Week 03. Computer-Controlled Cutting

Assignments for this week

Group assignment

• characterize your lasercutter's focus, power, speed, rate, kerf, joint clearance and types

Individual assignment

• cut something on the vinylcutter
• design, lasercut, and document a parametric construction kit
  • account for the lasercutter kerf
  • the kit must be able to be assembled in multiple ways
  • (for extra credit) include elements that aren't flat

What I've done this week

1. Characterize my lasercutter's parameters
   • About my lasercutter
   • How to characterize
   • Results of tests
   • Parameters I recomand
2. Cut a logo sticker on vinylcutter
   • Design a logo
   • Cut with Vinylcutter
3. Make a parametric construction kit with lasercutter
   • Design a construction kit
   • Parameterize the constructoin kit
   • Lasercut the construction kit
   • Play with the constructionkit

1. Characterize my lasercutter's parameters

Trotec Speedy 100

Technical data of Trotec Speedy 100

Working area	608 x 303 mm
Max. height of workspace	170 mm
Laser type	CO2
Laser class	2
Focus length	2inches (approx. 5 cm)
Max. processing speed	2.8 m/s
Max. acceleration	40 m/s²

How to characterize

In Jobcontrol for trotec you set the scanning speed, laser power, pulse rate and scanning iteration.

I made a design to test the scanning speed and laser power for both cutting and engraving.

You can define 16 different laser conditions at a time.the 16 laser conditions are identified by colors on the following table:

No	Color	R	G	B
1	Black	0	0	0
2	Red	255	0	0
3	Blue	0	0	255
4	Desert	51	102	153
5	Cyan	0	255	255
6	Green	0	255	0
7	Grass	0	153	51
8	Forest	0	102	51
9	Olive	153	153	51
10	Brown	153	102	51
11	Walnut	102	51	0
12	Plum	102	0	102
13	Purple	153	0	204
14	Magen	255	0	255
15	Orange	255	102	0
16	Yellow	255	255	0

I designed the test model as the following images.

I made this vector model in a SVG file, and ran the laser cutter row by row changing the the scanning speed every time.

Results of tests

Results from the Engraving test - Acrylic 2 mm:

Results from the Cutting test - Acrylic 2 mm:

From the cutting test, little conditions came out to completely cut. So, I tried scanning twice with the same conditions.

Parameters I recomand

From the results, the following laser parameters:

	Engrave	Cut
Power	100%	100%
Speed	50%	1%
Iteration	1 time	2 times

Check kerf

I used Kerf Check Parts Generator to make a model to check kerfs.

The joints fit best in kerf of 0.05 mm.

2. Cut a logo sticker on vinylcutter

Design a logo

For the vinylcutter assignment I decided to make a logo stick. I planend the logo to be a homage of my final project. I'm planning my final project to be a lamp with lattice shells. So, I designed my logo as a perspective view of a lattice shell.

Prepare a model to vinylcut

Step1. Make a 3D model of lattice shell.

Step 2. Cut the shell with a plane.

Step 3. Project to the plane.

Step 4. Move the projection to the base plane.

Step 5. Fill the part

Step 6. Turn the figure into binary image

First I turn the boundary into binary image. In the next step I turn trace bitmap to turn the raster image into vector image. However, if the boundary was binary, the boundaries become double lines and the vinyl cutter will cut the lines twice.

So, when you make the binary image you must fill the model with either black or white.

Step 7. Make vector image.

Trace bitmap in inkscape and save it as an EPS file.

Now I am ready to vinylcut!

Cut logo with vinylcutter

The vinylcutter I used was Graphtec Craft Robo Pro.

Insert vinyl in to the cutter from the back.

Set the blade

Here are the settings of the cutter:

Set thr cutter to the initial position.

Load SVG EPS file to Graphtec Studio.

View cutting ploter

Send data to the cutter

Cut with vinylcutter

Remove vinyl from the cutter

Cut off area with the logo

Remove the parts you don't need

Transfer the logo to a transfer sheet

Finish!

Stick the logo to my PC.

3. Make a parametric construction kit with lasercutter

Design a parametric construction kit

I designed a parameteric construction kit that could be constructed in 2 ways:

1. press-fit with chamfer
2. insert sticks in holes

The main part of the kit is a right polygon with a groove for press-fit on the center of each edges and a hole on each corner. After, designing an edge I used circular pattern to make it a polygon.

I also designed a support part to insert in holes.

Here are the parameters for the kit.

Lasercut the construction kit

I made a SVG file for laser cutting.

Laser cutted the kit

This is how my kit looks like:

Play with the construction kit

Constructing the kit only with press-fit:

Constructing the kit with press-fit & inserting:

Files

• Model to test laser parameters (.svg)
• Model to test kerf (.svg)
• Model th I used for vinylcutter (.svg)
• Parameteric construction kit (.svg)