Tech Forum
back service reports as an
unreachable private line?
#5048 Ed Research
Indiana, PA
I have just finished building a
small CNC router table. It works well
for making relatively shallow cuts, like
in PCBs. I would like to start working
with plastics, like Lexan and PVC.
These are more difficult to cut with a
small CNC router, since they are
normally 3 to 6 mm thick. I know of
ARC welders that can be used to cut
through sheet metal, but I am looking
for "simple" lasers that can be used to
cut through these plastics and not
metal. Is there a solution out there?
#5049 Ronald Wijngaarde
The Netherlands
adapter cable, but none of them
works. I'm guessing that there is
some other incompatibility
preventing this old keyboard from
working on a more modern
computer.
Can anyone point me toward the
parts and instructions I would need to
build a new keyboard from this old
one's keys and a modern PS/2 bit of
electronics or suggest another way to
get it to talk to a PS/2 keyboard port?
#50410 Dick Steffens
via Internet
battery, but doesn't run in sync
with the sound, which I’ve recorded
on a digital real time recorder.
I’m looking for kits or plans to
build my own crystal sync for a 7.2
volt motor. I tried searching the
Internet, but there is no information
available! Thank you!
Can anyone suggest a source for
negative-acting, photo-sensitized
boards, such as those Kepro used to
supply?
#50411
Don Wruck
via Internet
I have an old keyboard (from a
Wyse 2108 computer, vintage 1988
or so). It has a fantastic touch that I
have been unable to find in modern
keyboards. I've tried all 24 possible
combinations of the four signals in an
ANSWERS
[1048 — January 2004]
I have a Super 8 motion picture
camera that runs on a 7.2 volt
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#1 It may be impractical to add
crystal sync to your Super 8 camera
unless you want to heavily modify the
camera — a job best left for
professionals. You’d need a service
manual first and you’d be attempting
to control the motor speed while
sampling its speed with some sort of
tachometer device. That signal would
be fed to a phase locked loop and
compared to a crystal-based
reference. It’s a very ambitious
project and not at all for the casual
tinkerer. However, there is another
alternative that might work,
depending on what type of film you
are trying to produce and requires no
equipment modification.
If your final film is to be edited
and shown on a Super 8 sound
projector with magnetic stripes on the
film, here is a suggestion. Most
cameras and projectors run at a fairly
stable — but perhaps inaccurate —
speed. Try loading your location
sound into a computer with an audio
editing program.
The program will allow you to
make adjustments to the speed of the
audio without changing pitch. With a
bit of experimentation, you should be
able to get your sound to sync with
your film for at least a minute or so.
You can then dub it — perhaps in
short sections — to your magnetically
striped film as it runs through your
sound projector.
Sure, there are limits to this, but,
if you are committed to shooting and
showing Super 8 film, it may be your
cheapest fix. Try downloading the
open source program Audacity — it’s
free and very cool
( audacity.sourceforge.net) and
available for PCs and Macs. It has all
the features you will need to not only
correct your sync, but to actually
build a soundtrack.
Jim Addie
La Grange Park, IL
96
Circle #46 on the Reader Service Card.
MAY 2004