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Review by Nicholas Vinen We’ve looked at 3D printers in the past but this one is different – you can buy it right now and have it up and running an hour or two after it arrives. You can design objects with 3D CAD software and then watch as they’re turned into “the real thing” before your very eyes! UP! 3D Printer 86  Silicon Chip siliconchip.com.au 3D printers have come a long way in the last few years. They are no longer just curiosities. Nor are they so expensive that they’re way out of reach. Nor are they the monsters of yesterday. Recently we were given the opportunity to evaluate a desktop-sized 3D printer from Intellecta, the Australian reseller. It’s the UP! 3D Desktop Printer and it measures just 240(w – plus 55mm for the media roll ) x 195(d) x 340(h) mm, with a weight of 5.2kg. That makes it small and light enough to fit just about anywhere. First impressions count! The first impression we got upon removing the printer from its packaging is that it is a serious piece of gear. The main part of it is made from powdercoated steel and feels hefty and solid. The stepper motors and gearing are clearly designed for precision; there’s no backlash in it at all. The maximum object size that can be created, 140 x 140 x 135mm, is set by the size of the printing platform and the range of the axes. However an object that large (or anything close to it) would take many hours to print and as we shall see later, must be carefully designed if it is to be printed without distorting. On the other hand, smaller objects such as knobs, gears and so on print relatively quickly and there’s no real trick to it. Once the printer has been set up, you just feed the 3D models into the software, press the print button and away it goes. You can print multiple smaller objects in a single print run if desired. The printer’s resolution is excellent, with settings of 0.2mm (fine), 0.3mm (normal) and 0.4mm (fast). This allows for smooth curves and makes relatively fine detail possible. Objects printed at the higher resolution settings naturally take longer to produce. Roughly speaking, printing a small object takes an hour or so while several small or one medium-sized object will take 2-3 hours. Larger objects will take proportionally longer. One very good feature is that the entire print job is stored within the printer’s memory before printing begins, allowing you to unplug and shut down the host computer while the job continues. This is handy for those larger jobs. ABS plastic The objects produced are surprisingly strong and rigid for their size and weight. Acrylonitrile Butadiene Styrene (ABS) plastic is used as the print medium and when this hardens, it is quite tough. Flexible sections can be made by carefully controlling the thickness and fill density but sections with higher volume feel solid (even if they are filled with a dense mesh, to reduce weight and save on material) The white plastic is semi-translucent so thin sections are translucent, to a degree. This presents some intriguing possibilities, for example where LEDs could be installed inside, to use as indicators or to create a piece of art. The standard plastic reel is white although differently coloured filaments should be available soon. Just to emphasise that this printer has practical uses, some of its own parts are printed on another (identical) printer! (You can print a set of spare parts in case one of them breaks). One of these parts has an actuator arm which bends to trigger a microswitch, demonstrating the (ahem) flexibility of the printer. While the printer does most of the work to produce 3D objects, there is some manual work to complete them. Just how much work is involved depends on the shape of the object and specifically how many holes and overhanging sections it has. This is because the printer can’t deposit plastic in mid-air; the liquid plastic would distort with nothing to support it. So where there is a hole or overhang, it is automatically filled with a sparse plastic lattice. This is dense enough to support the plastic above but much less dense than the object proper and so can be broken or cut away relatively easily. Sometimes adjacent areas require some sanding or filing to clean them up once these sections have been removed. Similarly, the entire object is built on a plastic platform (which ensures a level base for the object, regardless of the smoothness of the actual platform) which must be separated from it when it is finished. This is usually pretty easy because the join between them is not very solid and it is perfectly flat, so once you get a utility knife blade between the two it’s a simple matter to slice them apart. Software Recognise it? It’s the 3D printer at right but in this case it’s a printed version, in ABS plastic, done by the 3D printer at right! siliconchip.com.au The STL file format used is a standard 3D printing file format that can be August 2011  87 produced by many 3D CAD (computer aided design) packages. For the printer to do its job, the 3D model(s) must be converted to a series of thin horizontal slices (with a thickness defined by the print resolution). These slices are shaped by the motion of the x and y-axes in combination with a motor in the print head controlling the rate at which the plastic filament is extruded. Once the slice is complete, the printing platform moves one step lower and the printing of the next layer begins. The steps required to convert a 3D object into slices and to define the nozzle movements and extruder control are complex, especially when the object has holes or overhangs, as the printer can’t simply deposit plastic into thin air. Even for simple solid bodies, the printer moves in intricate patterns, defining the outer boundaries of each slice before filling the internal diagonally. Each layer is built up with a different orientation than the layer below, for maximum strength. Luckily this is all hidden from you and so you don’t have to concern yourself with the details since the software works this all out (although watching the printer work is quite fascinating). The PC software which accompanies this printer is excellent. It is fast and easy to use. Once the printer is calibrated, all you really need to do is import the STL file(s), let it lay them out on the print platform and then tell it to start. Once the job has been processed and sent to the printer, it warms up the printing platform and also the nozzle to its operating temperature (260°) before proceeding to print. There are some settings which control the process of converting the objects to slices, in case you need to tweak it for your particular application. For example, you can set the maximum angle of overhang before supporting “scaffolding” is built below it. We generally left the printer at its default settings as these seemed to work quite well. Operating details All three axes are controlled with stepper motors. For the x-axis, the nozzle moves left-to-right along a channel at the top of the printer. For the y-axis, the printing platform is moved in and out (ie, front to back). For the z-axis the platform itself is raised and lowered, moving it closer to and further from 88  Silicon Chip The 3D print can be secured to the base by paint supplied with the unit or can be printed onto another base secured to the machine’s baseplate. We found the second option much easier and resulted in less problems with image distortion. the nozzle, which is at a fixed height. The axes are automatically “zeroed” by the printer, using internal microswitches which activate when it reaches the end of its travel along an axis. The printer runs the stepper motors through their full range before printing, so that it can zero each axis. They are controlled so accurately that it can then run for hours without having to re-zero them; it uses relative positioning for the entire print job. The extrusion head contains a heater, motor, fan and control electronics and is connected to the printer with a ribbon cable. The heater maintains the nozzle at 260°C during operation, melting the ABS plastic filament that it pulls in using an internal motor. The fan runs constantly, keeping the motor and control electronics cool despite the adjacent hot nozzle. By adjusting the motor speed, the printer can control the rate at which plastic is extruded. This is important, not only because it needs to feed it at a different rate depending on the printing resolution but also since some objects require the nozzle to be lifted and re-positioned periodically and the extrusion is temporarily halted as it does so. The 1.75mm diameter plastic filament that the extruder consumes comes off a reel on the side of the printer. There is second small motor mounted just above the reel which feeds the filament to the print head. The way it does this is quite ingenious. The plastic travels from the reel, up through a hole in a flexible plastic arm and then through a clear tube to the print head. As the head pulls the filament in, this causes the clear outer tube to press down on the lever arm at the other end of the tube, triggering a microswitch which feeds more plastic off the reel and so relieves the pressure on this arm. This printer generates a fairly strong aroma of hot plastic while it is operating so it’s probably a good idea to run it in a well-ventilated area, away from where people are working. In terms of noise, it’s clearly audible when printing but not too distracting. As well as motor noise, the fan in the print head is quite audible. Printing platform The printing platform is quite critical to the operation of this printer and it is something of a paradox. The deposited plastic must stick to it in order to avoid deformation in the object being printed but it can’t stick too well or it would be too hard to remove when the printer is finished (and doing so might damage the platform and/or the object). To solve this, the printer comes with a jar of green latex paint. The ABS plastic sticks to the paint well but the paint layer is quite thin and flexible so the object can still be removed. Some of the paint usually peels off along with it, so it must be frequently re-applied. A much better solution, according to the distributors, is to clip a section of perforated prototyping board (perf board) to the printing platform with small bulldog clips. It’s then quite easy to remove the printed objects and it doesn’t need as much maintenance; we much preferred this method. (Obviously you can also easily unclip the perf board if you need to remove it; a less messy procedure than repainting the platform). You can also use a specific type of masking tape (3M brand). This is mentioned in the manual but we didn’t try siliconchip.com.au Getting down to the nuts and bolts . . . these actually work, the internal and external threads mesh perfectly and could even be used in a non-critical application. The “lacework” underneath is the base on which the parts are printed; this is easily cut away when they are separated from the base plate. Once the platform height has been set correctly, the nozzle is then lifted up slightly and moved into each corner of the platform in turn. By observing how the clearance changes, you can see whether the platform is level and if not, adjust the screws holding it. As it is moved closer to level, the clearance can be reduced. Eventually the nozzle will “hover” just above the printing platform as it moves around and then you know it is perfectly level and so objects can be printed accurately. The printer is then ready for use. As for maintenance, it is occasionally necessary to clean any plastic off the print nozzle which may have stuck to it but it doesn’t appear necessary to do any periodic re-calibration (although this may be useful in the long term). Power supply & accessories it since the perf board solution worked quite well. The platform can be removed from the printer by removing two screws. This is necessary after printing onto latex paint, since it can take quite a bit of force to remove objects printed on the paint and doing this could otherwise upset the printer. Platform heating Another issue with the platform is that it must be heated. If it weren’t, the deposited plastic would cool too rapidly and the resulting object would be badly distorted and poorly formed. This is most critical with larger objects since they take longer to print and their corners are further from the platform heater, in the middle of the platform. We found this to be the single biggest challenge when printing objects with large footprints. If the corners lift off the platform due to uneven contraction of the cooling plastic, the object being printed can distort. The solution is to design the object with “feet” or risers on the bottom, to lift it up so that even if the plastic in the corners distorts, the distortion only affects the “scaffolding” of plastic below the object and doesn’t distort the object itself. This helps whether the feet are part of the final object or are designed to be removed later. The bottom line is that larger objects must be designed with the limitations of the plastic material in mind if they siliconchip.com.au are to be printed flawlessly. Set-up and calibration This 3D printer doesn’t need much in the way of calibration; it is calibrated before being sent out and it tends to retain its configuration well during transport. If you want its output to be exact, there are some additional calibration steps in the manual. Some assembly is required when the printer is delivered. It comes in five main pieces: the X-Y-Z rig, the printing platform, the print head, the plastic feed mechanism and the reel and holder assembly. Putting these pieces together is fairly easy and takes about fifteen minutes. The parts are held together with hex head screws (Allen keys provided). The critical part is getting the printing platform level and calibrating the nozzle height. To do this properly it’s necessary to remove the part of the XY-Z rig which holds the platform and change how it is held in place. This procedure is detailed in the manual. Once it’s complete, the platform can be attached and it can then be levelled with the aid of a computer. The first thing to do is use the computer to command the platform to move towards the nozzle in smaller and smaller increments until there is just 0.2mm spacing between them. This is how printing starts and so the printer needs to be able to move the platform to the correct height each time. The version of the printer we received for review had three separate power supplies but in the latest version (being sold now) this has been reduced to two. The large “brick” type supply provides 20V at 11A, for driving the motors and heaters. A separate 5V supply drives the motor which feeds the filament to the print head. The printer we reviewed had a second 5V supply for the printer’s electronics but this has now been combined with the motor/heater power supply. A USB cable is supplied for connection to the host computer. A large range of accessories is provided, including practically everything you need to use the printer. In addition to the printer and the items mentioned above, you get: • Allen keys and spare machine screws (for assembling and calibrating the printer and for removing/ reattaching the platform). • One 700g reel of ABS plastic. • Knife and side-cutters (for removing support components of printed objects). • Tweezers, gloves, spatula, paint. • Instruction manual. Consumables The ABS plastic the printer uses comes on a 700g reel. At the time of printing, replacement reels cost $70 plus GST. A 700g reel lasts a long time; you can print scores if not hundreds of objects with a single reel (depending on their size and density). We didn’t even use August 2011  89 a quarter of a reel during our testing, which was fairly extensive. As mentioned earlier, reels of coloured plastic are coming soon although each object will have to be printed in a solid colour. With the latest version of the software, it is now also possible to print using a biodegradable plastic made from corn. If this plastic is being used, the nozzle temperature is reduced since it has a lower melting point. Uses One obvious electronic-themed use for this printer is to produce bespoke knobs, mounting hardware, extension shafts, bezels and so on. It could be useful for producing items for rapid prototyping and also for those who restore older equipment (eg, vintage radios) where replacement parts may not be available. With some careful design it may even be possible to make small prototype enclosures and other components, for prototype evaluation. It’s good to be able to check that everything is going to fit before ordering a large production run. It could also be used to produce gears, gearboxes, arms, levers and so on for robots or robotic vehicles. The ABS plastic is both light and tough so gears made from it should be able to transmit a fair bit of power (although there will obviously be limits). Another possible use is to make carriages and miniatures for model railroads. Indeed any model-making exercise would benefit from the ability to make custom-shape parts and perhaps even entire miniature models. And yet another which springs to mind is in marketing and presentations: imagine, for example, the impact of an architectural firm presenting their building design to clients – and then handing each client an accurate, detailed, scale model of that design! Or perhaps a product designer doing the same with a new product which the client can actually feel, turn upside down, look into and so on. The possibilities are endless and the costs of production are minimised. Having seen the miscommunication with offshore manufacturers (especially where language is concerned!), a 1:1 model could be sent with the order, saying “it should look like this!”. They’d have to make sure the finished product wasn’t produced entirely in 90  Silicon Chip ABS white, though! (Don’t laugh... we’ve seen worse!) Conclusion While this is an intriguing product and it clearly has many uses, 3D printing isn’t the sort of thing that you can take on lightly. There is a learning curve to operating it if you are to get consistently good results. Fortunately, Intellecta and 3D Printing Systems have the knowledge and experience to help those new to 3D printing figure it out. We were impressed by the quality of the engineering in this unit and the thought put into the hardware and software. It is quite mesmerising to see 3D objects that you just designed appear out of what seems to be thin air. Many of the objects we printed during our evaluation period were downloaded from a free website called Thingieverse (www.thingieverse.com) and this is a good place to get example models and see what is possible with a 3D printer. Price & availability The UP! 3D printer sells in Australia for $3532 plus GST and comes with a 12 month warranty. For more information, contact Intellecta at support<at> intellecta.net or call (08) 8351 8288 (South Australia). Visit their website at www.intellecta.net. In New Zealand contact 3D Printing Systems on (09) 281 4205 (Auckland) or 3dprinting. co.nz You can also visit http://3dprintingsystems.com where you can see videos of the printer in action, see sample printed objects and even request a sample (mention SILICON CHIP). SC Printing 3D chocolate . . . would that be to your taste? As this review was being completed, a news release appeared which gives 3D printing a whole new flavour – literally! It has absolutely nothing to do with the machine under test but we thought it interesting enough to add a bite. While still very much in prototype stage, researchers at the University of Exeter Photo: EPSRC (UK) have produced a 3D Printer which uses chocolate as its medium, rather than ink (or in the case of the printer reviewed, plastic). Specialist retailers are reported to be very excited about the 3D Chocolate Printer and have already started making enquiries about getting their hands on one. “Imagine a customer coming into your shop, selecting a design on a computer – or bringing in their own – and walking out with that design in chocolate,” said one. Operation is quite similar to the printer reviewed, in that the 3D image is built up layer-by-layer. The tricky part is to get the temperature right to print the layer of chocolate and then make it harden enough for the next layer to first of all attach but just as importantly, to not distort. It’s not the first time edible printer media have been tried – in 2010 researchers at the University of Cornell (USA) used liquefied foods Screenshot by Christopher MacManus/CNET as the ink in a 3D printer. siliconchip.com.au