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Salvage It! BY JULIAN EDGAR So you’ve found a no-cost VCR – let’s salvage the good bits Rather than building a project, this month we’re going to look at the parts that you can easily obtain from a VCR. VCRs are now available for nothing or near-nothing – the one shown here was picked up at a garage sale for $5 but on kerbside hard rubbish collection days, they are free! But what good parts are inside? Contrary to what you might expect, the best bits are mechanical rather than electronic. Let’s take a look. ➋ ➊ , model machine n’t really S H V fi istar h del do t – a Gold the make and mo avy it is! in o p g n he rse, e starti nt is how are to ut of cou Here’s th 903CH. B at’s more importa more likely you s, the -F R r e b e h e th w m , num e – R tr h C x c e ry mu ier a V go to amount matter ve you see, the heav inside. In fact, to le ib d e r c in ll Huh? We eable components achines weigh an some fantastic m ag nd e fi p l ’l ta u . On the o o e y find salv switches noids inside atic vid d d -m n n a a U ) t s d n id e ie o ft sole anc olen be li otors and n barely -quality s (some ca g, including high ht VCR has few m his Goldstar unit T ig in ht want. engineer , a super lightwe g you mig d other han lly less of anythin ra and gene ling” in weight. d id was “m 82  Silicon Chip 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 job from start to finish. 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 placed to one side, the next step is to remove the tape transport mechanism and head. This assembly is almost always found on a sub-chassis which is screwed to the plastic inside the case. siliconchip.com.au ➌ Here’s the inner chassis on its own. At this stage, the contents of the VCR have already been narrowed down to just this and the PC boards. Throw the rest away as you remove it – ie, the top and bottom covers, the front cover and the inner plastic chassis. Anyway, the next steps involve pulling this piece of gear apart. You’ll need a good-quality medium point Phillips head screwdriver – invariably, some of the screws are tight and once you start mangling screw heads with a second-rate screwdriver, it rapidly gets too hard. Put all the screws, springs and drive belts into plastic containers as you proceed. ➍ And here ’s a whole V one of the pearls. I’ C good I th R just to pull this m happy collectin in g p drum ass k it is. But what is art out – that’s ho w embly tha it? It’s the t holds th write and spinning e e great pre rase the tape. It’s video heads that re cis d a life of the ion many million esigned to rotate w d, s V it Specifica CR and as a resu of times during th h lt, lly e steel shaft , its mechanicals it’s beautifully m ad co , sealed b all bearin mprise a hardene e. either an in g d with Alle terference fit to th s, brass fittings (th n-h ey e support fr ead grub screws) shaft or are secure ’re a need sma me. In almost any and a diecast allo d y ll a vane, sm bearings and an a pplication where all wind you xle (robo g tic en parts can be put to erator, model car, s, a wind use. Wha well stan t’s more, etc), these da they’re p need two rdised across all rett V a collecting xles (or four beari HS VCRs, so if you y ngs, etc) ju ! st keep o n ➎ Here’s what we have so far. At top left is the disassembled drum assembly. In the centre at the top are 10 springs (nine extension and one compression), while below that are 38 machine screws and 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, Phillips head self-tappers in stock? Or a fine metric-thread Phillips head machine screw – just what you might need one day as a replacement in a piece of gear you’re working on! At top right is a DC brush-type permanent magnet motor which uses a worm gear to drive an output shaft. It would make a perfect winch for a model boat, or it could be used to slowly rotate a display. siliconchip.com.au Rat It Before You Chuck It! Whenever you throw away an old TV (or VCR or washing machine or dishwasher or printer) do you always think that surely there must be some good salvageable components inside? Well, this column is for you! (And it’s also for people without a lot of dough.) Each month we’ll use bits and pieces sourced from discards, sometimes in mini-projects and other times as an ideas smorgasbord. And you can contribute as well. If you have a use for specific parts which can easily be salvaged from goods commonly being thrown away, we’d love to hear from you. Perhaps you use the pressure switch from a washing machine to control a pump. Or maybe you salvage the high-quality bearings from VCR heads. Or perhaps you’ve found how the guts of a cassette player can be easily turned into a metal detector. (Well, we made the last one up but you get the idea . . .) If you have some practical ideas, write in and tell us! December 2005  83 ➐ ➏ Remember the PC 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 low-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’m likely to have a use for and which cost more than just a few cents to buy – parts like the colour-coded RCA sockets, the high-power wirewound resistors and the high-value, small package capacitors. And forget the soldering iron. All you do is secure the PC board in a vice, aim a heat-gun at the solder side and gently pull on the component you want to remove with a pair of pliers. Using this method, it takes just a minute or so to salvage 10 or 15 components – and that’s time worth spending. These are ju minutes w st some of the comp ith a heatonents tha g t 0.22F sup er-capacit un yielded. They in a few or clu torches), fi ve micro p (great for human-po de a wered LED ushbutton LED bargra sw p high-powe h display, nine RCA itches, a 2-channe l r resistors sockets an .N capacitors d that also to ot shown are the 20 three Incidentall ok only m electrolyti o y, c componen what you don’t no ments to remove. w do with ts is put th these em in a “ju readily ac ce n through a ss them when you n k box”. If you can’t kilogram eed them of (a way to fin d them!), y assorted componen nd sorting ts is not th o in multi-c u ’l l n e v e ru e om plastic com partment plastic tr se them. Instead, in ve ay p and be sure onent drawers to st s or a small set of c st le ore your c to clearly omponents ar label the d rawers. ➑ Also collected was an infrared pass filter (this photo was taken through it!), a smoked plastic bezel, some high-power diodes, a drive belt and a heatsink. And there were heaps of bits I chose to throw away – the mains power cord, a metal sheet with punched ventilation holes (ie, the undercover), the rubber feet and so on. In fact, the components that I salvaged can be cupped in two hands – and that’s good! Good because it takes little room to store them and good because only the most valuable bits were kept. So the next time you see a VCR on its way to the tip, take a moment to think whether you could use any of the components inside it. The Latest From SILICON CHIP Completely NEW projects – the result of two years research & development • • • • 160 PAGES 23 CHAPTE RS From the publishers of Learn how engine management systems work Build projects to control nitrous, fuel injection and turbo boost systems Switch devices on and off on the basis of signal frequency, temperature and voltage Build test instruments to check fuel injector duty cycle, fuel mixture and brake and coolant temperatures Mail order prices: Aust. $A22.50 (incl. GST & P&P); Overseas $A26.00 via airmail. Order by phoning (02) 9979 5644 & quoting your credit card number; or fax the details to (02) 9979 6503; or mail your order with cheque or credit card details to Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. 84  Silicon Chip Intelligent turbo timer I SBN 095852294 - 4 9 780958 522946 $19.80 (inc GST) NZ $22.00 (inc GST) TURBO BOOST & nitrous fuel controllers How engine management works siliconchip.com.au