A HOME STEREOLITHOGRAPHY PRINTER AT A GREAT PRICE

In our last post we talked about a new development that allows ultra-fast 3D printing using stereolithography. It’s probably going to be a while before you can get this technology in a home printer, of course, but if you like the idea of stereolithography itself that’s certainly something you can get. We’ve been checking out a great example of a home stereolithography printer, the affordable and surprisingly sophisticated ELEGOO Mars.

First of all, why would you want a printer like this? They do have a couple of quirks that make them slightly less user friendly than filament-based designs – you need to wash off excess resin with isopropyl alcohol, and most types of resin need an extra bake with UV light after that to finish the curing process.

On the other hand, this technology is generally faster than the more common fused filament deposition. It usually produces stronger prints, without the risk of layers separating. Stereolithography prints are strong enough to be machined without delaminating, which makes them ideal for structural or mechanical parts. Finally, they seem to give much better results with translucent or transparent materials – the layers are much less obvious. If these features are important to you the ELEGOO Mars could be the printer you’re looking for.

The Review

At £229.99 on Amazon the ELEGOO Mars is right at the lower end of the price bracket for resin printers – making it a tempting choice for beginners – but the build quality was a surprise. It’s a solidly made little unit that feels like it should last, and it also comes mostly assembled. Set it up on your desk – it has a nice small footprint and a solid all-metal base – mount the UV shield and you’re pretty much good to go. It’s literally a five-minute job.

One slightly tricky thing is keeping the print bed level. This has a ball mount that’s billed as making it easy to level. It’s not bad, but it does tend to drift a little between prints, so it’s best to check it every time. Luckily that’s a matter of slackening then retightening the levelling screw with the bed at zero elevation.

Once that’s done all you have to do is fill the resin tank and load your print model. A USB port at the back lets you do this via a memory stick, controlling the job through the clear, bold 3.5” touch screen. The built-in operating system is simple to use, too, so you can get your print job underway quickly and easily.

Then you’re probably going to sit there for a bit, scratching your head and wondering if it’s actually working. This printer is seriously quiet, especially if you’re used to a filament-fed one. That’s probably because there are a lot fewer moving parts. The print bed rises steadily out of the tank as the job progresses but there’s no nozzle shuttling around all over the place. Instead, as the bed takes each step up, the resin below it is illuminated in one exposure by the 2560×1440 LED array under the tank.

Print speed is surprisingly high. The bed moves at 22.5mm an hour, and with a print volume of 120x68x155mm it can turn out a full-volume print in a bit under seven hours. That isn’t bad at all, especially when you consider the quality of the print. The time it takes to do a layer is pretty consistent too.

As for print quality, once you’ve learned the quirks of a resin printer you’re going to be amazed at what the ELEGOO Mars turns out. The high-resolution LED array means the X and Y axes are capable of 0.047mm resolution, and they do that very crisply. The default layer thickness on the Z axis is 0.05mm but you can bring that all the way down to 0.01mm if you want. Even on the default, though, you’ll get amazingly precise prints with none of the issues that can appear with filament.

Of course stereolithography does have some issues of its own. Unless you hollow out your prints – which is easy to do with the included ChituBox software – you can get through a lot of resin quickly. When you’re hollowing things don’t make them too thin, though, or the walls have a habit of collapsing. Adding some supports is a good idea. Also, when you’re hollowing things make sure there’s some way for surplus resin to drain out or you can get some suspiciously liquid-filled objects.

The Verdict

As a way to get into stereolithography without breaking the bank, the ELEGOO Mars is pretty hard to beat. The printer itself is affordable but well made, and turns out prints to a much higher quality than you’d expect in this price range. The resin is reasonably priced too, at under £30 for a litre. It comes in a decent range of colours, too. You don’t get the same range of material options as you would with filament, but if you’re looking for high quality, robust plastic prints this neat little printer is a great place to start.