The goal of this project is to develop a laser head for 3D printing or PCB manufacturing which uses a rotating prism and is easy to assemble.
Cyanotype paper is currently used as it can be developed with water. The current electronics provide the possibility to cut a PCB with a spindle.
Specifications
Specifications were determined from the proof of concept model by exposure onto a camera without lens and OpenCV. More technical details are available in the whitepaper or the business case pitch.
- wavelength: 405 nm
- rotation frequency: up to 21000 RPM, current 2400 RPM
- line speed: up to 34 meters per second @ 21000 RPM
- spot size FWHM: circular, 25 micrometers diameter
- cross scanner error: 40 micrometers (error orthogonal to scan line)
- stabilization accuracy scanning direction: 2.2 micrometers (disabling/enabling scan head)
- jitter: 35 microns (error parallel to scan line)
- duty cycle: 47%
- laser driver frequency: 2.6 MHz
- maximum scan line length: 24 mm
- typical scan line length: 8 mm
- optical power: 500 mW
- facets: prism has 4 facets
- prism dimensions: 30x30x2 mm
Electronics
- Beaglebone green or Ice40HX4K with Icestorm toolchain
- Firestarter cape (laser driver, 3x TMC2130 stepper drivers, PWM spindle and fan control)
Status
An image can be uploaded to the scanner and exposed on a substrate.
An exposure result on cyanotype paper is shown below.
Resolution looks to be around 100 microns. Stitching still needs to be fixed, results in white lanes.
The idea is that through holes are made with a spindle. There is a project on Hackaday where a PCB is cut with an EDM.

An exposure goes as follows (for the result see above).
Acknowledgement
Special thanks go to Henner Zeller for his work on LDGraphy. The electronics and software in this project helped me a lot with constructing the laser scanner, see video.
Software
Hexastorm fork of LDGraphy
Optical design
old FPGA code
Electronics
PCB design
Hardware designs
CAD files
Cartesian frame was donated by FELIXprinters.
Literature Research
White paper @ Reprap
Other Links
Official website
Would this work? https://www.edmundoptics.eu/p/20mm-square-uncoated-b270-window/18799/