Kinematic system

Recently (early March 2024), I built the kinematic system to move the laser head and the print bed.

The laser moves in X (left-right) axis, and the bed moves in Y (forward-backward) and Z (up-down) axis.
All the axes are driven by cheap 28BYJ-48 stepper motors.

Operation as a laser marker

To test the kinematic system and laser control, I used the machine as a laser marker to draw burned image on a paper.
The image (★) was marked on a paper by raster-scanning laser.

The burned image was clear, but there were "zig-zag" artifacts on edges.
As it indicates there are unexpected deviation of X position between left-to-right and right-to-left scan lines, there is room for improvement in mechanical accuracy and/or motion control program.

In the beginning of this year (Jan. 26), before building anything, I did a small experiment to confirm the most important idea of this project: hardening polymer clay with laser.

Methods

The materials are:

• Polymer clay: Fimo Soft (black)
• Laser: VoidMicro LD3070LA
  • Diode laser module sold on AliExpress at approx. $32
  • 5.5W, 450 nm (blue visible light)

The small amount of clay was kneaded and stretched into thin layer of about 1 mm.
Then the small area on clay was irradiated with laser, in a manner similar to filling an area with pen.
The laser power (PWM input) was set to 100%.

Results

The irradiated area became hard rubber-like state, and it was not easily teared apart when pulled.

Therefore, it is proven that polymer clay can be baked with laser.

However, the process generated terrible odor. Safety of this process has to be investigated further.