Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

John,
Glad you are still playing with it, I remember when you did the first posts.  A photo plotter is still on my to do list of projects.   I managed t scrounge up a large photo copier drum that should work well for the photo plotter drum once I make some end pieces.

Are you using a PID servo loop to run your motor at fixed speed?

I am thinking of using a Blue Ray  UV laser diode instead of the red laser to allow use of blue sensitive film and a red room safety light.  Though I have not looked at the availability of sheet film these days.

What sort of lens did you end up using and did you do any spot rounding?

What did you use to drive the pixel video to the laser diode?  I was just thinking of shunting out the lasers current source supply with a FET or transistor across across the laser diode.

Craig