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con-pilot
25th Jul 2011, 17:27
I find this completely mind boggling. (For those that know me here, this is hardly surprising.)

But is this for real or not?

‪3D Printer‬‏ - YouTube

chuks
25th Jul 2011, 17:34
They now have a way to make a 3-D model from a set of numbers. Basically you have this polyester goo that you shoot laser beams into to selectively harden it. You then wash off the unhardened goo and what remains is the shape of the part that had only existed in the computer as a digital file!

There is much more to it than that but I think that is the basis of it; the answer to your question is that, yes, this is a real technology that is now in use, not a joke at all.

Krystal n chips
25th Jul 2011, 17:37
They also make 3D tools....very useful at 00silly hours on a cold, wet, windy, freezing ramp in the middle of January.....:hmm:

Um... lifting...
25th Jul 2011, 17:40
Oh, yes... very real. The real trick is matching the strengths of current conventional materials. That's coming with aligned crystals of ceramic and metals, as well as powdered metals heated in plasma.

Absolutely amazing what they can do these days. Think of powder coat paint... same basic idea, except you coax a material into a shape and cure it to optimize its physical properties.

con-pilot
25th Jul 2011, 17:40
Perhaps that science fiction 'transporter' nonsense, as we had assumed, is not all that much nonsense after all and such technology maybe closer than we think. Perhaps not in my lifetime, but.....

Very interesting follow up, thanks Chuks.


We're a bit out of touch here in Oklahoma, many here are still trying to figure out that new fangled thing call the 'wireless'. :p

sitigeltfel
25th Jul 2011, 17:42
I think the first part of your name gives us a clue, Con-pilot :ok:

The big test would be if it could replicate itself.

OFSO
25th Jul 2011, 17:44
Friend of mine is building one, here's the link to what he wants to build

TechZoneCommunications.com LLC (http://www.techzonecom.com/gglrrk)

He called it a reprap machine.....my wife's dentist used a similar device last week to build her a temporary crown (for her mouth, not head: I am Queen OFSO).

con-pilot
25th Jul 2011, 17:56
The 3-D printing concept I understand, but to make a working part/unit/thing from just scanning the object is what I find so interesting. The second video shows the parts being made, then assembled.

Lon More
25th Jul 2011, 18:01
Very much infant technology although it has been around for several years. The surface texture srill tends to be ridged, although this can be much improved using much finer resolution on the steppers

con-pilot
25th Jul 2011, 18:05
Very much infant technology although it has been around for several years. The surface texture srill tends to be ridged, although this can be much improved using much finer resolution on the steppers

Like I said, we're a little out of the loop technology wise here, but just as soon as the telegraphy wires are strung, we'll be right up there. :\

OFSO
25th Jul 2011, 18:08
The great thing is that like Linux, it's out in the world of hobbyists and enthusiasts now and who knows what will come of it ? Just lets keep MS away from it !

chuks
25th Jul 2011, 20:50
CNC milling has been around for quite a while now. That lets you turn a block of material into a finished shape, working from digital file, a sort of 'virtual part' that serves as the template for the real part. (Check out the gearbox on a diesel engine for a DA-42, when you can see the characteristic fine lines left behind by the bit from the CNC milling tool.) This enables us to make extremely complicated shapes much more easily than in the past, when you needed a genius running a milling machine to do much less. Too, these parts are full-strength, where the new 3-D plastic ones are the right shape but may not be usable as such if what you are looking for is a piston for an engine, say.

It is always interesting how some genius comes up with something that someone else quickly uses to make something rather trivial. In this case, have a look at these new paperweights you can buy, with a little Lear Jet (or in the case of one famous aviator we know, a Leer Jet) made of tiny dots of white inside a clear glass cube. That is done with two laser beams that collide and interfere to cause local heating and fracturing of the glass, I think. This is the same basic principle used to make the 3-D parts from the magic goo, except that the toy is just a framework of little spots trapped in the clear glass matrix. Anyway, you can imagine from seeing the toy how the 3-D shape is achieved.

tony draper
25th Jul 2011, 21:06
I have a clip of a CNC milling machine making a engine block from a solid lump of aluminium I assume, absolutely fascinating,tiz on youtube somewhere.
The Book of Enoch the Mad states in verse seventeen of the third thorus,
'And it came to pass in those times that the talking monkeys were be able to work wonders just before they become extinct'.
:uhoh::rolleyes:

OFSO
25th Jul 2011, 21:34
the talking monkeys

Would that be in Hartlepool by any chance, Tony ?

Pitts2112
26th Jul 2011, 00:30
3D printing, also known as "rapid prototyping" has been around for at least 15 years that I know, but my experience with it was only static parts, not assemblies or moving parts, and they were very fragile. It looks like the technology has moved on a bit since then.

Hydromet
26th Jul 2011, 00:33
Hobby versions of the machine are now available in kit form. D1 & her hubby (ubernerds) bought one. It can make things about 6mm^3.

G-CPTN
26th Jul 2011, 00:41
GU32Q6QXtWQ

pigboat
26th Jul 2011, 01:15
They also make 3D tools....
Pretty soon men will be completely superfluous. :sad:

Bushfiva
26th Jul 2011, 02:11
I got the Z650. I guess you can say it works as advertised, if you can afford the running costs. It's possible to print functional items such as the demo Brain Gear: it works straight from the machine, and doesn't require assembly. It's also colored in the machine using bog-standard HP printer cartridges but not HP ink: the first thing the machine does when you insert a cartridge is to suck all the ink out of it and throw it away. On the input side, I also got a 3D scanner which can to pretty spectacular things.

The hardness of the final product depends pretty much on how much effort you're prepared to put in: air drying, water spray, painting with superglue and immersion in superglue, in order of ascending strength. Other printers can use elastomers: at least one university is using such a machine to print single-use soles for running shoes. I'm not aware of anything that can actually "print" a functional item such as a spanner, that could actually be used to tighten bolts. But one can get pretty close. Of course, you can also print molds suitable for casting.


‪Brain gear machine‬‏ - YouTube

ChrisVJ
26th Jul 2011, 02:56
I saw a demo on the idiot lantern the other day. They scanned and then made an adjustable wrench. The interesting thing was the wrench was made fully assembled and adjusted right out of the powder. It obviously wasn't as strong as the real thing but they did use it to turn and tighten down a nut more than finger tight.

Arm out the window
26th Jul 2011, 04:05
It's an amazing thing to see.

One thing I couldn't work out from the video of the bloke scanning and replicating the shifting spanner was how that scanner thing they used could see 'inside' the mechanism - I'd have thought they'd have to take it apart to scan all the bits (screw thread, sliding jaws etc) that were hidden from sight.

Does anyone know how that part works?

Henry09
26th Jul 2011, 04:10
seems a good thing to buy some shares in!

Ian G
26th Jul 2011, 04:22
It's clever but it's clearly not the same wrench. Some of the previous posters are entirely correct - you can't scan what you can't see. The moving parts on the other models are made possible because they are designed as being integral to the product. That wouldn't be possible to do visually.

V2-OMG!
26th Jul 2011, 04:57
Oh wow! This is Twilight Zone stuff.....but imagine the possibilities!

Larger scanners that fit a person, and the "powder" is substitued with stem cells.....out comes an exact replica.

I wonder how much they will cost? Maybe they will come out with something you could hook up to your pc.

umm....I'd like a 3-D copy of this please. :E

http://pic80.picturetrail.com/VOL1942/12014112/21796710/397848015.jpg

But...I'll probably be so decrepit and senile by then that I'll have to ask..."I need some help here....is this for real or not?" :(

surely not
26th Jul 2011, 05:12
But if you scan that V2-OMG you will end up with a big head, shoulders, arms and upper body only??

I looked to see if the date 01 April was mentioned anywhere on the clips but it isn't. Flipping amazing what can be reproduced these days and how.

Just imagine how easy it will be for the restorers of aircraft, cars and trains in future to get replicated parts instead of special and hideously expensive forgings having to be made.

Unemployment is certainly going to rise as these get more sophisticated and replace whole factories as needed now.

chuks
26th Jul 2011, 08:52
That is correct, I think, to note that the wrench is non-functional. You would have to disassemble it and scan the body, the axle, the screw and the moving jaw separately and then assemble the parts, but even then you would still have a wrench made of plastic and not of steel. It would be useful if you wanted to see if the wrench fit some space or part but it could not be used in the same way as the original wrench.

When it comes to scanning and duplicating living organisms you run up against the sheer amount of data that is involved. A wrench can be made of just one mixture of compounds, alloy steel, but a living organism is much more complex than that, even a very simple one.

Viruses we can do, I think, but it's arguable what sort of life form they represent.

tony draper
26th Jul 2011, 09:05
I watched kit like this making a exact copy of part of a patients skull that was used by a surgeon doing facial reconstruction so he could figure where he should deploy his hacksaw.
:uhoh:

The SSK
26th Jul 2011, 09:20
V2-OMG! - But...I'll probably be so decrepit and senile by then that I'll have to ask..."I need some help here....is this for real or not?"

Don't worry V2, by then you'll be able to receive an orgasm as an e-mail attachment.
lifeguard.ogm or whatever

Al Fakhem
26th Jul 2011, 14:17
Whilst the parts are not as strong as the final versions (made from steel, aluminium, carbon etc.), the 3-D printing method does let you make a working model of your design and provides an indication of all bits and pieces will work together as planned.

On the other hand, you can use the 3-D model as a positive from which to make a mould, with which you can then cast the final part.

Ancient Observer
26th Jul 2011, 15:31
I think V2is on the right path with this technology.

Where do I place my order for 2 working Gwyneths?? (One for upstairs, one for downstairs)

ChrisVJ
26th Jul 2011, 19:39
Chuks and other non believers.

You do have to see it to believe. I am not sure of the scanning technology but for sure these days a computer would have no problem at all extrapolating the individual parts from a surface scan and YES the tool was a working replica straight from the powder. That is what is so mind blowing.

I understand small versions of this are already available for amateur use, Could be a very interesting few years, I can not tell you how many times I have been stuck replacing a whole section of machinery etc because some little plastic knob or handle broke. As it stands today I need one knob for the stove, $30 because they only sell them in sets, a Knob for an old car heater, collector's cost, a finger pull that activates the on/off switch on a power tool, (four to six weeks from distributor,) all these I could make in an hour with one of these gizmos.

arcniz
27th Jul 2011, 00:45
Whilst the parts are not as strong as the final versions (made from steel, aluminium, carbon etc.), the 3-D printing method does let you make a working model of your design and provides an indication of all bits and pieces will work together as planned.

A technology like this can take a few hundred years to develop.

The progress seen in just a few decades already boggles the mind.

Next phase - already underway, is to integrate machine designs captured through various scanning and imaging methods with engineering models in formulaic or synthesized format, such that the machine controlling the process can fully conceptualize the functional design of the thing being copied, make adjustments for desired variations in functions or size or materials or other specification-related qualities, then generate a full new set of design documentation, and finally produce one or more of the desired device.

Step following that will be to manufacture critical parts of such machines with metals, plastics, and various supermaterials that are created only while being applied to the specific, individual thing being autofactured at moment.
In this context, new materials - metals, plastics, glasses & composites will be caused to exist only as they are laid down, atom by atom or molecule by molecule (or hadron by hadron) -- with properties that will make our current best things seem like last-week's jello.

---- here's a quick history of mechanised mfg quite carelessly and arbitrarily cribbed together from various obvious places on the net (and then edited with an axe to fit the ?new? 30k char limit):

(rough history)

1801, Joseph Marie Jacquard, a silk-weaver, invented an improved textile loom. The Jacquard loom was the first machine to use punched card. These punched cards controlled the weaving, enabling an ordinary workman to produce the most beautiful patterns in a style previously accomplished only with patience, skill, and hard work.

Rotary filing long predated milling. A rotary file by Jacques de Vaucanson, circa 1760, is well known.[3][4] It is clear that milling machines as a distinct class of machine tool (separate from lathes running rotary files) first appeared between 1814 and 1818. The centers of earliest development of true milling machines were two federal armories of the U.S. (Springfield and Harpers Ferry) together with the various private armories and inside contractors that shared turnover of skilled workmen with them.

Between 1912 and 1916, Joseph W. Roe, a respected founding father of machine tool historians, credited Eli Whitney (one of the private arms makers mentioned above) with producing the first true milling machine.[5][6] By 1918, he considered it "Probably the first milling machine ever built—certainly the oldest now in existence […]."[7] However, subsequent scholars, including Robert S. Woodbury[8] and others,[9] have improved upon Roe's early version of the history and suggest that just as much credit—in fact, probably more—belongs to various other inventors, including Robert Johnson of Middletown, Connecticut; Captain John H. Hall of the Harpers Ferry armory; Simeon North of the Staddle Hill factory in Middletown; Roswell Lee of the Springfield armory; and Thomas Blanchard. (Several of the men mentioned above are sometimes described on the internet as "the inventor of the first milling machine" or "the inventor of interchangeable parts". Such claims are oversimplified, as these technologies evolved over time among many people.)

The automation of machine tool control began in the 19th century with cams that "played" a machine tool in the way that cams had long been playing musical boxes or operating elaborate cuckoo clocks. Thomas Blanchard built his gun-stock-copying lathes (1820s–30s), and the work of people such as Christopher Miner Spencer developed the turret lathe into the screw machine (1870s). Cam-based automation had already reached a highly advanced state by World War I (1910s).

However, automation via cams is fundamentally different from numerical control because it cannot be abstractly programmed. Cams can encode information, but getting the information from the abstract level of an engineering drawing into the cam is a manual process that requires sculpting and/or machining and filing.

Various forms of abstractly programmable control had existed during the 19th century: those of the Jacquard loom, player pianos, and mechanical computers pioneered by Charles Babbage and others. These developments had the potential for convergence with the automation of machine tool control starting in that century, but the convergence did not happen until many decades later.
[edit] Tracer control

The application of hydraulics to cam-based automation resulted in tracing machines that used a stylus to trace a template, such as the enormous Pratt & Whitney "Keller Machine", which could copy templates several feet across.[1] Another approach was "record and playback", pioneered at General Motors (GM) in the 1950s, which used a storage system to record the movements of a human machinist, and then play them back on demand. Analogous systems are common even today, notably the "teaching lathe" which gives new machinists a hands-on feel for the process. None of these were numerically programmable, however, and required a master machinist at some point in the process, because the "programming" was physical rather than numerical.
[edit] Servos and selsyns

One barrier to complete automation was the required tolerances of the machining process, which are routinely on the order of thousandths of an inch. Although connecting some sort of control to a storage device like punched cards was easy, ensuring that the controls were moved to the correct position with the required accuracy was another issue. The movement of the tool resulted in varying forces on the controls that would mean a linear input would not result in linear tool motion. The key development in this area was the introduction of the servomechanism, which produced highly accurate measurement information. Attaching two servos together produced a selsyn, where a remote servo's motions were accurately matched by another. Using a variety of mechanical or electrical systems, the output of the selsyns could be read to ensure proper movement had occurred (in other words, forming a closed-loop control system).

Parsons and the invention of NC

The birth of NC is generally credited to John T. Parsons,[3] a machinist and salesman at his father's machining company, Parsons Corp.

In 1942 he was told that helicopters were going to be the "next big thing" by the former head of Ford Trimotor production, Bill Stout. He called Sikorsky Aircraft to inquire about possible work, and soon got a contract to build the wooden stringers in the rotor blades. After setting up production at a disused furniture factory and ramping up production, one of the blades failed and it was traced to the spar. As at least some of the problem appeared to stem from spot welding a metal collar on the stringer to the metal spar, so Parsons suggested a new method of attaching the stringers to the spar using adhesives, never before tried on an aircraft design.[4]

That development led Parsons to consider the possibility of using stamped metal stringers instead of wood, which would be much stronger and easier to make. The stringers for the rotors were built from a design provided by Sikorsky, which was sent to Parsons as a series of 17 points defining the outline. Parsons then had to "fill in" the dots with a french curve to generate an outline they could use as a template to build the jigs for the wooden stringers. Making a metal cutting tool able to cut that particular shape proved to be difficult. Parsons went to Wright Field to see Frank Stulen, the head of the Propeller Lab Rotary Ring Branch. During their conversation, Stulen concluded that Parsons didn't really know what he was talking about. Parsons realized this, and hired Stulen on the spot. Stulen started work on 1 April 1946 and hired three new engineers to join him.[4]

Stulen's brother worked at Curtis Wright Propeller, and mentioned that they were using punched card calculators for engineering calculations. Stulen decided to adopt the idea to run stress calculations on the rotors, the first detailed automated calculations on helicopter rotors.[4] When Parsons saw what Stulen was doing with the punched card machines, he asked Stulen if they could be used to generate an outline with 200 points instead of the 17 they were given, and offset each point by the radius of a mill cutting tool. If you cut at each of those points, it would produce a relatively accurate cutout of the stringer even in hard steel, and it could easily be filed down to a smooth shape. The resulting tool would be useful as a template for stamping metal stringers. Stullen had no problem making such a program, and used it to produce large tables of numbers that would be taken onto the machine floor. Here, one operator read the numbers off the charts to two other operators, one on each of the X- and Y- axes, and they would move the cutting head to that point and make a cut.[4] This was called the "by-the-numbers method".

At that point Parsons conceived of a fully automated tool. With enough points on the outline, no manual working would be needed, but with manual operation, the time saved by having the part more closely match the outline was offset by the time needed to move the controls. If the machine's inputs were attached directly to the card reader, this delay, and any associated manual errors, would be removed and the number of points could be dramatically increased. Such a machine could repeatedly punch out perfectly accurate templates on command. But at the time Parsons had no funds to develop his ideas.

When one of Parsons's salesmen was on a visit to Wright Field, he was told of the problems the newly-formed US Air Force was having with new jet designs. He asked if Parsons had anything to help them. Parsons showed Lockheed their idea of an automated mill, but they were uninterested.
This was not an impossible problem to solve, but would require some sort of feedback system, like a selsyn, to directly measure how far the controls had actually turned. Faced with the daunting task of building such a system, in the spring of 1949 Parsons turned to Gordon S. Brown's Servomechanisms Laboratory at MIT, which was a world leader in mechanical computing and feedback systems.[5] During the war the Lab had built a number of complex motor-driven devices like the motorized gun turret systems for the Boeing B-29 Superfortress and the automatic tracking system for the SCR-584 radar. They were naturally suited to technological transfer into a prototype of Parsons's automated "by-the-numbers" machine.


Instead, in 1950 MIT bought a surplus Cincinnati Milling Machine Company "Hydro-Tel" mill of their own and arranged a new contract directly with the Air Force that froze Parsons out of further development.[4] Parsons would later comment that he "never dreamed that anybody as reputable as MIT would deliberately go ahead and take over my project."[4] In spite of the development being handed to MIT, Parsons filed for a patent on "Motor Controlled Apparatus for Positioning Machine Tool" on 5 May 1952, sparking a filing by MIT for a "Numerical Control Servo-System" on 14 August 1952. Parsons received US Patent 2,820,187 on 14 January 1958, and the company sold an exclusive license to Bendix. IBM, Fujitsu and General Electric all took sub-licenses after having already started development of their own devices.



A neew NC design was publicly demonstrated in September 1952, appearing in that month's Scientific American.[1] MIT's system was an outstanding success by any technical measure, quickly making any complex cut with extremely high accuracy that could not easily be duplicated by hand. However, the system was terribly complex, including 250 vacuum tubes, 175 relays and numerous moving parts, reducing its reliability in a production environment. It was also very expensive, the total bill presented to the Air Force was $360,000.14, $2,641,727.63 in 2005 dollars.[7] Between 1952 and 1956 the system was used to mill a number of one-off designs for various aviation firms, in order to study their potential economic impact.[8]
[edit] Proliferation of NC

The Air Force funding for the project ran out in 1953, but development was picked up by the Giddings and Lewis Machine Tool Co. In 1955 many of the MIT team left to form Concord Controls, a commercial NC company with Giddings' backing, producing the Numericord controller.[8] Numericord was similar to the MIT design, but replaced the punch tape with a magnetic tape reader that General Electric was working on. The tape contained a number of signals of different phases, which directly encoded the angle of the various controls. The tape was played at a constant speed in the controller, which set its half of the selsyn to the encoded angles while the remote side was attached to the machine controls. Designs were still encoded on paper tape, but the tapes were transferred to a reader/writer that converted them into magnetic form. The magtapes could then be used on any of the machines on the floor, where the controllers were greatly reduced in complexity. Developed to produce highly accurate dies for an aircraft skinning press, the Numericord "NC5" went into operation at G&L's plant at Fond du Lac, WI in 1955.[9]

Monarch Machine Tool also developed an numerical controlled lathe, starting in 1952. They demonstrated their machine at the 1955 Chicago Machine Tool Show (predecessor of today's IMTS), along with a number of other vendors with punched card or paper tape machines that were either fully developed or in prototype form. These included Kearney & Trecker’s Milwaukee-Matic II that could change its cutting tool under numerical control,[9] a common feature on modern machines.

A Boeing report noted that "numerical control has proved it can reduce costs, reduce lead times, improve quality, reduce tooling and increase productivity.”[9] In spite of these developments, and glowing reviews from the few users, uptake of NC was relatively slow. As Parsons later noted:

The NC concept was so strange to manufacturers, and so slow to catch on, that the US Army itself finally had to build 120 NC machines and lease them to various manufacturers to begin popularizing its use.[4]

In 1958 MIT published its report on the economics of NC. They concluded that the tools were competitive with human operators, but simply moved the time from the machining to the creation of the tapes. In Forces of Production, Noble[10] claims that this was the whole point as far as the Air Force was concerned; moving the process off of the highly unionized factory floor and into the un-unionized white collar design office. The cultural context of the early 1950s, a second Red Scare with a widespread fear of a bomber gap and of domestic subversion, sheds light on this interpretation. It was strongly feared that the West would lose the defense production race to the Communists, and that syndicalist power was a path toward losing, either by "getting too soft" (less output, greater unit expense) or even by Communist sympathy and subversion within unions (arising from their common theme of empowering the working class).
[edit] CNC arrives

Many of the commands for the experimental parts were programmed "by hand" to produce the punch tapes that were used as input. During the development of Whirlwind, MIT's real-time computer, John Runyon coded a number of subroutines to produce these tapes under computer control. Users could enter a list of points and speeds, and the program would generate the punch tape. In one instance, this process reduced the time required to produce the instruction list and mill the part from 8 hours to 15 minutes. This led to a proposal to the Air Force to produce a generalized "programming" language for numerical control, which was accepted in June 1956.[8]

Starting in September, Ross and Pople outlined a language for machine control that was based on points and lines, developing this over several years into the APT programming language. In 1957 the Aircraft Industries Association (AIA) and Air Material Command at Wright-Patterson Air Force Base joined with MIT to standardize this work and produce a fully computer-controlled NC system. On 25 February 1959 the combined team held a press conference showing the results, including a 3D machined aluminum ash tray that was handed out in the press kit.[8]

Meanwhile, Patrick Hanratty was making similar developments at GE as part of their partnership with G&L on the Numericord. His language, PRONTO, beat APT into commercial use when it was released in 1958.[11] Hanratty then went on to develop MICR magnetic ink characters that were used in cheque processing, before moving to General Motors to work on the groundbreaking DAC-1 CAD system.

APT was soon extended to include "real" curves in 2D-APT-II. With its release, MIT reduced its focus on CNC as it moved into CAD experiments. APT development was picked up with the AIA in San Diego, and in 1962, by Illinois Institute of Technology Research. Work on making APT an international standard started in 1963 under USASI X3.4.7, but many manufacturers of CNC machines had their own one-off additions (like PRONTO), so standardization was not completed until 1968, when there were 25 optional add-ins to the basic system.[8]

Just as APT was being released in the early 1960s, a second generation of lower-cost transistorized computers was hitting the market that were able to process much larger volumes of information in production settings. This reduced the cost of implementing a NC system and by the mid 1960s, APT runs accounted for a third of all computer time at large aviation firms.
[edit] CAD meets CNC

While the Servomechanisms Lab was in the process of developing their first mill, in 1953, MIT's Mechanical Engineering Department dropped the requirement that undergraduates take courses in drawing. The instructors formerly teaching these programs were merged into the Design Division, where an informal discussion of computerized design started. Meanwhile the Electronic Systems Laboratory, the newly rechristened Servomechanisms Laboratory, had been discussing whether or not design would ever start with paper diagrams in the future.[12]

In January 1959, an informal meeting was held involving individuals from both the Electronic Systems Laboratory and the Mechanical Engineering Department's Design Division. Formal meetings followed in April and May, which resulted in the "Computer-Aided Design Project". In December 1959, the Air Force issued a one year contract to ESL for $223,000 to fund the project, including $20,800 earmarked for 104 hours of computer time at $200 per hour.[13] This proved to be far too little for the ambitious program they had in mind, although their engineering calculation system, AED, was released in March 1965.

In 1959, General Motors started an experimental project to digitize, store and print the many design sketches being generated in the various GM design departments. When the basic concept demonstrated that it could work, they started the DAC-1 project with IBM to develop a production version. One part of the DAC project was the direct conversion of paper diagrams into 3D models, which were then converted into APT commands and cut on milling machines. In November 1963 a trunk lid design moved from 2D paper sketch to 3D clay prototype for the first time.[14] With the exception of the initial sketch, the design-to-production loop had been closed.

Meanwhile, MIT's offsite Lincoln Labs was building computers to test new transistorized designs. The ultimate goal was essentially a transistorized Whirlwind known as TX-2, but in order to test various circuit designs a smaller version known as TX-0 was built first. When construction of TX-2 started, time in TX-0 freed up and this led to a number of experiments involving interactive input and use of the machine's CRT display for graphics. Further development of these concepts led to Ivan Sutherland's groundbreaking Sketchpad program on the TX-2.

Sutherland moved to the University of Utah after his Sketchpad work, but it inspired other MIT graduates to attempt the first true CAD system. It was Electronic Drafting Machine (EDM), sold to Control Data and known as "Digigraphics", that Lockheed used to build production parts for the C-5 Galaxy, the first example of an end-to-end CAD/CNC production system.

By 1970 there were a wide variety of CAD firms including Intergraph, Applicon, Computervision, Auto-trol Technology, UGS Corp. and others, as well as large vendors like CDC and IBM.
[edit] Proliferation of CNC

The price of computer cycles fell drastically during the 1960s with the widespread introduction of useful minicomputers. Eventually it became less expensive to handle the motor control and feedback with a computer program than it was with dedicated servo systems. Small computers were dedicated to a single mill, placing the entire process in a small box. PDP-8's and Data General Nova computers were common in these roles. The introduction of the microprocessor in the 1970s further reduced the cost of implementation, and today almost all CNC machines use some form of microprocessor to handle all operations.

The introduction of lower-cost CNC machines radically changed the manufacturing industry. Curves are as easy to cut as straight lines, complex 3-D structures are relatively easy to produce, and the number of machining steps that required human action have been dramatically reduced. With the increased automation of manufacturing processes with CNC machining, considerable improvements in consistency and quality have been achieved with no strain on the operator. CNC automation reduced the frequency of errors and provided CNC operators with time to perform additional tasks. CNC automation also allows for more flexibility in the way parts are held in the manufacturing process and the time required to change the machine to produce different components.

During the early 1970s the Western economies were mired in slow economic growth and rising employment costs, and NC machines started to become more attractive. The major U.S. vendors were slow to respond to the demand for machines suitable for lower-cost NC systems, and into this void stepped the Germans. In 1979, sales of German machines surpassed the U.S. designs for the first time. This cycle quickly repeated itself, and by 1980 Japan had taken a leadership position, U.S. sales dropping all the time. Once sitting in the #1 position in terms of sales on a top-ten chart consisting entirely of U.S. companies in 1971, by 1987 Cincinnati Milacron was in 8th place on a chart heavily dominated by Japanese firms.[15]

Many researchers have commented that the U.S. focus on high-end applications left them in an uncompetitive situation when the economic downturn in the early 1970s led to greatly increased demand for low-cost NC systems. Unlike the U.S. companies, who had focused on the highly profitable aerospace market, German and Japanese manufacturers targeted lower-profit segments from the start and were able to enter the low-cost markets much more easily.[15][16]

As computing and networking evolved, so did direct numerical control (DNC). Its long-term coexistence with less networked variants of NC and CNC is explained by the fact that individual firms tend to stick with whatever is profitable, and their time and money for trying out alternatives is limited. This explains why machine tool models and tape storage media persist in grandfathered fashion even as the state of the art advances.
[edit] DIY, hobby, and personal CNC

EMC is a public domain program operating under the Linux operating system and working on PC based hardware. After the NIST project ended, development continued, leading to EMC2 which is licensed under the GNU General Public License and Lesser GNU General Public License (GPL and LGPL). Derivations of the original EMC software have also led to several proprietary PC based programs notably TurboCNC, and Mach3, as well as embedded systems based on proprietary hardware. The availability of these PC based control programs has led to the development of DIY CNC, allowing hobbyists to build their own [17][18] using open source hardware designs. The same basic architecture has allowed manufacturers, such as Sherline and Taig, to produce turnkey lightweight desktop milling machines for hobbyists.

Eventually, the homebrew architecture was fully commercialized and used to create larger machinery suitable for commercial and industrial applications. This class of equipment has been referred to as Personal CNC. Parallel to the evolution of personal computers, Personal CNC has its roots in EMC and PC based control, but has evolved to the point where it can replace larger conventional equipment in many instances. As with the Personal Computer, Personal CNC is characterized by equipment whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end user, often without professional training in CNC technology.
[edit] Today

Although modern data storage techniques have moved on from punch tape in almost every other role, tapes are still relatively common in CNC systems. Several reasons explain this. One is easy backward compatibility of existing programs. Companies were spared the trouble of re-writing existing tapes into a new format. Another is the principle, mentioned earlier, that individual firms tend to stick with whatever is profitable, and their time and money for trying out alternatives is limited. A small firm that has found a profitable niche may keep older equipment in service for years because "if it ain't broke [profitability-wise], don't fix it." Competition places natural limits on that approach, as some amount of innovation and continuous improvement eventually becomes necessary, lest competitors be the ones who find the way to the "better mousetrap".

The proliferation of CNC led to the need for new CNC standards that were not encumbered by licensing or particular design concepts, like APT. A number of different "standards" proliferated for a time, often based around vector graphics markup languages supported by plotters. One such standard has since become very common, the "G-code" that was originally used on Gerber Scientific plotters and then adapted for CNC use. The file format became so widely used that it has been embodied in an EIA standard. In turn, while G-code is the predominant language used by CNC machines today, there is a push to supplant it with STEP-NC, a system that was deliberately designed for CNC, rather than grown from an existing plotter standard.[citation needed]

While G-code is the most common method of programming, some machine-tool/control manufacturers also have invented their own proprietary "conversational" methods of programming, trying to make it easier to program simple parts and make set-up and modifications at the machine easier (such as Mazak's Mazatrol and Hurco). These have met with varying success.[citation needed]

A more recent advancement in CNC interpreters is support of logical commands, known as parametric programming (also known as macro programming). Parametric programs include both device commands as well as a control language similar to BASIC. The programmer can make if/then/else statements, loops, subprogram calls, perform various arithmetic, and manipulate variables to create a large degree of freedom within one program. An entire product line of different sizes can be programmed using logic and simple math to create and scale an entire range of parts, or create a stock part that can be scaled to any size a customer demands.

OFSO
27th Jul 2011, 12:47
I need one knob for the stove, $30 because they only sell them in sets,

Smeg cookers are particularly bad at knobs falling off. I go back to the store where I bought ours and swap my defective knob for a shiny new one off their demo model. There are very few shiny new knobs left on thir demo model - time they ordered a new one !