Exploring A New Frontier: Desktop EDM Is Coming

To say that desktop 3D printing had a transformative effect on our community would be something of an understatement. In just a decade or so, we went from creaky printers that could barely extrude a proper cube to reliable workhorses that don’t cost much more than a decent cordless drill. It’s gotten to the point that it’s almost surprising to see a project grace these pages that doesn’t include 3D printed components in some capacity.

There’s just one problem — everything that comes out of them is plastic. Oh sure, some plastics are stronger than others…but they’re still plastic. Fine for plenty of tasks, but certainly not all. The true revolution for makers and hackers would be a machine that’s as small, convenient, and as easy to use as a desktop 3D printer, but capable of producing metal parts.

If Cooper Zurad has his way such a dream machine might be landing on workbenches in as little as a month, thanks in part to the fact that its built upon the bones of a desktop 3D printer. His open source Powercore device allows nearly any 3D printer to smoothly cut through solid metal using a technique known as electrical discharge machining (EDM). So who better to helm this week’s Desktop EDM Hack Chat?

While Cooper is still riding high from the phenomenal success of the Powercore Kickstarter earlier this year, which brought in over $192,000, he certainly didn’t limit questions to his own project. He’s a firm believer in EDM, and whether you’re using his device or trying to DIY your own solution, he’s always happy to talk shop. That said, he did clarify at the beginning of the chat that the first wave of Powercores should be shipping before the end of July. The source for the project will be opened up around the same time as well, Cooper said it was important to the team that paying customers got their hardware before DIY clones started popping up.

Early questions in the chat focused primarily on the electrodes, which are naturally a very important element of EDM. As the sparks erode the workpiece, they also wear down the electrode itself. This needs to be compensated for during the machining process, or eventually the spark gap will become too great.

Luckily, a modified 3D printer has more than enough Z travel to counteract this issue. Cooper explains that they’ve prepared a special fork of the LaserWeb4 for use with EDM that will constantly lower the Z height at the proper rate to counteract the electrode itself becoming shorter over time. There was also discussion about electrode materials and shapes, including an interesting hollow variant that could have dielectric flushed through it while cutting deep holes.

While discussing what’s required to convert a standard 3D printer for EDM, Cooper explained that the process is quick enough that you don’t technically need a dedicated machine for it. This is made possible by the fact that, at least on the Ender 3 they’ve been using for testing, no firmware modifications are necessary. You simply remove the hotend and replace it with the electrode holder. That said, if you’re going to be doing a lot of EDM, it would make sense to have a dedicated setup, especially when you consider how cheap you can get an Ender 3 these days.

Eventually the discussion migrated towards the types of materials you can cut with a desktop EDM setup, and where the future might take things. Cooper says all of their testing with the Powercore has been with relatively thin aluminum, and indeed that’s all that’s been promised in the Kickstarter.

That being said, they’ve made progress with steel, though he thinks that switching the electrode from a brass rod to a thin wire is likely to be the key going forward. The far thinner electrode will cut faster, but the mechanics involved will be considerably more complex than simply bolting a brass rod to a 3D printer.

For one thing, the wire needs to be held in tension. That means it needs attachment points above and below the workpiece. The wire is generally kept moving as well, being pulled from a supply spool and getting wound around a take-up spool on the other end. None of this is impossible for a DIY machine, and we’ve already seen early attempts, but it’s going to take more work to make it practical on a hobbyist budget.

Which in the end, is sort of the point. By the end of the chat, which ran over two hours, the general feeling was that an exciting adventure was ahead. First generation DIY EDM rigs like the Powercore are only the beginning, not the final result. Once a few hundred hackers have these machines on their benches and can start working on them, it will pave the way towards the next evolution of the hardware. To put it another way, this is the Makerbot Cupcake era of home EDM — these are the days folks will look back on in 15 or 20 years as the first steps towards putting this powerful technology in the hands of the individual.

We’d like to thank Cooper Zurad for stopping by the Hack Chat, and wish him nothing but luck with the Powercore. We’re eager to see what the early-adopters will be able to do with the hardware, and also look forward to the design going open source so others can tweak and improve on it. There was a time when 3D printers and laser cutters simply didn’t exist outside of high-end R&D labs, and now we can pick them up on Amazon. It’s hard to say if the same will eventually be true for EDM machines, but we’re excited to find out.

The Hack Chat is a weekly online chat session hosted by leading experts from all corners of the hardware hacking universe. It’s a great way for hackers connect in a fun and informal way, but if you can’t make it live, these overview posts as well as the transcripts posted to Hackaday.io make sure you don’t miss out.