Fifth Element MultiPass Tutorial
A fellow fan, collector, and builder recently purchased a multipass kit from me and had the bravery and knowhow to
fill it to the gills with electronics. Well, ok, maybe that's an exaggeration, but he did manage to complete a task that
I failed at, and for that I am forever grateful. So presented here is his original "show off" of his beautiful build up, followed
by his wonderfully written and illustrated electronics tutorial. Many thanks go out to Mike Rush, who offered to let me post this
information on my website.
A while ago I bought one of Matt
Munson's excellent multipass kits which, due to a lack of spare
time, unfortunately sat around untouched for a while. 
One day recently I looked at it and decided that it deserved
better, and that if I did a little bit every day I'd get it done
eventually. To give myself added incentive I told my wife that I was
making it for her; she also loves Fifth Element.
I didn't take any
photos during the buildup as they wouldn't have been very interesting
(with the possible exception of my look of confusion upon first opening
the kit). 
Once I'd read through Matt's detailed and thorough
instructions a few times, it all fell into place, and gradually I got it
done.
So with apologies for my lack of photographic
skill:
I couldn't really build a prop with an LED in it, and
not make it light up! I had to figure this part out for myself
though, which meant building a switch from scratch as I couldn't find one
small enough.
I used one 3V battery. For future access I secured the
back of the compartment with screws, as suggested in Matt's instructions.
These were the tiniest screws I could find!
I know there are things I could have done better, but
overall I'm very happy with the way it turned out, especially as it's the
first thing I've built for years. 
And thank you Mr Munson!
For those who asked, here's a brief tutorial on how I did
it. Sorry it took me a while. This is not necessarily the best way... just
my way.
Okay, so this is the general layout of the inside of
the kit. The button is provided and so is the LED. There's a nice void for
a battery. Everything else was guesswork! As you can see there's not a lot
of room, especially to and from the LED.
The way the kit is built makes it nice and simple
to drill holes and attach the back plate (a disc) with screws so that I
had an access hatch in case the battery ever needs changing.
I got these screws by dismantling an old keyring
gizmo - it happened to use the smallest screws I've ever seen, which was a
lucky find.
Now, power. In my local supermarket of all places I
found a range of flat, round 3V batteries which fit perfectly into that
void. These batteries might be for cameras, I really didn't bother to ask.
The next task was to get the LED prepared. Here's the LED;
it's actually got two diodes in it. You can light them up individually or
together.
For a nice bright, even light I wanted them both on. By
trial and error I found that I got the best results with them wired in
parallel and connected straight to the battery. I probably should have
used a resistor or something, but I took a chance. The light is only going
to be used for brief periods at a time anyway.
Turn it over and it looks like this (roughly):
Each diode has two terminals. I needed them
connected in parallel. Normally this wouldn't be difficult, but space was
at a premium and I had to do it as flat as possible - almost like working
in 2D.
First I bent down one positive and one negative. These would
eventually be connected to the power.
Then I had to connect the two remaining terminals
to them. My solution was to bend them like this, and then solder at the
points circled:
I knew that this might be vulnerable to damage (and
I also knew that once it was inside the multipass I'd never be able to get
at it again) so once I had soldered on two wires, I covered the base of
the LED in epoxy to seal it. After that I rubbed it over a sheet of wet
& dry paper until the base was flat and I had reduced the height by as
much as I could. The four 'legs' in the corner were much shorter by now.
Checking the film I noticed that the LED does stand quite proud from the
main body.
The next problem was the button. Try as I might I could
not find a button tiny enough. In the end I gave up and decided to
'MacGuyver' something together.
That electronic gizmo I mentioned
earlier had another useful part - a little metal disc with a sprung
protrusion, which sits under the battery and keeps pressure on it. I was
able to use this just as it was. First I stuck some copper tape onto the
inside of the 'hatch', from one side to the center. Then I soldered the
little contact disc onto the middle. Here it is so far:
Along the same lines, I put copper tape onto the
back of the button, and made a nice large blob of solder in the centre.
(Sometimes simple is best.) This would be what actually makes contact with
the battery and completes the circuit.
The last thing required was some kind of spring, to
keep the upper contact off the battery until the button is pushed. Once
again I couldn't find the perfect spring, so I found a keyring of just the
right size, and forced it open slightly; hey presto, a spring! And a
pretty good one, too. The spring was also attached to the back of the
button. Before it was attached I put some insulating tape over the copper
tape. (Otherwise the circuit would have been permanently complete, via the
spring itself.)
So here's the final layout:
I soldered the wires from the LED onto the two
copper tapes (making sure I had the polarity correct of course). Then all
that remained was to insert the battery, screw on the hatch, turn it over,
hold my breath, and press the button! Hey presto - "mool-tee-paas"! 
I hope my diagrams make sense. I know they're not
quite to scale but I wanted to make it as clear as possible. I'm really
pleased with the way my multipass turned out, and if I can help anyone
else to do the same then it's worth it.
Good
luck!
