm and varies between materials and cut speeds.
  • For friction fits and tight tolerance parts, the kerf offset can be accounted for in CAD or using the offset function in LaserCut 5.3. One design choice can be to add small bumps that are bigger than the expected kerf, so there's only small bits of contact. This can make it easier to get a friction fit with poor tolerance parts.

DXF Tips

  • DXF Format use R14. RDWorks works best with DXF version AutoCAD R14
  • The DXF file format stores values only (not values and units). The internal units in the laser cutter are in mm. If you set your document's units to mm in the exporting CAD system it should work fine, but generally it is a good idea to have a piece of geometry of known length, e.g. a line 100mm long, or a box of known size around your design. This makes adjusting the scaling a lot easier.
  • If you want to export a DXF from Inkscape see Inkscape Tips below
  • It can be a good idea to check the exported DXF with a DXF viewer to check for strange export behaviour and as a troubleshooting tool. DWG Trueview and CAMBAM (DXF function still works after trial period) are recommended by some hackspace members.

General CAD Design Tips

  • Whenever exporting a vector from CAD software, include a circle or rectangle that's there purely to maintain scale. Something like 100x100. Then it's super easy to check if something funky is going on, and fix it, however primitive the laser cut software is.

Inkscape Tips

  • There's a page to help with Inkscape using Inkscape for laser cutter designs
  • If you want to export a DXF from Inkscape (which is a great, free vector drawing package), then make sure you do "Object to path" from the Path menu for the whole object and then during the export stage, enable "use ROBO-Master type of spline output". This should make sure all the curves and so on work.

Fixing strange issues

Etching doesn't work

When Laser Etching doesn't work
Lines are not closed. RDWorks doesn't warn you about this, but the preview on the laser controller will show the shapes as having no fill. Ctrl-a to select all, then Handle->Curve auto close (may need 1mm Close Error setting to work).
Two copies on top of each other. Copies on top of each other "cancel out" any etching. Delete one copy. You may need to edit points to see the double line, if both the top and bottom shape are joined into one path.
Test with Edit->Preview

When RDWorks will not download to the laser cutter

Try sending a second time
try again with a new name for your design
Check laser cutter is turned on
Restart RDWorks on the PC.

Laser cuts things out more than once

When the Laser cuts things out 2 or more times
Check you don't have two copies loaded on top of each other

Laser will only cut at the top right of the bed

When the Laser will only cut at the top right of the bed
Download again with Position:"current position" selected
set the origin on the laser cutter before Frame or Start

You Hit Emergency stop

When you hit the Emergency stop
The Emergency Stop button needs twisting to re-activate / reset it.
If that fails - check the circuit breaker inside. From the back of the machine, you want to open the lower flap on the left side, which should be unlocked. Near to the back, there is a breaker board. Flip the flippy bit.

Operating cost

The laser consumes ~1000w so << £1/hr energy cost. The laser tube cost also works out at < £1/hr, so the main running cost is for the materials.

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