P3D Re: L shaped stuff for twinning

["Robert J. Vaughan" <k0mz@xxxxxxxx>]

> >    I made two twin-camera bars for mounting a pair of Canon F-1 
> SLRs.
> >One has a base of 170mm and the other is 600mm and both are made 
> from
> >1/2"X1 1/4"X 1/8" extruded aluminum stock.
> 
> 
> 
> Is this the L-shaped stuff?  
Yes.  When the extruded stock is viewed from the end, it looks like an
"L" tipped on its side.

> What sorts of tools can you use for 
> cutting, 
> grinding and drilling this stuff?  I want to make a bracket, but I 
> don't 
> know how to cut it to length, round the sharp corners, and drill 
> holes for 
> the screws.  I've done these with wood, but I don't know about 
> aluminum.
> 
> Thanks,
> 
> -pd
>  Peter Davis

   Aluminum can be cut with a hack saw, drilled with standard metal
cutting twist drills, and filed smooth with a standard mill file.  After
deciding on a stereo base, make a full scale drawing of your camera
bottoms locating the tripod socket, front surfaces, and ends.  Plan for
the short part of the L to be at the front so you can change film without
removing the camera from the rig.  After determining how long you want
the bar to be, use a sharp awl to mark the cut lines.  Use a combination
square to make it square and accurate.  Cut the aluminum to length with
an ordinary hack saw.  Use a mill file to round the sharp corners and
remove the saw marks from the ends.  Transfer the centerlines of your
tripod holes to the aluminum using an accurate finely divided steel ruler
and make a pair of good dimples with an awl.  Holding a small electric
drill as perpendicularly as possible, drill the holes in the aluminum. 
If possible, find someone who has a drill press as it is MUCH easier. 
Aluminum is very easy to work.  If you want, kerosene makes a good
cutting lubricant for drilling.  It can also be drilled dry.  If you have
a vise to hold your work, things are much easier to do.
   The camera bodies will probably have protrusions under the lenses
which will probably interfere with the short side of the L.  You will
probably need to cut out some aluminum material to make your cameras fit
well.  That will be the hardest part of the project.  Use a hack saw to
cut the ends of the cutouts.  Then you can make closely spaced cuts near
one end of the cutout and file out enough material to enable you to get
the hacksaw blade in to remove the rest of the material.  File the cutout
smooth so it won't scratch your camera bodies.  Leica cameras don't
interfere with the L front.
   I like using the L shape as the fronts of the camera bodies will index
up against it for great stability.  You don't want your cameras to toe in
or out so the parapet at the front will prevent that.  But, if you don't
want to deal with the L shape, you can use 1/4"X1" material instead.  You
will need to be careful so that the cameras won't toe in or out. 
Robert J. Vaughan