Revere Flash Adapter (fwd)

[Yiing Lin <ylin@xxxxxxxxxxxxxx>]

---------- Forwarded message ----------
Date: Wed, 17 Jan 1996 14:56:00 -0500
From: James R. Motley <ex836@xxxxxxxxxxxxxxxxxxxxx>
Subject: Revere Flash Adapter

I prepared this response to Patrick's question to send directly to
him but after reading the responses in Digest 1119 pertaining to
filing down the Revere hot shoe Button, decided that others might
also be interested in how I made an adapter without altering the
camera.

Hi Patrick,

I made a flash adapter for my Revere Stereo by shaping
a piece of 1/4 inch thick aluminum bar stock into the 
shape of a flash shoe which would fit into the Revere hot
shoe mount and press fitting a PC flash terminal (socket)
into a hole drilled into the top of the adapter.  The 
flash is then mounted onto a flash bracket and the PC 
cord from the flash is plugged into the PC terminal on the
adapter. I usually use a Vivitar 285 flash mounted on 
a Stroboframe bracket. I believe this one is called a 
flip-flash and I believe the least expensive of the 
Stroboframe brackets---which I think is also the best of 
the Stroboframes. Almost any bracket and any flash with
a PC cord could be used.  Ideally, the bracket would hold
the flash about centered over the camera and high enough
to minimize "red-eye".

In making this adapter I used a hacksaw, regular 1/4 inch
drill and circular and regular flat files.  If you have 
access to a machine shop with good metal working tools,
the project is simpler and much faster.  With my crude 
tools, I had to frequently check fit as taking off too
much metal means starting all over-- and even with better
tools you will still need to check frequently in the 
final stages.  As with any metal working project, EYE
PROTECTION IS IMPORTANT.  YOU NEED TWO GOOD EYES TO SEE
3-D.  Also, as I indicated in the short message I previously
sent,  I did not alter the camera in any way.  While the 
fit is tight enough to leave in place all the time, the 
adapter can be removed at any time.

Also as I mentioned, the key part is the PC terminal (socket).
If you have a lot of junk cameras, you may be able to remove
a terminal which might work.  The one I used was purchased
from a camera repair shop which I believe does the majority
of the repairs for professional photographers in this area.
They indicated that this was a Hasselblad type terminal.  
As I'm sure that Hasselblads are used in your area, I suspect
that you won't have any problem finding this terminal. The
price was a little over $8. (Had earlier been about $5 but
the earthquake in Kobe, Japan destroyed parts and facilities
driving up the price so I was told--I thought it was 
interesting that repair parts for Hasselblads came from Kobe.)

The body of the terminal is threaded, probably with a metric
thread.  The repair shop did not know the thread size and
really didn't care as the body of the camera was threaded 
to accept this terminal.  If you can determine the thread
size and get the proper tap, the terminal could be screwed
into the adapter rather than depending upon a press fit.
For reference, the dimensions as measured with a digital
caliper were as follows:
                               inches      mm
Diameter of the top flange      .275      6.98
Diameter over the threads       .232      5.88
Overall length                  .270      6.88 
There is a screw at the bottom which is intended for the 
electrical connection for the center "hot" post of the PC
terminal.  This screw touching the Revere Hot Shoe Button
makes the "hot" connection and the aluminum adapter makes 
the ground connection. 

I used a hacksaw to cut a piece of 1/4 inch aluminum bar
stock to a rectangular (almost square) shape, cut away the
front to back sides to leave a flange at the bottom of the 
adapter to fit into the Revere hot shoe, cut a front to back
channel in the bottom of the adapter so that the adapter
could be pushed into the Revere hot shoe without contacting 
the hot shoe "hot" button, drilled a hole thru the 1/4 inch
aluminum using a drill a little smaller than the thread
diameter of the PC terminal, and after ascertaining that the
adapter gave a very snug fit, sizing the hole to give a 
press fit and pressing the PC terminal into the hole.  Be
absolutely sure that the adapter fits properly before 
inserting the PC terminal as the terminal can be ruined
trying to get it out of a good tight press fit. Use a wood
block over the terminal when pounding or pressing it in.
Could use wood on top of terminal and wood on bottom of 
the adapter and a vise to press it in.  Could chill the 
terminal with a chilling spray before pressing it in.
Obviously tapping the adapter and screwing the terminal 
into the adapter would be better and safer if you can 
determine the thread size and find that size of tap.

Instead of making the bottom flange perfectly flat, I filed
each side with a taper from the center to the side edge. This
made it easy to keep checking the fit and filing a little
more until I got a snug fit. (Actually, using hacksaw and 
files rules out any possibility of "perfectly" flat, or 
perfectly straight but this doesn't matter as long as you
get a snug fit with no contact with the Revere hot shoe 
Button except that the the bottom screw of the PC terminal
must contact the Button for the electrical contact when 
the adapter is pushed into place.)  How's that for a lonnngg
sentence? :)  If the aluminum used is less than 1/4 inch
thick, you may have to use a thin washer or some type of 
shim to lift the PC terminal to allow proper contact with
the hot shoe Button.

As a guide, the measurements taken with a digital caliper 
for my adapter are as follow:  (What's funny is that I was
taking four place precision measurements of a crude adapter
where nothing was flat, straight, or parallel.) Anyway:

                            inches        mm
Thickness                    .276        7.01
Length-front to back         .663       16.84
Width--side to side          .715       18.15
Center of hole for PC
terminal from back.          .304        7.72
Narrow width at top after
material removed from sides. .432       10.97
Scooped out bottom-Width     .333        8.45
                  -Depth     .096        2.44
Thickness of flange-tapered  .085-.078   2.17-1.95
Note: aim high and file off little at a time until snug.
Also note:  Be careful in removing material from the bottom 
for clearance of the Revere Button so that the side walls
do not get so thin that there is no strength.
Another note: Note that PC terminal is not exactly centered
front to back as it just shoved against the Button.  Actually
the adapter could be reversed but then it would protrude past
the back of the Revere hot shoe.  Use a center punch to mark
the spot for drilling the hole so that the drill does not
wander.

My crude adapter may not be pretty, BUT IT WORKS!!!

I also have a like adapter with slightly different dimensions
for my Realist.  And, I have used the same Hasselblad type
of PC terminal for making an adapter for my VM Personal. This 
one electrically is more complex requiring the use of a spring
and plastic insulator because of the different(strange) flash
connection, but here again, it works and is pretty (hardly
noticable on the camera as I used gun blue to darken the 
aluminum).  Like "they" say, there's lots of ways to skin a cat.

BTW, the Hasselblad PC terminal is probably about as close
as I will ever get to owning a Hasselblad. 


Best Regards....Jim Motley    ex836@xxxxxxxxxxxxxxxxxxxxx   


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End of PHOTO-3D Digest 1120
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