If you’re a PC modder, or if you’ve ever wanted to print small objects that you just can’t find anywhere else, 3D printing can be very useful. Antony Leather looks at what types of printers are available, how to design and print your own objects, and why owning a 3d printer can be worthwhile.
While they’ve yet to become as popular as inkjet printers, 3D printers have certainly captured a lot of headlines recently. Sending design files for wrenches into space for astronauts to print out is all very well, but many printer manufacturers would also really like to see their machines in the home, in the hands of hobbyists. The machines are certainly becoming more affordable, with DIY kits now available for less than £250.
Ratherthan just being the latest must-have gadgets, though, 3D printers are genuinely useful tools for all manner of tasks. We've seen plenty of PC modders using them to create parts for their projects, and in some cases, they've printed entire cases too. Not only that, but we’ve seen 3D printers used to create tools, adaptors and pretty much any object you can design in a rendering program.
Over the next few pages, we'll be looking at what types of printer are available, the costs involved, how to print an object and the ways in which 3D printers are useful for PC enthusiasts and modders.
Types of 3D printer
Most of the smaller 3D printers you’d want to use at home use plastic-based materials. The most common material (and certainly one of the cheapest) is PLA, which is bought in spools and fed into the printer. It’s then melted and extruded through nozzles before being laid down in thin layers, building up a 3D object. Many cheaper printers, particularly models that are available in kit form, use spools of plastic filament that cost around £20 per kg.
The number of objects you can make per spool will vary greatly depending on their solidity, but in general, a typical spool can create 40 or so matchbox-sized objects. The main differences between 3D printers that use plastic filament concern the maximum print size, the print resolution and print speed. Print sizes usually measure between 4in3 and 10in3 for a single object. Meanwhile, the print resolution is a lot like the resolution on your monitor - the higher the resolution (usually measured microns, where lower is better), the smoother the finish. For instance, a resolution of 200 microns results in fairly visible lines from the print nozzles, while a resolution of 50 microns results in a much smoother looking object.
The downside is that higher-resolution objects take longer to print, which is where time becomes a consideration. Some cheaper printers are capable of printing at fairly high resolutions, but even matchboxsized objects can take many hours to print out at these settings. Generally, the more expensive models offer larger print sizes, higher resolutions and faster print times.
Plastic filament printers are the most common models among hobbyists, but there are several other types too. Some use liquid resin that's cured by lasers and offers much higher resolutions than plastic filament printers, but these printers also cost a lot more both to own and operate. Companies that offer professional 3D printing services often use selective laser sintering (SLS) printers.
Print at home or away
While the cost of owning a 3D printer is now cheaper than ever, you may only want to print a few objects in one go, and not have a need to use a 3D printer again. In addition, you may need a high-quality or extra-large print that’s only possible to produce on a high-end printer that costs tens of thousands of pounds.
Thankfully, there’s one easy way around this dilemma. Numerous companies offer 3D printing services whereby you send the company a design file, and it will print your object for you. These companies can even correct errors with the design that could result in a failed print.
One such company is www.3dprint-uk.co.uk, which offers high-quality printing using an SLS printer with nylon. At 20p per cubic centimetre, the price is more expensive than printing the object on a PLA-based printer. This higher cost is partly due to the fact that it’s being printed at a higher resolution using more expensive materials, but also because this price is based on the total volume of an object. For example, if you print a hollow cube, you’ll be charged for the total volume, not just the volume occupied by the material. You also have to wait a few days for delivery.
How do you print an object?
If you've never set eyes on a 3D printer, you probably have little idea how the whole process works. Printing a 3D object is actually quite easy and not dissimilar to the process of printing a document on a normal inkjet printer. You create a file, upload it to the printer, adjust various settings and click the Print button. There isn’t much more to it than that. In the below example, we'll show you step by step how it's done with a standard 3D printer.
Download a prerendered STL file
Whether you’re uploading a file to your 3D printer or sending it to a company to print for you, the easiest file format to use is STL. Most 3D printers can print directly from these files, and all 3D printing services accept them too. There are two ways to create one.
You can download a prerendered STL file from a number of object databases, such as www.thingyverse.com. There are tens of thousands of objects available from these databases in a range of formats, including STL files.You just need to download one and upload the file to your printer.
Create your own design
If you can’t find a suitable file online or maybe one that needs reshaping a bit, we've included a complete walk-through in this month’s modding guide on how to create a 3D object using the browser-based design program TinkerCad (www.tinkercad.com). It’s fairly easy to use and is adept at creating text ad well as simple or detailed objects that are accurate down to 0.1mm. You can also upload files so if you find an object online, you can alter it to suit your needs.
If you’re already used to other 3D rendering programs, many can export your designs as STL files. Google’s SketchUp is free to use and more flexible than TinkerCad plus there are even more SketchUp-created files out there than there are on Thingyverse too. However, you'll need to add in the SketchUp STL extension in order to import or export designs as STL files. You can download it at http://tinyurl.com/sketchup-stl-plugin. One essential tool for the job of designing your objects is a micrometer, which you can use to take accurate measurements of motherboards or other components in order to create 3D designs.
Upload your design
Now you have your STL file, you need to upload it to your printer. This j ob can be done in a variety of ways. Some more elaborate printers connect to Wi-Fi networks, allowing you to print almost as easily as with a network-connected printer. Others require the file to be uploaded using a USB stick. The software varies depending on the model of printer you use, but even the cheap kit-based printers, such as those made by PrintrBot, include software that’s fairly easy to use.
Strength, fill and supports
With your design uploaded to your 3D printer, you now have to make a few decisions. There are several options concerning print resolution, density and strength that you need to consider, depending on the type of object you're making. If you’re printing an ornament, then you'll want to use a high resolution/low micron count. The printing software will show the resolution in millimetres, with the lower number representing the width of the lines used by the printer - the lower the width, the greater the detail, but bear in mind that higher-resolution printing takes longer.
If your object doesn’t need to be strong, and won't be stressed or bent, then you can use low density and simple fill patterns, reducing print times and using less material. With our example, a hexagonal fill pattern can be selected to provide the greatest strength, along with a strong density setting.
You also need to consider rafts and supports. As their name suggests, the latter are used to support your object, especially if it’s a top-heavy design or if it features overhangs. For example, if you printed a teacup, you'd want to print a support under the handle to prevent it dropping while it's printed-think of it as scaffolding for your object. In addition, if you're printing a large, solid and flat object, you may want to use a raft. This process involves creating a base for your object that’s printed beneath it, which can help to prevent uneven cooling of the object that can cause warping.
Finally, you need to prepare your printer for printing. It's always best to calibrate and level the printing surface first - the manual will advise you on how to do this job best for your specific model. You also need to apply an adhesive surface to the printing surface. Many people use painter’s tape, which allows the object to be easily removed once it’s been printed. It also helps to prevent uneven cooling, while providing an adhesive surface to prevent the object moving during the print. On the Cube 3 printer we’re using in this feature, you use a tacky glue that secures the object's base to the printing surface - you can then clean off the glue afterwards.
How much does it cost?
As we've previously mentioned, the cost of printing your object varies greatly depending on the design. If you're going to be printing a lot of objects then it’s worth considering the power draw of the printer too - plastic extrusion printers need to heat the plastic, and most medium to large objects take hours to print too. However, the key to keeping costs (and indeed print times) to a minimum is largely down to the amount of plastic you use.
As a result, if there are any locations where you can create spaces or gaps in your designs, rather than needlessly filling in unseen space, you should take every chance to do so, even if it means spending a little more time rendering them. For instance, if you're printing a cube-shaped object, don't fill in the entire cube, but create a hole in the middle. In TinkerCad, you can simply create a slightly smaller version of the cube, insert the shape into the centre of the original render, and then convert it to a hole.
For this reason, though, it can be quite tricky to work out exactly how much an object will cost to print. Cold, hard numbers point to a rough figure of 1cm3 of PLA or ABS plastic costing 5-10p, assuming you're using a standard 1 kg spool of plastic filament. However, there are exceptions to this costing rule, such as the Cube 3 printer reviewed in this feature, which uses more expensive proprietary cartridges, rather than standard filament spools.