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Laser Exposer

The laser Exposer is a project started in April 2014 to enable direct exposure of photoresist-clad PCBs to simplify the production of custom PCBs


  • Direct exposure of Kinsten type photoresist boards
  • “Print” from host PC
  • Open source development
  • Safe to use within the space


  • Safety of near-UV lasers
  • Integration of laser, motor and spooling components
  • Keeping within the project space and cost constraints

Proof of Concept



Donor Chassis: HP scanjet 5470c

  • 10PU-M204-G2ST hybrid stepper motor for y-axis, 3.75 deg/step
  • LCD screen and 11 buttons
Donor Scan head 1: (Retired?)
  • (Wrong, see below) Laserjet 6L, model number C3990A serial JPWX004992 (if an aluminium plate in the scrap box is to be believed)
  • Manual: HP
  • Unable to hack the motor controller board easily enough. Will consider looking at it again another time
  • Brushless motor with integrated hall sensor
  • Hexagonal mirror
  • Update 26/4/14: Not a 6L. Maybe samsung SCX-4725? Per image recognition off Alibaba
Donor scan head 2:
  • *Offered for use by Luke


  • Salvaged Blu-ray burner laser from a PHR-803T sled

Electronics: Arduino Mega 2560-compatible board (Hobbyking) Stepstick pololu breakout board



Ideal: Accepts postscript or acts literally like a monochrome printer - unlikely given difficult in spoofing USB ID, making compliant with printer signals and cross-platform compatibility Option 1: Upload an image (bitmap) to the device, and it “prints” it out Option 2: Control using pronterface or similar (possibly control using Marlin, similar to CnC mill)


Option 1: Marlin for vector-based drawing Option 2: Custom for image-based “scanning”


15/04/2014: Donated Scanner, arduino mega and deconstructed some of the above

To add:

  • Images (Need to be renamed)
  • Disassembly of scanner chassis

Mirror motor controller

The mirror motor controler has five input pins. Pin 5 has “5” on the silkscreen next to it It has a large IC, made by panasonic (in 1995 so different name) and undocumented. Labelled “AN44002A / 95OC1743” presumably from Oct 17 '95 Folowing sites / posts about various control boards

Links (of varying use)


Pinout: 1: unknown 2: unknown 3: unknown 4: ground 5: Vcc

Attempted reverse engineering: 5v an 12v to Vcc and GND - no blue smoke - pins 1, 2, 3 all ground / AC noise Pins 1,2,3 pulled to ground via 10kΩ: Pin 1: 3.13V. No signal from motor spinning. Pin 2, 3: Ground Pin 1 pulled to ground, pin 2,3 pulled to 3.3V - pin 1 unchanged (logic high) pin 2,3 at 3V. No signal from moto spinning. Pins 1,2,3 pulled to 3.3V via 10kΩ: all 3.3V / AC noise. No signal on spining motor

Pin 1 pulled via 10k to ground, measures high; undriven pin pulled to ground 3.3V square/sine/triangle wave to pin 2,3 with no result

Pin 1 pulled direct to ground, measures low; undriven pin pulled to ground 3.3V square/sine/triangle wave to pin 2,3 with no result

project/member/dormant/laser_exposer.txt · Last modified: 2015/04/16 20:22 by projectgus