Homebrew PCBs

Adam Seychell wrote:

> 
> Ok, maybe not such a good idea. Are laser scanners assemblies
> expensive ?
> Still, cannot find a supplier of these "laser mirror scanner motors".
> This looks like the way to go.

It's free (as free beer), or at least i can send you one for free. Is
just like those, a little bigger with a 2 levels 6 faces mirror, more
precise with 3 hall effect sensors and LB1876 driver. Or you could
remove it from a copier machine.

A year ago i had the idea to exchange the IR led in a laser printer by a
UV led. Since laser printers have all the optics assemble in a removable
'box' inside wasn't that problematic doing it. So i asked someone who
works with laser printers, about the optics efficiency on UV and he give
me all the mirrors lenses sensors etc from a fast color copier with
manuals and schematics and said to try it myself! The thing has also
very small stepper motors for mirrors adjustment between colors.

But using it need assembling all this correctly aligned. If i got the
parts in the assembly will be much easier, and the led's  i known about
wont work.

The person is an ebay seller from who i got nice stepper motor and
microstepping controllers and he offered lots more stuff which i ended
using nothing...

BUT there is a much simpler way ( i think ). 
With rotation you will need one 'zeroing' light sensor like on laser
printers ( yes i can offer you one too) and precise timing electronics
say a fast fpga with memory.
My view is to use the laser in a pendulum, moved by a eccentric
connection to a wheel with a motor (like vapor train but opposite). The
motor could me a stepper motor running at 500rpm and you print on both
movements. For 'zeroing' you could use one light sensor on the wheel.
The good thing is if you print only a small line (say 2cm or less) not
only the led power could be constant but if under the 256 count off
'dots' you could do all inside a common microcontroller with low
bandwidth to a computer. It drives a microstepper controller at constant
speed and with a counter turns on and off the laser. The 'commands' need
to be 'print from xx to yy' turning on the laser from position xx and
off on yy, making a trace not a dot. For efficiency the command should
allow multiple traces on same line. The computer needs to calculate the
precise position since each step on the motor is a angle with non linear
relation on the pcb.

Ok writing were is easy, you already get the picture, i will stop now.