A basic, sub-$1,000 3D printer that prints metal | Hacker News Reader

A basic, sub-$1,000 3D printer that prints metal

gigaom.com

87 pointscdvonstinkpot33 comments

This article adds little value to the story, and it's difficult to locate the indiegogo link on that page.

Here's a direct link to the project: http://www.indiegogo.com/projects/minimetalmaker-a-small-3d-...

Anybody have a feel for how strong the "clays" are compared to ABS as well as the actual metals?

Mechanical engineer here.

Metal clays have been around for a while. Physical properties depend greatly on the base metal used and the temperature and environment in which the clay is fired.

Compared to "regular" metal, the clays will be significantly weaker, especially in tensile or shear loading. Not so much under compression.

So what about firing process for the printer? The video don't show the finishing process. Is this heating table?

> The device prints with a commercially available jewelry product known as "precious metal clay." This material is a pre-mixed emulsion of metal particles in a water soluble organic binder. When heated in a kiln (600˚C-900˚C) the binder burns away as the metal particles fuse together.

process is the same as for firing metal clay objects you might make by hand in a jewelry studio. Let it dry, program kiln to the specs given with the clay, and fire for 2 hours.

would they exceed 5000 psi in compression? and what drives the cost up? I noticed they have a steel clay. Is that real (ish) steel and could it be made for under $5 per pound (as a bulk material)?

The process is expensive because it's a very low volume product and it's a heterogenous mixture that needs to be stored and processed without separating, rather than an alloy. It has been possible to print with metal clay for a very long time, with every paste extrusion setup made so far, the major problem is material cost and firing. I don't expect an object made with metal clay to handle 5000psi in compression, but it might be possible with some clever geometry. The major issue with metal clay is that is behaves like clay in many ways, severely limiting geometry that can be fired without breaking. You can think of it as very high viscosity solder paste.

True, I don't think anybody will be printing toaster ovens this way. The plastic/elastic properties of metal does make metal parts printed this way quite different in performance from parts printed in plastic. Not to mention the temp. ratings. Purity stamp for silver PMC after firing is 99.9%

Steel clays need to be fired in an oxygen-free environment or you'll have major oxidation problems. I don't realistically see this ever becoming a thing.

>5000 psi

Possibly. Again, it depends on the metal you use. With the right steel or aluminum alloy I could imagine seeing something on this order.

Have been working with a pottery studio that does quite a bit of reduced-firing for special types of glazes. The clays that require low-oxygen to be fired can be embedded in special types of activated charcoal & reducing agents within the kiln. We've had some excellent results with bronze, have yet to try iron & steel. The firing instructions on those clays are similar to the bronze, however.

Related, from earlier this year on patents expiring: http://qz.com/106483/3d-printing-will-explode-in-2014-thanks...

All the objects in the video look very... rough.. so i don't think i'd buy that (and to actually print metal instead of plastic would be the only reason for me to buy a 3d printer).

Agreed. They are rough, not bad for a prototype i built on salary of a part-time library employee ;-> The quality will certainly improve. I have demonstrated proof of concept & have clay trace widths down to 450 microns. I have been able to print mini clay pots up to 25 layers tall. Clay blend formula is current topic of R&D. The essential challenge is to extrude with thick enough clay that it does not slump, yet thin enough to fuse together as it dries. -david

I don't think this will sell. You can use a cheap printer to print wax in a better resolution. And this printer also needs post processing just as the lost wax method.

Firing a kiln is far easier, and safer, than running a [home-]foundry. You can buy a kiln that plugs in the mains and sits on your desk or a small kiln that goes in your microwave oven.

printing in wax works great, but then you have to do lost wax:

1.attach sprues, 2.invest inplaster cast, 3. wax burn-out in kiln(which you still need), 4. centrifuge cast (with torch & crucible) 5. cast removal, 6. sprue removal (with saw, file) 7. fine clean-up (with dentist tools, fine files) 8. Surface finish.

With metal clay, you print, clean up like clay greenware, fire, and polish. equipment: printer, kiln, polishing misc.

If any of you guys are interested, there are some good discussions going on about this on Reddit. This one has been on there the longest, but it just got put on the sub reddits Technology and realtech as well.

http://www.reddit.com/r/3Dprinting/comments/1qrnjl/the_mini_...

http://www.fool.com/investing/general/2013/11/16/the-mini-me...

>But maybe crazy fine resolution isn’t as important for metal.

I'm trying to think of any practical application for which fine resolution isn't more important for metal than polymer

Nobody's asked how much the "ink" costs? I have a feeling this is the kind of stuff that makes inkjet ink sound cheap.

no story yet where you can print metal's gun?

At this point in technology its a lot easier to make those using subtractive (traditional) machining rather than additive machining. Ask any gunsmith. You'll get into all manner of weird definition games, like the legal one for print your own is making a lower receiver, so are you cool with buying a COTS barrel and everything else but the lower? Or you want to make that stuff too, well, OK, are you cool with COTS firing pin and other very minor componenets? Or are you cool with buying plain old screws from home depot or do you insist on making those homemade too?

http://mashable.com/2013/11/11/3d-printed-metal-gun/

There are already metal printing processes which can manufacture firearms. Still expensive though. Its relatively straight forward to build a black powder musket in your garage though.

That story just never made it to the front page.

https://news.ycombinator.com/item?id=6694279 (5 days ago)

Is there printer that can print itself?

It's the goal of the opensource RepRap project. To produce a pure self-replicating device. http://reprap.org/wiki/RepRap

I get tired of this, it's not even close to self-replicating... it can only print a few plastic joints it needs, but most of it is metal, electronics and motors that cannot be 3d printed.

I hope we will be able to do it soon. When we see all these awesome kickstarter projects and all these millions $ invested in R&D. I think we will reach soon another level

Wow. We are closer to future than I thought. Thanks for the link!

I also try to regroup all the 3D printers here : https://thre3d.com/category/printers check it out, maybe you'll need one!

No, but printers can print their clone ;)

Not all of them, and I was asking is there some progress in this area. I wonder if I'll see a factory-less society and how it will look like.

Reply on news.ycombinator.com