Homebrew PCBs

I saw the thread concerning the mod of the Lexmark E260 and was inspired to have a go.

Not wanting to waste any money, I dug around in the junk cupboard and found an old Laserjet 2200DN. Seemed as good as any as it has an almost straight-through paper path.

A few simple mods and 2 hours later and the unit can print direct to PCB - no electrical mods. In fact, it was simply a case of reducing the pressure on the registration rollers and the transfer roll for the added thickness of the PCB (I only had 1/16" single-sided board floating around).

Because the LJ2200 triggers imaging from the registration sensor, and the registration roller is before the sensor, once the board starts feeding through the registration roll the imaging is identical every time. I couldn't be bothered bypassing the fuser/thermistor but the LJ2200 has a transport assembly between the drum and fuser of about 6" so the PCB simple sits in this gap after imaging - I remove the drum, list out the PCB, and reinstall the drum.

I have printed some test patterns, down to 3mil traces with 3mil spacing. Under a magnifying glass the traces appear uniform and even. I haven't bothered to try fusing the traces or etching at this width only because I don't need to go that small... 10mil is small enough for what I do, and that etches just fine.