There are other Lexmark models that work, but I've been sworn to secrecy by the person who modified one who wants to keep the price down for now.
HP printers are very readily available for very little money, and some of them are easily modified to physically pass copperclad. However, when they print, they usually print outlines of the traces, not the full traces. I have found some materials that you can coat the pcb with that solves the problem, but I really wanted not to have to pre treat the pcb before printing.
I'm pretty sure the problem is the voltages used to charge the drum. In a few months I'll have a lot more time to spend on this, and one thing I want to do is experiment with changing the voltage on HP and other printers.
I think that Brother printers will print to copper, but they are hard to modify the paper path because the paper actually travels through the toner cartridge / drum removable unit.
Mark
At 04:38 PM 1/6/2015, you wrote:
Anyone have any success with printers other than the Lexmark or the Ell 1720?
Mark: Any thoughts on why those printers work but not the HPs?
LeMar