More Parts for Nothing!

Great bits for the inventive

by Julian Edgar

Click on pics to view larger images

At a glance...

  • Zero cost parts including:
  • Springs
  • Machine screws
  • Self-tapping screws
  • Precision shafts and bearings
  • Low power geared DC motors
  • Electronic components including miniature switches
  • Rubber gaskets
This article was first published in 2009.

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!

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...

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