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Feature by Julian Edgar There are so many useful parts just waiting to be collected in the consumer goods that people throw away. Here’s what to look for. SALVAGING PARTS T he electronic equipment I build seems to use a lot of cooling fans and heatsinks. Those heatsinks range from the small ones that cool individual transistors up to those that are 200mm or more in length, while the fans go from tiny ones to 150mm in diameter. The good news is that, over the years, I have paid nothing for any of them! It isn’t just fans and heatsinks. I also get free plugs, sockets, switches, bearings, stepper motors, mains filters and IEC sockets... the list goes on and on. The trick is to salvage parts from the electrical consumer goods that others throw away. Let’s look now at some of the most productive discarded goods to salvage. There are warnings for some items, so make sure you read them before doing any disassembly. Photocopiers Photocopiers are always worth salvaging, and the bigger they are, 54 Silicon Chip the better. I once saw a huge Kodak commercial printer advertised free of charge. I just had to take it away. I knew it was going to be big, but when I broke a sling trying to hoist it onto a trailer with my engine crane, I thought I was defeated. The company was so eager to get rid of it that they agreed that I could dismantle it in their car park. I could take what I wanted and put the rest in their skip (it was too big to fit in the skip without being pulled apart). I still marvel at the quality of components that I got out of that machine. But let’s get back to more normal size photocopiers... The quality and number of useful components that you’ll find in a photocopier depends a lot on the specific machine. Unfortunately, there’s no way of knowing until you pull it apart. Some photocopiers have as many five DC brushless fans, while others have only two. Some photocopiers have large Australia's electronics magazine stepper motors but other use synchronous AC motors, which are much less useful. Then again, finding out what you’re getting is part of the excitement of salvaging parts from discarded equipment. You’ll find lights and fans inside all photocopiers. The lights are high-­ voltage, high-power incandescent filament bulbs that are used both to 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 neons or low-voltage LEDs. The fans consist primarily of conventional PC-type fans; they often run from 24V but they’ll work down to 12V without problems. Sometimes, if you get lucky, you’ll find a bunch of high-flow squirrel-cage fans. These are most often mains-­ powered, but a few work on 24V DC. siliconchip.com.au A typical older photocopier, partway through disassembly. Photocopiers are always worth savaging for their parts; the larger the machine, the better. You’ll find lenses, front-faced mirrors, low current and heavyduty switches and often good quality stepper motors. Three stepper motors (bottom) and an AC motor with a built-in reduction gearbox (top) salvaged from a photocopier. The AC motor had an output shaft speed of just 53 RPM, making it ideal for spinning an advertising sign or the like. Two cooling fans, LED lights and incandescent lights. The latter can also be used as high-power resistors. All photocopiers contain at least one very sharp lens. They are ideal for use as close-up magnifying glasses. There is a lot of salvageable hardware inside a typical photocopier, like springs, pulleys, machine screws and self-tapping screws. You can also be guaranteed to find an excellent quality lens (typical focal length: 180mm) and several mirrors. The lenses are razor sharp and make ideal hand magnifying glasses. They’re large and bright, and some are coated for better light transmission. The mirrors are front-faced and of a length that corresponds to the width of the photocopy area. Typically, they’re 10 to 20mm wide, so they’re long and narrow. 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 a very low-cost, high-quality mirror, there are plenty waiting for you! siliconchip.com.au 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 motor buried in that part of the machine. However, occasionally you stumble across gold – huge stepper motors with built-in reduction gearboxes. These are highly prized (and if you don’t want them, you can make a good profit selling them). They can be used to drive robots or three-axis milling machines, or be driven backwards and used as surprisingly powerful alternators. There are two completely different classes of switches that you’ll find Australia's electronics magazine in a copier. The most numerous are the tiny tactile PCB-mounted press-­ buttons mounted behind the membrane keypad. If these are extracted from the PCB by using a heat gun directed at the solder side, while at the same time a pair of pointy-nosed pliers is used to pull them out, many can be salvaged in a very short time. There will also be another pair of high-current switches: 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 July 2025  55 Micromite-Explore 40 October 2024 Complete Kit SC6991: $35 mind. If it was recently powered or you aren’t sure, use our Capacitor Discharger (December 2024; siliconchip. au/Article/17310) to make sure they are fully discharged as soon as you can access them. This list of parts hasn’t been exhaustive – I haven’t mentioned the LED displays, the electromechanical counter, the electric clutches, bearings or shafts. There are usually plenty of good bits to salvage. 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. used it as a cooling spray on a turbo car intercooler! Washing machines siliconchip.au/Article/16677 Coffee machines Includes the PCB and all onboard parts. Audio Breakout board and Pico BackPack are sold separately. You wouldn’t normally think of looking inside a discarded espresso coffee machine for good parts – but, in fact, there’s a bunch of useful goodies inside. In addition to switches, pilot lights (sometimes neon, sometimes LED), stainless steel fasteners and normally closed temperature switches, there’s the pump – and what a pump! Coffee machines contain a mains-­ powered oscillating (sometimes rotary) water pump that is capable of very high pressures – over 15bar (218psi). These pumps are fantastic where you want highly atomised water – just use high-pressure hose and fittings to attach the pump to a good quality brass misting nozzle. You cannot run the pump continuously (it gets too hot), but if you cycle it on and off, it will be fine. When salvaging the pump, don’t forget to also get the rubber mounts on which it sits – in operation, these pumps vibrate at 50Hz. I’ve actually run one of these pumps from an inverter and Washing machines have changed a lot over the years. Whereas once a typical washing machine was a top-­loading, belt-driven design with mechanical timer controls, machines now include technology like directdrive motors, fully electronic controls and plenty of wiring. Those aspects make any washing machine built in the last 20 years worthy of salvaging for its internal parts. All washing machines have a powerful electric motor inside. Most machines are belt-driven; that is, they use an electric motor that’s easily removed and can then be used as a standalone motor to drive anything you want – from a workshop sander to a fan. If removing the motor, don’t forget to also get the start and run capacitor, if fitted. Some washing machines – notably Fisher & Paykel designs – use a very special, large diameter, direct-drive motor. These can be removed, complete with the stainless-steel shaft and bearings, and then used as a wind generator, water generator, or even brushless DC motor. We described how to convert one of those motors to a generator for a windmill in the January 2005 issue (siliconchip.au/Series/84), and how to use one as a motor in February 2012 (siliconchip.au/Article/766). Even if you decide you don’t want it, these motors are worth money second hand. The electric pump from a washing machine is usually quiet, relatively low power (30~40W), can handle hot Metric stainless-steel cap-screws salvaged from a coffee machine. You pay real money for stainless steel fasteners like these, but here they were free. A microswitch, two normally open temperature switches (107°C) and a DPDT mains relay rated at no less than 16A, all hidden in a discarded coffee machine. worth salvaging; they are heavy duty with typical ratings of 16A at 250V AC. Cautions When you’re pulling apart a photocopier, you need to be careful of a few things. Disassemble the copier outside while wearing old clothes – inevitably, toner will get everywhere. 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. Other copiers use small gas struts – another excellent salvage part. The high-voltage power supplies have onboard capacitors that could give a nasty bite – they’ll be fine if the copier hasn’t been powered-up recently, but keep the potential in Inside discarded coffee machines you’ll find a very special pump. An AC design that oscillates at mains frequency, the pump produces very high pressure (over 15bar) and is safe to use with water. 56 Silicon Chip Australia's electronics magazine siliconchip.com.au If you can get them for nothing, washing machines are well worth pulling apart for their components. The water-control solenoids from washing machines are worth salvaging, especially if they’re 12V designs. Like the one shown at upper right, however, most are mains-powered. These LEDs, pushbutton switches and the rotary encoder were salvaged from the control panels of just two washing machines. All washing machines contain mains-powered pumps as shown at lower right. They’re quiet, use little power, can handle hot water and have removable filters. water and has a removable lint filter. These characteristics make the pumps excellent for circulating water in a solar water heater or for low pressure water transfer. However, if using a pump in this way, always ensure the wiring is appropriately insulated and Earthed and that water cannot come in contact with it. There are two (sometimes three) solenoids in each washing machine. These are electrically operated valves that control water flow. Most washing machines use mains-powered solenoids, but some use 12V solenoids. The solenoids can be used whenever mains-pressure (or lower) water supply needs to be switched on and off. The lower-voltage solenoids can be easily and safely used to control siliconchip.com.au water flow in a variety of applications, including solar water heating systems, gardening or recreational vehicles. They will cope with high water pressures and are usually leak-proof. The mains-powered solenoids should be used only in insulated surroundings. Old washing machines use a mechanical pressure switch to detect the water level. The water level adjustment is achieved by altering the spring preload. These switches are simple to use, high current, very sensitive and are always worth salvaging. An example use is for warning of a low water level in a rainwater tank. More modern washing machines use variable output electronic water level sensors. That sounds good, but most of these sensors appear to use an iron Australia's electronics magazine core moving within encapsulated electronics and I haven’t found an effective way to interface with them. Many washing machines now incorporate heater elements to allow higher water temperatures than can be provided by the domestic water heater (and/or to allow a single cold water hose to be used). These machines use a temperature sensor to monitor the water. These sensors are excellent parts to grab, being of stainless-steel construction and with quite a quick reaction time. They use an NTC thermistor, where the resistance falls as its temperature rises. As such, they are suitable for temperature sensing in a range of applications. Most electronics in washing machines is ‘potted’ – that is, the boards are covered with a thick layer July 2025  57 of rubbery plastic, waterproofing them. It’s pretty well impossible to salvage components from these boards. However, the control panel is usually not potted. By placing the control panel board in a vice and using the heat gun approach described earlier, it’s possible to salvage parts in literally seconds. Parts likely to be available include LEDs, switches and rotary encoders. There is a surprisingly large amount of hardware in many washing machines. Much of it is of high quality: stainless-steel self-tapping screws, heavily plated machine screws, and – in front-loaders – many long self-tapping hex-headed bolts (they hold the drum halves together). Because the washing machine tub needs to cope with out-of-balance loads, most machines also incorporate springs to allow tub lateral movement (top loaders) or vertical movement (front-loaders). These springs are heavy-duty and a well worth salvaging. You’ll also find a variety of rubber hoses and spring clips. Finally, there’s usually plenty of wire of different gauges and colours – perfect whenever you need a short length of hook-up wire. Video cassette recorders VCRs were once among the most numerous of electronic consumer goods being discarded. Now, they’re becoming much rarer, but they do still sometime pop up as giveaways. Contrary to what you might expect, the best bits are mechanical rather than electronic. The pick of the bunch is the video drum assembly – I am happy to pull apart a VCR just for the video drum. Why? It contains a precision-ground, hardened steel shaft. It also uses two precision sealed ball bearings that perfectly match the shaft. You also have two light alloy housings, one of which is normally a press fit on the shaft and the other that houses the two bearings. Finally, there is a brass collar with a grub screw that fits perfectly on the shaft. In almost any application where you need small bearings and a shaft Shown in the left photo is the rotating video head from a VCR. Even the cheapest VCR has a good-quality spinning assembly, and in disassembling over 50 VCRs, I’ve yet to come across one with worn-out bearings. At right, the video drum from a VCR contains precision matched components, including a hardened steel shaft, two bearings and two alloy castings. The brass collar, complete with retaining grub screw, is a tight fit on the shaft. Top: PCB-mounting RCA sockets salvaged from a VCR. Right: a sensitive wind vane that uses the components from a video drum for its rotating bearing. 58 Silicon Chip Australia's electronics magazine siliconchip.com.au or axle (robotics, a wind vane, small wind generator, model car etc) these parts can be used. Furthermore, as they’re pretty well standard across all VHS VCRs; if you need two axles (or four bearings etc), just keep collecting! In addition to the video drum, inside a VCR you’ll also typically find small springs, switches, wire-wound resistors and RCA sockets. You will also often find a 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 merrygo-round for a model railway layout or kids’ toy. Cordless drills If VCRs are now getting scarce, the same can’t be said for cordless drills – they seem to be thrown away in their thousands every week. At the tip, at garage sales, even in kerbside rubbish pick-ups; there are now always plenty of defective battery-powered electric drills. You might even have one or more broken cordless drills tucked away at the back of your workbench. Cordless drills usually have a maximum speed of 1000RPM or even less. To reduce the speed of the DC electric motor, and to increase the torque, a planetary gearbox is used. In fact, most often there are two planetary gearsets back-to-back – rather like the gear systems used in traditional automotive automatic transmissions. And like automotive transmissions, some cordless drills let you select between ratios – more on that in a moment. For their size, planetary gears are very strong and, especially when two sets are used, allow high reduction ratios to be achieved in small volumes. Considering their size and torque capacity, these are really nice little gearboxes. The torque multiplication might be achieved by the gearbox, but if you want to be able to quickly drill holes – or screw screws – you need power. It’s provided by a high-current DC brushed motor. Brushless motors are now available in electric drills, but I haven’t seen many yet on the discard pile. Typical drill motors draw around 10A at 12V when stalled, and considering they are about the size of a D cell, that’s a powerful motor you’ve siliconchip.com.au A discarded battery-powered drill contains a powerful low-voltage, brushed DC electric motor and a compact but strong epicyclic gearbox. Many also contain a PWM speed controller. The epicyclic gearbox. Many drills use two geartrains mounted back-to-back, while some allow two different gear ratios to be manually selected. A brushed electric drill motor being driven by a crank placed in the chuck, making a low-voltage hand-powered generator. Over 2.5W is easily available, so a powerful LED can be driven, or via a 5V converter, a phone charged. Australia's electronics magazine July 2025  59 Top ten parts to salvage We’ve been looking at the parts you can salvage from specific pieces of equipment, but you can turn the process around and look at the best parts to get. Here are the top ten. 1. Knobs Whenever you see a piece of equipment with quality knobs on it, grab them! It takes literally seconds to pull knobs off, and it makes such a difference when you’re building a project if you can just go to your storage drawers and immediately lay your hands on a knob that’s just perfect for the application. It’s also interesting sorting through different knobs and feeling the way in which they work – some knobs (eg, amplifier volume controls) need to be large and smoothly contoured; others (like the adjustment knob on an electronic thermostat) need to be small and much better shaped to suit fine adjustment. 2. Switches A switch is one type of electronic component that doesn’t go out of date. Over the years, I’ve collected switches from: ∎ VCRs (miniature pushbuttons, microswitches and the contactless Hall Effect switches often used on the video drum chassis) ∎ photocopiers (the switch that deactivates the power when the lid is raised) ∎ old electric typewriters (typically, the main on/off switch is a quality pushfit rocker design) 60 Silicon Chip ∎ amplifier input selectors (a multipole rotary switch) ∎ old washing machines (the water level switch – a very sensitive pressure switch) ∎ miscellaneous heavy duty equipment (high-current switches) All are useful and, even better, easy to use. 3. Cable clamps, mounts and holders Whenever you run wires or cables around inside a piece of equipment, there’s a need to hold them in place. Inside commercial equipment, you’ll find the full gamut of cable and wire holders – bendy insulated metal strips, steel clamps, plastic clamps, clamps that pop into chassis holes and clamps that hold mains-power cables. It’s always worth collecting these. 4. Fuses Fuses are another example of a component that doesn’t date – a 50-year-old glass fuse and holder are just as useful today as back then. As a matter of course, I collect fuses from all sorts of equipment. If the fuse holder is inline or an easily removed chassis-mount design, I collect those too. You can also obtain very useful fusible links from car fuse and relay boxes, and much industrial equipment contains resettable circuit breakers. I also collect the two different sizes of blade fuse used in vehicles. It is not at all hard to collect enough fuses that you’ll never need to buy one again – or Australia's electronics magazine spend the time travelling to the shop to buy that required obscure value. 5. Relays Relays are extraordinarily useful – rugged (basically impossible to blow up unless you do something really stupid!), universal within voltage and current restraints, and easy to wire up. An enormous range of equipment and appliances have relays inside – you can easily collect one from every even moderately complex bit of gear you salvage. Commercial equipment often uses solid-state relays, and I remember picking up the ABS (anti-lock braking) controller from a car and realising with joy that it contained no less than six small high-current 12V relays! 6. LEDs The idea of salvaging LEDs from equipment can seem silly – why bother when LEDs are so cheap new? First, it’s easy to salvage LEDs you cannot readily buy in shops – those with odd lens shapes (eg, long rectangular types) and LEDs with unusual colours. Second, using the heat-gun-and-­ pliers approach mentioned above, it takes almost no time to salvage dozens of LEDs. I often use shop-bought LEDs in projects, but nearly as frequently, I’ll want something out of the ordinary and reach for my little drawers of salvaged LEDs. siliconchip.com.au I come across – they’re amongst my ‘most-­utilised’ salvaged parts. 7. Plugs & sockets If you’re trying to find the right plug for a socket (eg, a DC socket that requires the correct mains adaptor), a visit to an electronics supplier is often required. If, on the other hand, you’re building a piece of equipment and need a similar function low voltage DC plug-andsocket combination, it’s often much easier and cheaper to use some that you’ve salvaged. For example, I often use RCA-style plugs as low-voltage DC power connections – they’re polarised, non-shorting and can handle reasonable current. You can salvage RCA sockets from any audio or video consumer item that’s been thrown away. The plugs are almost as often discarded on audio interlink cables! 8. Heatsinks Heatsinks are available in discarded goods in a huge range of sizes – from small ‘tab’ style ones in power supplies to large heatsinks in audio amplifiers, and every size in between. When building projects, it pays to have a large variety of heatsinks on hand. That’s because there is often not only a requirement for heat handling but also physical requirements as to size and shape. For example, space might be tight in one direction, or the flat mounting surface on which the components are to be mounted might need to be a certain shape. I collect all heatsinks that siliconchip.com.au 9. Small motors Many items that people throw away contain electric motors. Bread makers use mains-powered universal brushedtype electric motors; electric typewriters, printers and fax machines use stepper motors; and VCRs contain small low-voltage brushed motors. And as we’ve seen, washing machines and other larger goods contain mains-­ powered induction motors. I tend to collect just the following motors types: small low-voltage brushed motors (good for making fans and kids’ toys), and large and small stepper motors (good for robots, model railways and hand-cranked generator projects). Motors (of any sort) that can be removed complete with reduction geartrains are always useful. 10. Fans Cooling fans inside discarded equipment come in all shapes and sizes. PC-style fans can be found in PCs (yes, really!) and photocopiers. Fans with removable blades can be salvaged from microwave ovens, but open a microwave only if you know exactly what you are doing – they can be very dangerous. Squirrel-cage fans are used in much industrial equipment, as well as some types of domestic heaters. Fans are typically either mains-powered or run from 12V or 24V DC. Considering the cost of new fans (especially large ones), real savings can be made in this area. Australia's electronics magazine got your hands on – especially since it cost nothing! Many cordless drills have an electronic variable speed function, achieved by pulse-width modulating the power feed to the motor. The switching transistor is mounted on a separate interior heatsink and the rest of the control electronics are integrated with the trigger switch. A reversing switch is often mounted directly above the speed control. Even if you grab just this bit, you have a high-current, low-voltage electric motor speed control (or light dimmer etc). Finally, most of these drills have an adjustable slipping clutch that allows the peak torque to be set before drive ceases. There are plenty of uses for these bits and pieces. One of the easiest is to simply pull the body of the drill apart (because they are low voltage devices, tamper-proof screws aren’t fitted, making it really easy) and cut the wires at the motor. Bend a piece of steel rod into a crank-shaped handle and lock one end in the chuck. Turn the handle and you have a powerful small DC electric generator. How powerful? On one unit I measured, it was quite easy to run a halfamp load at 5V – that’s 2.5W. 2.5W is plenty to run high efficiency power LEDs, or even work through a 5V regulator to charge a phone. If you pick a drill that has two user-selectable gear ratios, it works even better. In one ratio, turning the handle is easy, but the amount of power generated is lower. Or, you can slide over the gear selection lever and have around twice the power output at the same rotational speed – but, of course, it will be much harder to turn the handle. The motor/gearbox/clutch/chuck assembly can also be used wherever a high torque output, low-voltage mechanical drive is needed. For example, two of the assemblies can easily be combined to form the individual wheel traction motors for a small robot (or use four for the ultimate in manoeuvrability!). Alternatively, the assembly can be used as a small winch, eg, to hoist a model railway baseboard up near the ceiling when it isn’t being used. In these applications, the built-in slipping clutch is a real asset, as it stops the motor from being overloaded when SC the output is stalled. July 2025  61