Is this what we have been waiting for.

**LINK**

Oh, it'll continue to develop, all right; it's too good a technology for aerospace, F1 and all that not to have lots of money thrown at it, because it can produce all kinds of "impossible" things. Give it time, and Warco will be selling them...

As with all this kind of thing, you need to be able to create the object as a 3D CAD model first, and the rapid prototyping gubbins does the rest. Even then (see the way the propellor is located) you're often constrained by the way in which the model is created on the machine, so it's not simple even then.

Creation of complex 3D shapes on a computer is not simple. I know; I've been trying to do it professionally since 1995. When shapes get curvy (like motor cars, shoes, any kind of arty-farty sculpture), the digital definition of the shape of it becomes very tricky indeed. Modifying what you've created because it "isn't quite right" can be a nightmare - and as for trying to edit somebody else's creation - you'd often be better starting from scratch.

Luckily, most of "our" type of stuff was invented before about 1960, and is perforce usually defined fairly simply as far as 3D digital definition is concerned. Lots of simple flat shapes and relatively easy cylindrical bits more or less define a steam locomotive! Unless you want to re-create (say) a 1950 vintage motor car. Even then, if you have access to the real thing and a 3D laser scanner, you're laughing.

A New Zealand chap on another forum is building a 5"G BR standard 3MT, using 3D CAD to produce wax models of the castings, which are then cast in steel. It is looking absolutely superb - I think his cylinder casting includes some bosses which are not actually used for anything - but they appeared on the real one. And it's all hidden by the cleading afterwards...

The more technology improves, the more ways there are of making "models" or whatever it is you wish to call them. Some people embrace it, and create magnificent things of beauty which would be next to impossible to create using a treadle lathe and carbon-steel tools. Each to his own.

The idea could be combined with precious metal clay (PMC). Bronze, copper, silver (sterling & fine) as well as gold have been mixed up with organic binders to form a metal powder loaded clay-like material. This then is first heated in a kiln to burn off the binder (about 350C) & finally heated in charcoal to sinter the metal (about 860-890C for silver & bronze). Densities approaching 97% of the normal metal can be obtained. Shrinkage of approx. 10% occurs during firing.

My wife does quite a bit of jewellery making using this method, modelling the PMC in the same way as plasticine, then sintering into the solid metal. It works, and works quite well. The next stage is to use 3D printers to lay down the PMC instead of doing by hand.

Regards,

Richard.

I've been designing parts for direct laser sintering paid prototyping for several years now, and coordinating their builds. The parts vary from working metal parts to mould inserts 60 mm dia x 30 mm.

The parts were made by service bureaus , primary on EOS sinterstations. All were excellent, but there are some things that have to be understood about DLS in its' current state, and about the day to day operation of the machines. Accuracy is affected by many variables, mostly operator skill for settings and conditions. Finished size polished finish mould inserts for example are not yet possible, inserts are made slightly oversize and EDM'd to size and finish. One major benefit of mould inserts by this method is that cooling passages can be any shape conforming to the cavity, unlike conventional moulds with drilled passages. For working parts, warpage and surface finish ripples and roughness can be an issue on large flat surfaces. I have been told by two independent manufacturers of DLS machines that it takes 2 to 3 years of steady practice to develop operators that can consistently make parts to size and correct finish. It can take a few tries even for an experienced operator to make a tricky geometry or feature correctly. Post-printing sintering and heat treatment is very difficult to master and is the major determining factor in a part being on size and with warpage in spec.

The technology will of course develop and improve in future but I doubt that it will ever dominate the metalwork industry vs subtractive methods like CNC milling in combination with other processes. The main attraction of DLS is that parts with geometry that can not be made any other way, in some very exotic high strength steel and non ferrous alloys, can be made with DLS. JD

Interesting the way Fulop dismisses the failure of A123. They were riding a wave of government and private funding, had large corporations (and F1) beating a path to their door and still went bust having squandered hundreds of millions of $. They attracted their fair share of charlatans and BS artists who lived high on the hog (and their expense accounts). I've heard some truly jaw dropping first hand accounts of the staggering excesses that were commonplace there and also experienced the problems working with them myself, representing large corporate (potential) customers. Only in America...

He says the underlying cause was that batteries are a low margin product. I think the actual cause was something to do with the people running it, their vast egos and the mirage they were chasing. The US government also caused a battery bubble by investing billions in new battery factories that had no real market to serve. There were several other very similar companies that also went to the wall, although perhaps not in quite such style.

I'm always suspicious of these "serial entrepreneurs" who are great at extracting money from investors based on exciting patents and "MIT professors". Seems they often do very little else than raise money and blow it.

Murray

It would be slow, but what about combining a 3D printer with electrolytic deposition. Bang - there goes a multi-million dollar patent...

Neil

Anyone who designs a 3D printable wingnut by combining two disks with a stock nut, doesn't have the imagination to deserve the privilege of playing with such technology!

I am acquainted with the guy to whom you are referring. The accuracy of his models will come as slightly less of a surprise when you know he has an association with the team building the BR Standard Class 3 Tank at the Severn Valley Railway at Bridgnorth.

He is a master craftsman and he has the opportunity to get up close and personal to the piece parts during his visits.

Edited By Brian Oldford on 26/04/2017 17:44:09

.

... But I would have thought they might deserve the courtesy of a 'credit' for their image.

[unless of course it is yours]

MichaelG.

Needs to be more like a v shape, just like I thought.

the edges look so rough i'd almost call it a rasp, how to wear out any mating components in no time at all.

The other thing is that the basis for the technology in metal powders is already used in industry, except they don't need to print it, they just sinter it if they're looking for volume production.

The problem is when it comes to all kinds of steels, they are made in furnaces that need to reach thousands of degrees, and then go through a further tempering process in order to make them to spec, this is what gives them their enduring, lovable qualities of metal. 

Even in plastics, the rate at which cnc sliding head lathes can rip through bar stock kills it's appeal for quick industrial turnarounds, injection moulding (theres an American company I saw once that makes tiny super accurate injection moulded parts which have amazing level of detail). is also much quicker for larger components.

I can see why some remain doubtful for it's ability to revolutionize, they should get over the hype and see that although it's exciting, it's also a complimentary method not a "junk your old machines and all go with this" type of scenario. 

It's a bit like when tubal cain said we should junk all our old imperial machines because nobody will want to make the sizes any more, and they're still here funnily enough, and not too keen to go anywhere any time soon.

Michael W

Edited By Michael-w on 26/04/2017 19:20:50

" His task would be to convince attendees that spending $120,000 on Desktop Metal’s prototyping printer and sintering furnace is essential for the future of their companies." Good luck with that then!I feel another bankruptcy coming on, but who cares, he has lived well! Some companies exist solely to attract investment for research. My advice? Don't hold your breath!!

Siemens are already 3D printing parts for gas turbine engines only at the testing stage i think

It's from the article linked at the top of the thread.

They should get Matt Crawford in on sales

Neil

Actor or Archers!! I know which one you mean really, I also listen to radio 4 in the workshop!

Phil

.

Yes, I knew that

MichaelG.

So its a no then

.

Judged by the level of investment by interested companies, it's a technolgy they have been waing for.

**LINK**

https://www.desktopmetal.com/company/about/

**LINK**

https://www.desktopmetal.com/company/news/

Whether we could realistically consider waiting for it is probably governed by the odds of winning the Lottery.

MichaelG.

.

**LINK**

https://www.desktopmetal.com/products/production/

**LINK**

http://www.theverge.com/circuitbreaker/2017/4/26/15440744/desktop-metal-studio-printer-3d-printing-manufacturers

Edited By Michael Gilligan on 27/04/2017 09:05:55

If you are interested I just put a scan of the BS wingnut spec in my album. BS856 1969 taken from the BSI booklet issued at that date. Isn't it amazing what you have lying about!

**LINK**

:0)

Martin

Richard's (R&T) "clay" sounds interesting, if a printable version became available. The amount of shrinkage would make well toleranced 3D prints difficult but it could possibly be used to make one's own "castings" in bronze which could then be machined where necessary.

Rod