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Salvage It! BY JULIAN EDGAR There’s lots of good bits inside junked photocopiers If you haven’t noticed, these days you can pick up used photocopiers for a pittance. Nope, not pretend little desktop photocopiers but the full-size office monsters that weight 40kg or more. Some are working, some aren’t – but when you pay less than $15, all are excellent salvage value! So what bits and pieces can you get out of a typical photocopier? ➊ ds a epen nts d re’s no e n o p e ll l com ely th usefu nfortunat til you pu but f o r e n – U b u . s t r m u ie an go er less f u’ve and n tocop stepp ality cific pho y what yo DC brush ve large ich u q e e h p ha ve Th ctl the s tors w piers ents g exa any fi lot on f knowin ave as m photoco us AC mo compon e d o h way rt. Some two. Som ynchrono e salvage use of the e h s a h it apa have only thers use lthough t ore), bec 10-$15. T t $ a m o e s n o e u h m j l a S c i . u so h er for ore th seful rs, w (or m moto uch less u orth $50 t spend m ht by tend o g are m be well w wise to n was bou t e r ’s h t e g i mi dh ty, rtain cture unce copier pi photo 0 $15.0 siliconchip.com.au ➋ Inside all photocopiers you’ll find lights and fans. The lights – high voltage, high power incandescent filament bulbs – are used to both illuminate the material to be copied and also as a heater to cook the toner as the photocopied sheets are on their way out of the machine. The latter light often includes an over-temperature switch mounted nearby. In addition, you’ll sometimes find rows of mains-powered neon lamps and/or rows of low-voltage LEDs. Fans consist primarily of conventional PC-type fans (although often running on 24V – but they’ll work down to 12V without problems) but sometimes – if you get lucky – you’ll find a bunch of squirrel-cage fans of the sort that move a lot of air very quietly. These are usually AC mainspowered but a few work on 24V DC. July 2006  73 ➌ You can also be guaranteed of finding an excellent quality lens (typical focal length = 180mm) and a number of mirrors. The lenses are razor sharp and make ideal hand magnifying glasses – they’re also large and bright and some are coated for better light transmission. The mirrors are frontfaced and their length corresponds to the width of the photocopy area. Typically, they’re 10-20mm wide, so they’re long and narrow. To be honest I haven’t found a lot of use for them (except, oddly enough, winding high powered resistors on them!) but if you’re into lasers or other optical systems and need very low-cost, highquality mirrors, they should do the job quite nicely! 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! 74  Silicon Chip ➍ Even if the photocopier’s main transport system is powered by an AC motor, there will still be a few low-voltage stepper motors inside. For example, if the copier uses a document feeder, there’ll be a stepper buried in that part of the machine. However, occasionally you stumble across gold – huge stepper motors (as big as a man’s fist) with built-in reduction gearboxes. These are highly prized (and if you don’t want them, you can make a good profit “eBaying” them) and can be used to drive robots or 3-axis milling machines, or they can be driven backwards as really “grunty” alternators. Alternatively, you may find an AC motor with a built-in reduction gearbox. The one pictured here has an output shaft speed of just 53 RPM, making it ideal for spinning an advertising sign or the like. Note that most of the extensive gear-train you’ll find inside a copier cannot be extracted whole – not unless you keep the complete chassis intact. Instead, look for sub-gear assemblies that mount on separate baseplates. ➎ There are two completely different classes of switches inside photocopiers. The most numerous are the tiny tactile PC-mounted pushbuttons which are located behind the membrane keypad. By using a heatgun directed at the solder side of the PC board and a pair of pointy-nosed pliers to pull them out, a lot can be salvaged in a very short time. There will also be another pair of switches with very different current ratings to the pushbuttons – the main on/off switch (normally on the back of the photocopier) and a pushbutton switch that goes open-circuit when the top half of the copier is pivoted up for repair or toner replacement. The latter two switches are definitely worth salvaging – they are heavy duty with typical ratings of 16A at 250V AC. siliconchip.com.au ➐ ➏ There’s also a w ho scrounging. The le lot of hardware that’s worth fo 2-position hinges ld-down lid often uses snap-act ion , there are hund re screws, many sp rings, pulleys, ca ds of machine bles and toothed and a bunch of cogs and gears. There’s also som belts, potentially even ething more useful – pa inted or plated metal brackets sheet and panels. Thes e to construct custo are ideal if you need m brackets, mak panel or similar. e And don’t forget a new faceplate very easy to rem th ove (do it first so e glass: it’s usually there’s less chan breaking it!). ce of ➑ Think “photocopiers” and you’re probably immediately thinking of high-voltage power supplies. After all, photocopiers use kilovolts inside! However, while the power supplies are able to be salvaged (most copiers have at least two HV power supplies), there aren’t too many practical uses for a power supply with an output of just 290mA at 5kV! In addition, there’s also usually a conventional linear power supply, typically providing 5.2V at 0.4A and 1.6A at 24V. If you decide to strip these rather than use them whole, you’ll find a range of medium and small aluminium heatsinks that are easily removed. Make sure that any high-voltage capacitors are completely discharged before touching them. When you’re pulling apart a photo­ copier, there are a few precautions to keep in mind. First, disassemble the copier outside while wearing old clothes – inevitably, toner will get everywhere. Second, some copiers use torsion bar springs to counterbalance the weight of the open top half. These springs are very powerful and if you undo their retaining screws while they’re under tension, they can fly out and possibly cause injury. Other copiers use small gas struts – another excellent salvage part. Finally, the high-voltage power supplies have on-board capacitors that could give a nasty bite – they should be OK if the copier hasn’t been powered-up recently but keep it in mind or you could get a nasty shock. siliconchip.com.au This list of parts hasn’t been exhaustive – I haven’t mention­ ed the LED displays, the electro-mechanical counter, the electric clutches, bearings or shafts. There are usually plenty of good bits to salvage. But even if you don’t keep a lot of stuff, pulling apart a photocopier is a fun exercise in itself. It’s fascinating to see how the engineers have fitted a complex machine into a compact package. ❾ July 2006  75