Friday, November 10, 2017

The end of CNC?

Well, this is interesting:
Desktop Metal, based in Boston, USA, has opened up pre-orders for its Studio System which uses inkjet-like technology, rather than laser-based techniques, to produce precision metal parts. 
The system isn't cheap – it's $120,000 to buy outright or $4,000 a month for 36 months – but compared to other ways of producing metal parts, especially in small numbers, it could be a game-changer. Sure, there are traditional CNC machines but they still cost from thousands up to hundreds of thousands of dollars. This fat gizmo is supposed to be a challenge to that. 
The printer will be made available in mid-2018, at which point the company hopes to expand even further with a production version of the machine that offers 3D printing at 100 times the speed and a twentieth of the cost of current systems.
It may be that this doesn't replace CNC, but rather traditional heavy manufacturing tooling:
One of the investors in the company, managing partner of BMW iVentures Uwe Higgen told The Register that the car manufacturer has warehouses full of tooling equipment for its different cars, each of which typically costs millions of dollars to create. It also takes months for those tools to be developed.
Interesting that BMW is investing in this.


Irish said...


Tim Wolter said...

Ah. The kicker is the price of the materials. Might come down. But just as companies pretty much give away printers and make all their money selling you ink cartridges, so it is at the present time with metal 3D printing.

You also have to be mindful of the degree of precision that can be attained in the real world. CNC can nail things down to thousandths of an inch. 3D printing is basically a computer controlled hot glue gun.

No doubt Star Trek replicators are going to happen. But I think the time frame is longer than hyped.

T. Wolter

SiGraybeard said...

The end of CNC? Doubtful. Certainly not now.

In terms of comparing prices, it's meaningless to not have work envelopes and speed of operations to compare the two because that's the difference between a $10K CNC center and a $100K.

It's better to think of conventional milling as subtractive manufacturing and 3D printing as additive. Both can do many things, but they each have strong points. It's a heck of a lot easier for AM (additive manufacturing) to make something that's hollow with some web of reinforcement inside than it is to start with blocks of metal and hollow it out.

That said, I still think that even a relatively crude metal printer, I'm talking .005" tolerances, at household appliance prices could be a really big game changer. Imagine printing out a piece of sheet metal for your car, or the frame of a 1911.

We can get into "steel isn't steel isn't steel" some other time. ;-)

Eric Wilner said...

The technology resembles the first non-SLA 3D printer I ever saw demonstrated; that one, if memory served, was spitting wax binder onto a bed of corn starch.
3D printing of metal isn't going to replace CNC for most volume applications, but it has interesting potential for doing things that CNC just can't - like fabricating objects with internal chicken-bone structures for improved strength at minimal weight, or objects with impossible-to-machine cooling passages (I'm thinking rocket combustion chamber, nozzle, and cooling features all fabricated as one piece, with no welding, and maybe the head and injectors could be included).
...And now I'm thinking of Jordin Kare's pair of songs, "The Designer" and "The Engineer". Now if they can make it, they'll do it by luck, for it can't be held with a dog or a chuck...

libertyman said...

Machining has changed, and will continue to do so. This will add another way to manufacture some things, but machinists will evolve and the requisite skills required will evolve as well.

Ted said...

Not all Tooling is the same. Big difference between some punch press that needs to crank out a whole bunch of brackets that will be shared between a number of different production lines and the 100 TON SHEET METAL stamping press that makes left rear fenders. Both are Tooling, 3D printing of parts might replace the punch press ( but only when it can match the speed and cost -- good luck with that any time soon). But replace stamped body panels - nope, those will all be molded composite. but the molds and the dies maybe made by 3D printing.

And those warehouses the article talks about are full of dies, so no difference there. Thoose dies are made of hardened steel for a reason. I doubt the output of the 3 d printer can stand up to the needs of a stamping die.

Mr. Engineering Johnson said...

As others have noted, I'm doubtful about this ending CNC. It's far more likely to be a useful adjunct to existing processes. If I were to gaze into my crystal ball, I would say the big impact will be on economy of scale.
Machining from billet often removes more material than it keeps, making it wasteful for large production runs. Pattern making and casting take skill and time so they are inefficient for small numbers of parts. 3D printing helps fill in gaps by making it easier and quicker to make casting patterns or make blanks for finishing by more conventional machining. As quality improves and cost goes down you will see this as a step in the manufacture of many products.