A PCB printer for photoresist which uses a PHR-803T Blue-Ray™ pickup

About a year ago my brother and I engaged on a quixotic project to build from scratch a low-cost PCB printer for photoresist. 

Finally we did it using a Blue Ray™ optical pickup (PHR-803T) and his UV laser/electronics to sensitize Dry-film.

The optical pickup is used through his own connector without any modification. We deduced the pinout using reverse engineering and designed a driver for an Arduino UNO to control it. Basically, we can adjust the laser power, turn the laser on/off, move the focus lens servo and read the photodiode array signal.

The control of the pickup allowed us implementing a laser auto-focus algorithm based on the astigmatic method. Is the same method used to focus the laser beam on the Blue Ray™ disc.

The mechanics is a X/Y Cartesian robot which moves the pickup with two Nema 16 stepper motors and T2.5 timing-belts.  Most of the printer framework has been printed with a 3D Reprap printer, so it’s replicable.

We also developed the Arduino UNO firmware, based on 3D printer firmware Marlin, and the server side software which send the HPGL commands to the printer. Eagle Cadsoft complete the “tool-chain”. It supports HPGL in his CAM processor, so is easy to design the circuit with Eagle, generate the HPGL file and send it to the printer.

DiyouPCB is a prototype and it's still not perfect: we have some resonance and vibration issues that affect the quality of printing, but it's a first step to have an alternative method to indirect methods as the famous toner transfer.

We shared all the information about how to build it and use it in our web site www.diyouware.com.

Our next project will be to build an UV resin 3D printer using also the PHR-803T.

Charlie & Victor