This article was first published in 2009.
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One of our most popular recent stories is A Heap of Parts for Nothing! that describes all the
good bits you can get out of any old discarded cordless drill. But drills aren’t
alone – there’s also another very frequently discarded consumer item that has
plenty of good parts inside. The item? A Video Cassette Recorder – VCR.
Now is a great time to be salvaging VCRs. With the
move to DVD players – and even more significantly – digital video recorders,
VCRs are being discarded in huge numbers. You can find them at the tip, at
garage sales - even in kerbside rubbish pick-ups. Maximum price you should pay
is a few dollars – but the minimum (zero dollars) is more often the asking
price.
So why would you bother salvaging a VCR? And
wouldn’t it take hours to pull it apart to get the good bits? Well the answers
are, respectively: lots of reasons, and no.
And contrary to what you might expect, the best
bits are mechanical rather than electronic. Let’s take a look.
Pictured at right is a typical starting point. This is what you
might call a medium age VCR. Older ones are better, and heavy older ones
are better again!
Huh?
Well you see, the heavier a VCR, the better the
quality of salvageable components inside. In fact, to go to extremes, the
ancient U-matic video tape machines weigh an incredible amount (some can barely
be lifted) and inside you’ll find engineering that is fantastic. Solenoids,
switches – but we’re getting ahead of ourselves.
On the other hand, a super lightweight VCR has
generally less of everything you might want. However, any VCR is worth
picking up for its parts.
It takes very little time to remove the cover
(keep those screws!) and strip out the main circuit boards. In fact, it’s worth
stressing that disassembling a VCR is really a quick and easy process – expect
to take perhaps only half an hour to do the first one from start to finish. When
you get speedy, you can do it in 10 minutes.
It makes sense to do all the mechanical work in
one go, coming back to the electronic parts later in the process. So with the
electronic boards put to one side, the next step is to remove the tape transport
mechanism and drum. This assembly is almost always found on a sub-chassis which
is screwed to the plastic of the inner enclosure.
Here’s the inner chassis on its own. Already the contents of the VCR have been narrowed down to just this and
the electronic printed circuit boards.
Throw the rest away as you take it off – the top
and bottom covers, front cover, inner plastic chassis. Anyway, the next steps
involve pulling this piece of gear apart.
You’ll need a good quality medium point
Philips head screwdriver – invariably, some of the screws are tight and once you
start mangling screw heads, it rapidly gets all too hard. You may also need a
very small Allen key and a Torx bit screwdriver.
Here’s one of the absolute pearls. I’m happy
collecting a whole VCR just to pull this part out – that’s how good I think it
is.
But what is it?
It’s the spinning drum that carries the video
heads that read and write to the tape. The drum is designed to rotate with great
precision many millions of times during the life of the VCR and as a result,
it’s beautifully made.
We’ll come back the video drum again in a
minute.
Here’s what we have so far. (1) the video drum (more on this in a moment);
(2) ten springs (nine extension and one compression); (4) 38 machine screws; and
(5) 44 self-tapping screws.
‘He’s joking,’ you’re saying. ‘Why bother
collecting the screws?’ Well, you tell me which local hardware store has small,
plated, Philips head self-tappers in stock? Or a fine metric thread Philips head
machine screw – just what you need as a replacement in a piece of gear you’re
working on? Springs? How many times have you said to yourself: “Hell, all this
needs to fix it is a little spring,” – and then you’ve looked in frustration for
a spring, any spring?
(3) DC brush-type permanent magnet motor that uses
a worm reduction drive to turn a slowly-rotating output shaft. It would make a
perfect winch for a model boat, or a merry-go-round for a model railway layout,
or a bespoke kids toy, or...
Remember all the electronic boards we put to one
side? Well, here they are.
Now I know what you’re thinking – he’s going to
tell us to get out the soldering iron and sucker and laboriously unsolder every
one of these trivial cost components – and who’d bother wasting their day doing
that?
Fair comment – and it’s not me who’ll be spending
the time.
Instead, what I do is identify the bits that I am
very likely to have a use for and that cost more than cents to buy – or that are
not readily available off the shelf.
Components like the colour-coded RCA sockets
(great for anywhere you need a socket on portable gear)...
... and the high power wire-wound resistors
(perfect for dropping fan speed or dimming lights)...
And forget using the soldering iron. All you do is
hold the PCB in a vice, grasp the component you want with a pair of pliers, and
aim a normal heat gun at the solder side of the PCB. It takes literally a minute
to salvage 10 or 15 components – and that’s time worth spending. Here I wanted
the highlighted miniature pushbuttons.
Just check its size of the pushbutton! It’s idea
where you want to add a really unobtrusive momentary switch – whether that’s to
de-activate an alarm or trigger a function.
Video
Drum Disassembly
So
what about that video drum again? Here’s what a video drum assembly typically
looks like. The first step is to undo all the visible screws....
..and
that might involve using a Torx bit or small Allen key.
The
parts like the one arrowed here can be broken off with a screwdriver. Note that you
should always wear goggles as this material easily shatters and is very
sharp.
As
you disassemble the video drum, you’ll start revealing the good bits – like
these precision sealed ball bearings in the alloy housing and the hardened steel
shaft that fits through the bearings.
The
brass collar is held in place on the shaft with an internal Allen headed grub
screw. You’ll need the right-sized small Allen key – don’t try to drill out the
grub screw as the (working!) collar is very valuable.
Some
elements on the shaft are a push-fit. However, the shaft is easily moved if the
element is supported on top of vice jaws and a pin-punch and hammer are used to
push the shaft through. The process is also easily reversible.
It
might not look all that exciting but consider this. You now have a
precision-ground, hardened steel axle. You have two precision sealed ball
bearings that match the axle perfectly. You have two light alloy housings, one
of which is normally a press fit on the axle and the other that houses the two
bearings.
In
almost any application where you need small bearings and an axle (robotics, a
wind vane, small wind generator, model car) these parts can be put to use.
Furthermore, they’re pretty well standardised across all VHS VCRs, so if you
need two axles (or four bearings, etc), just keep on collecting junked machines!
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And we’re not finished yet!
I also collect the
power cords – these are invariably twin sheathed cable that’s excellent when you
want a reasonably heavy duty cable that looks neat and unobtrusive. For example,
I’ve used this cable under the bonnet of cars to power accessories. Just cut off the plugs and then put the cable aside until you need it.
Many VCRs use steel shafts as the hinge pivot in
their loading drawer. The shafts are precision machined (usually 4 or 4.5mm in
diameter) and can be threaded with a die, used as hinges or even simply bent to
form strong hooks.
These rubber drivebelts (usually one per VCR) are also worth
salvaging. I have used them as replacement belts in other machines but my major
real-world use has been as gasket rubbers, when I’ve wanted to seal around the
top of a box or even inside the front of a bike headlight.
Conclusion
The trick with salvage VCRs is to quickly pull the
thing apart, sort and keep the good bits – and then get rid of the rest.
If you’re the type of person who sees
possibilities when confronted with useable parts, there’s plenty to inspire
inside a VCR...