Engineer creates a 3D metal printer prototype for $2 using electroplating | Hacker News Reader

Engineer creates a 3D metal printer prototype for $2 using electroplating

3ders.org

37 pointspraptak11 comments

> It is a 3-axis CNC machine combined with an electroplating head.

Erm... CNC Machines can cost thousands of dollars. I think this guy made a $2 attachment to a CNC Machine that then spits out copper.

Which is cool and all, but the headline doesn't seem right to me.

Yes, and the very first picture shows that amongst the additions is an HP lab power supply worth well over $200 second hand.

Not necessarily. Conventional CNC machines are expensive because they have to a) do accurate positioning while b) subjected to the large deflection forces involved in conventional machining. There are no such forces in electroplating.

The head control steppers in a printer would be more than accurate and beefy enough for this job, if you don't have to worry about deflection. Three of 'em, and you've good to go.

For that matter, you can buy turnkey 3D printers for less than a thousand bucks now. There's no reason you couldn't attach an electroplating head on one of those in place of the standard head.

> high amount of energy required to 3D print a metal object

I'm very curious how the energy efficiency compares to other methods of production. After reading this[0] article I've become highly suspicious of how easily the energy footprint seems to be overlooked in maker cultures.

[0] http://www.lowtechmagazine.com/2014/03/how-sustainable-is-di...

>That’s right, just $2. No zeros in sight!

Hmm, let me see if I can find those zeroes...

>his 3D metal printers could be sold for between $1,000 to $2,000

There they are!

Which seems to be the universal price range for entry level 3d printers.

How long does it take?

Let's see.

Copper has valence 1, that means that one atom is deposed by each election that flows on the system. A mol of copper has 63g, thus, for each 100,000C that flows, there'll be 63g deposed. The video says it uses 100mA of power, what makes it capable of deposing 63µg/s at most.

Serious galvanoplasty power supplies start at the 50A mark for a reason.

Doing a bit of in-my-head math... At 1A, that'd be about 50g/day.

I don't remember the voltage required for electroplating using CuSO4+acid, but I remember it being low. I suppose it probably has to do with electrode spacing too. As a guesstimate, let's go for 5 volts (which I have no idea of the accuracy).

If we're stepping household 120V down to 5V, we've got a factor of 60 reduction. With a (big ass) buck converter, we can in theory get 15A*60 = 900A = 900C/s out of a standard breaker. That works out to 49kg/day? That seems ridiculously large. I'd love for someone to point out what I did wrong though. I've assumed 100% efficiency everywhere, but even cutting it down to 10% still results in ~5kg/day.

Edit: I'm sure it's an expensive power supply, but it's nice to see that I got in the right ballpark: http://www.americanplatingpower.com/reverse-pulse-power-axd-...

> With a (big ass) buck converter, we can in theory get 15A*60 = 900A = 900C/s out of a standard breaker

No way you're gonna run 900A through this little pencil - the temperatures at contact point will act like a welding machine (uncontrollably melt/vaporize)...

Indeed. You can probably run a lot more than normal if you keep the tip submerged and circulate the electrolyte, but you're not gonna run 900 amps through it.

Some useful equations and numbers here:

http://www.ami.ac.uk/courses/topics/0223_plate/index.html

Reply on news.ycombinator.com