Week 3 - Computer Controlled Cutting

Assignment

Computer-Controlled Cutting

Group assignment:
- Do your lab's safety training
- Characterize your lasercutter's focus, power, speed, rate, kerf, joint clearance and types.
- Document your work to the group work page and reflect on your individual page what you learned.
Individual assignments:
- Design, lasercut, and document a parametric construction kit, accounting for the lasercutter kerf.
- Cut something on the vinyl cutter.

From Assignment Details

Assignment

Group Assignments Page, CreativeSpark Node, Ireland

Laser Cutter Characterisation

Fab Lab Limerick has a Trotec Speedy400.

Focus: 2" Lens
Power: 80W, ...however this is an older machine and recent maintenance measured a power drop of >10W between source and cutting position.
Speed: Original Specs for the machine state Max. processing speed: 4.32 m/s, but as this is an older model, I remember 3.55 m/s when we got it first. The software presents each material speed as a % of this value.
Rate: The software uses 1-60 kHz, depending on the settings for that particular material. Timber and Card are at the lower end, and plastics like Acrylic seem to be at the higher end.
Kerf: 0.4mm (see below)
Joint Clearance: 0.2mm (see below)
Type: CO₂ CeramiCore® laser source produced by Iradion GmbH

Kerf Test

Material: MDF 3mm

100% power; 20% speed; 1 pass; 1000 Hz; 10 Power Correction; 0mm Z-Offset; Air-Assist On; Source CO₂;

Measured: 24.6mm (meant to be 25.0mm) So Kerf = 0.4mm, and Joint clearance = 0.2mm

Lasercut a Parametric Construction Kit

The first step was to get familiar with the Epilog. In this case I used the Epilog Flux, and a 3mm Plywood offcut.

Laser_1

The drawing was in Inkscape. The Epilog software understands fills and hairline vectors. You can, additionally, add more to the list on the right. Have them filtered by colour, or type to set up different operations, with different speed and power settings. The open folder icon allows you select a material from the existing library. (Note as you do this may overwrite tweaks you made up to this point, and job-level settings, like resolution).

Laser_2 Laser_3

I experimented with a Grasshopper Script to slice a 3D object with an interlocking pattern. It uses the Contour node and the Region Slits node to do this efficiently. And I will apply OpenNest to lay out a cut sheet.

Grasshopper_1 Grasshopper_1a Grasshopper_3 Transfer to Inkscape Lasercut, during cut Lasercut Finished Cut

Conclusion

I wanted to experiment with grasshopper for this assignment. The limits I found were:

Could not adjust the slot depth (always 50/50)
Could not add notches at opening, or taper, or added clip features.
RegionSlits component produced some self-intersecting boundaries.
RegionSlits missed some intersections entirely.
The assembled model was not assemble-able, numbers not in order and direction of slots not consistent.

Laser_4

Cut something on the Vinyl Cutter

To make use of the Vinyl Cutter, I drew something in Inkscape. The Vinyl Cutter is a Roland GS2-24, and I used a laptop in the lab with the Roland DGA Print Driver.

Vinyl_1

From the roll, cut roughly to length. This is a 300mm roll of polymeric adhesive vinyl.

Vinyl_2

Release the lever at the back left of the machine. Feed the vinyl through the machine from the front. Adjust the wheels. The white stickers correspond to the knurled parts of the bar underneath, so make sure both wheels are within the white demarkated sections. Make sure the edge is parallel with the lines marked on the machine, so that it doesn't misalign itself too much as it moves.

Vinyl_Now_Loading

From the menu, select "Piece" to add.

Vinyl_Putting_In_Page_Sizes Vinyl_Width_And_Height

The carraige travels the width of the machine, and rolls the piece through. It returns the width and height on the display. Update this in Inkscape (Document Preferences).

Vinyl_Arranging_Your_Page