Adam Seychell wrote:
It's currently used for some high resolution printers.
As for crappy light sources, you just focus the light to a converging
beam onto a *small* pin-hole in shim metal, then re-converge the
diverging
beam from the other side. The pinhole cuts out rays that are not
following
the ideal lens 'ray-trace' path. By choosing suitable focal lengths, the
dot on the film will be smaller than the pin-hole size. Other tricks can
be done to make use of laser pointers too.
The mechanics are easy but fiddly. Mount a laser diode to a platform
that
moves along a finely threaded rod, driven with a stepper. An
anti-backlash
nut is made with two nuts with a spring in between. A printer mechanism
could be used.
http://pico-systems.com/photoplot.html
>I've thought of doing it, but my epson is good enough for the moment.
> Hello group,
> Has anyone here thought about building or even built a drum
> photoplotter based on a red LED laser diode ? This would be used for
> making printing masks, et. There has been much discussion among amateurs
> on building a CNC mill/drill machines, however I am under the impression
> that this is definitely NOT an task for the beginner, even if he/she
> has access the right tools. A drum photoplotter appears simpler in
> construction as there is only 1 axis required to position the light
> head. Basically the drum plotter works by rotating a relatively large
> drum with a film sensitive to red light (available from Kodak)
> positioned around the outside of the drum. The drum spins at fairly high
> speed (> 10 rev/sec) and the light source (red LED laser diode and
> focusing lens) slowly and accurately moves along the length of the drum
> in a straight line. The spinning drum sounds relatively simple to build.
> The moving light source looks a lot more complicated / expensive. My
> only thoughts how to go about this is to use a ball bearing screw and
> linear bearing. I priced some ready to go ball screw guided assemblies
> but the costs were prohibitive. Is there no other option ? I own a drill
> press and a small lathe in my workshop. I am open to all comments.
It's currently used for some high resolution printers.
As for crappy light sources, you just focus the light to a converging
beam onto a *small* pin-hole in shim metal, then re-converge the
diverging
beam from the other side. The pinhole cuts out rays that are not
following
the ideal lens 'ray-trace' path. By choosing suitable focal lengths, the
dot on the film will be smaller than the pin-hole size. Other tricks can
be done to make use of laser pointers too.
The mechanics are easy but fiddly. Mount a laser diode to a platform
that
moves along a finely threaded rod, driven with a stepper. An
anti-backlash
nut is made with two nuts with a spring in between. A printer mechanism
could be used.
http://pico-systems.com/photoplot.html