P3D Project Four: Modernized flash for Stere-All

[Tom Deering <tmd@xxxxxxxxxxx>]

I know these projects are far too rudimentary for many of you.  But the
other beginners might be encouraged by the fact that I have no experience
with camera repair or stereo photography.  Others can do this if I can.

Project Four: I converted my Stere-All for use with a modern flash.  This
turned out to be a lot more complicated thatn I first thought.  The simple
part is to notch out the bottom of the flash to fit with the protruding
knob on the hot shoe.  The way I did it, I could still use the modified
flash in a regular camera, so nothing lost here.

I used a dremel moto-tool to carfully carve out a tiny groove, although I
just as easily could have lopped off the protruding knob on the camera.  I
didn't want to cut up my nice fifty-year old camera, (although that idea
goes out the window in the next step.)

With the flash working, I tested by taking the back of the camera off, and
looking through as I fired the shutter.  I did not see the rectangle of
light I expected.  Then I remembered that a camera this old would have been
synched for a flash bulb, which takes a split second to come up to speed.
So the camera fires the flash long before the shutters are open.  But my
electronic flash is much faster, so with this timing the strobe has long
since extinguished by the time the shutters open.  I confirmed this by
pointing the flash at the mechanism inside as I fired it.  The strobe
effect froze the movement of the mechanism, and I could see it was firing
far too early.

The Stere-All has a revolving wheel inside which opens the shutters and
fires the flash.  I examined the machanism, and determined that I could get
the flash to fire later if the revolving wheel had a bump in a different
place.  Knowing that a mistake would ruin my new camera, I carefully
measured where the new bump should go, and then measured again.  The wheel
is made of thin aluminum, so I just trimmed it with scissors.  I used the
Dremel to smooth the edges.  This part worked out perfectly.  The same
open-back test above later showed the synch to be perfect.

I was totally sucessful except, I broke two things in the process.  First,
I stretched a spring in shutter machanism.  I had to manufacture a tiny
washer to make it work again.  And I broke something else:  When I first
opened the camera, I noticed an oddly bent piece of spring steel.  I
thought, "Ah ha! That's why the flash doesn't work!", so I straightened it
out.  Turned out to be part of the frame counter, not the flash synch.
Took a couple days trying different shapes to make it ratchet properly
again.  I'll have to be more careful, _next time._

Tom



------------------------------