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Viewmaster wrote:The forum seems a bit dead at present and probably there is little interest in this laser
project anyway.
Viewmaster wrote:Although the rack and pinion for frame is working OK it's now in the melting pot !!!
I think I have a better idea using one tiny mirror as at present for line scan
but a second tall slim rotating mirror for frame. The laser reflection from the first
mirror 'running up and down' the second mirror !
The tiny one does the line scan and the vert one frame.
Although the scan width might be limited to just under 180 degrees
the frame speed of the system could run very fast if required,
unlike the present rack and pinion.
Unlike my rack and pinion there is no fly back return required. Nor is there
any non linearity either. Another bonus is the rig would be very small in size.
Just two tiny (no need for power to drive a rack) PWM motors and tiny mirrors
and one laser. No micro switches etc either.
Software much the same as before.
We shall see............. I do luv melting pots !
Viewmaster wrote:Harry, you seem to have done it all before, on your own, years ago!!
Why do I bother except I will not have any varying motor speed rotational sync
problem to overcome and its near 180 degrees............
As the the old cockney song of old said, "My old man said follow the van........."
In my case it's, " My old laptop will follow the scan."
Have you ever made a matching laser camera and recorded
its output for future playback ?
I do hope now that my bloody melting pot gives it a rest as it gets
expensive to keep it melted
Viewmaster wrote:Harry, I am not interested at present in getting moving pictures.
Just to experiment in software processing various lines/frames speeds, scan widths
and heights on the laptop.
So keeping it simple with single mirrors for line and frame. They will be quite OK for what
I wish to do and keeps construction time down.
In any case, even at a lowest 1 frame per second there will be nil flicker on this system as
the next incoming image can just easily overwrite the previous one on screen. So a
constant picture is presented.
It was the Cambridge rig that demonstrated to us that by using a PC one could generate
large pictures from a simple scanning system.
[/quote]I have 'bit' the' byte' bug now.
Viewmaster wrote:Harry,as you are into so many NBTV things I daresay you may have
meddled with this non opto pulse generation.
For the frame mirror (and maybe line) instead of using opto to get pulses
I am going to use a tiny home made commutator. It might be intermittent but I like to
try new things I haven't yet done. Frame revs are very low .
Maybe you have experimented with this system in the past?
In parallel with the frame shaft I have tapped a 6 BA hole into a nylon section and put in a brass screw.
Then turned down the nylon diameter until the screw is partly exposed.
TWO, very small silver looking brushes, (with 3 forks on each), taken from
a tiny high speed brushed mini motor and mounted side by side, will contact
this exposed brass each rev and so be shorted to each other, thereby giving a pulse.
As there are 3 mini forks to each brush there's a good chance that at least one will do the shorting out
at each rev. To do this on the very high speed line shaft might be a trifle risky though.
Viewmaster wrote:Here's the experimental scanner. Shows worm drive to frame mirror and 45 degree 1/4 inch high speed line mirror
(it's the one held by a jubilee clip!)
Laser shines straight onto tiny rotating line mirror which in turn shines onto slower speed long frame mirror thereby
getting nearly 180 degree max width scan. ( width can be controlled on laptop)
Sorry, there is no Lego anymore.
Harry Dalek wrote: small and having mucked about with this stuff pretty hard get to work accurately and smaller
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