Talk:Numerical control

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I don't understand this sentence: "His concept was to machine to setpoints as guides for subsequent manual finishing, that is, to speed up a manual process so more points could be included." I find the author's statement ambiguous, and I hesitate to try to clarify it because I cannot get the sense of what is meant.

I believe the original author was explaining the crude steps taken 60 years ago to create an elliptical or curved shape on flat material by intersecting short lines through a dot to dot pattern representing the desired shape. The more points used, the smoother the curve would become. Today's modern equipment still only cut straight lines. They simply cut a large amount of very small lines that make up a circle. 12/13/06 AD

Can some1 guide me with respect to hw programming language C is used to automate these machines. i hear one can use turbo C to write assembly level programs and then connect it to automate the machine.Where on web can i get further details about this. 12/1/07 AD

This is false. Modern machine tools have complex, multiprocessor controllers. G-Code, as an interpreted language, fills all the needs a machine tool is capable of without the need for a higher level language. A couple open source CNC projects expose the axis controls directly, but you will not find this on production equipment. - Toastydeath 15:03, 12 January 2007 (UTC)

[edit] POV question

This passage strikes me as particularly biased in its wording. It may be a summary of the thesis of David Noble's book "Forces of Production."

Overall I'd like more citations on this page.

Record/playback is different from numerical control in that the program is produced by the machinist in the process of making the first part. The Air Force wanted numerical control and not record/playback because 1) the latter put the machinists who were union members in charge of program production, thus union strikes could result in unacceptable delays in military production, and 2) numerical control demonstrated the capability of producing complex parts that were not possible by the conventional manual methods used in the record/playback technique. The Air Force used its deep pockets to get its way and while American manufacturing may have been better served by the simpler Parsons concept or by record/playback, today this is a moot issue.

159.53.46.141 20:43, 3 July 2007 (UTC)

Yes, this is not only biased, but flat out wrong. Record/playback was only "viable," if you want to call it that, in the absolute infancy of NC controls. Tracer systems are more practical and useful (even today), and those predate record/playback. It's a factually baseless passage meant to curry favorable public opinion in an old argument that is no longer occurring over CNC and the future of manufacturing in America. - Toastydeath 00:15, 8 November 2007 (UTC)

I am not sure that I am the one who actually did the entry for Numerical Control, but the text is certainly mine from other materials I have written. I don't see the bias. Also, with regard to the statement that record/playback was only viable in the infancy of NC controls, Mr. Nobel's book explains that record/playback was one of many alternative technologies that never got out of the lab because the U.S. Air Force used its deep pockets to promote by-the-numbers. Record/playback was not a NC concept; it was a different concept. Today we have so-called "teach lathes" that are a variant of record/playback that is achieved with CNC. Siemens, who I work for, has an HMI called ManualTurn. The operator uses handwheels and dialog boxes to make the first part. This process produces the program that can be run to make the 2nd, 3rd, and subsequent copies. If we want a historical precedent for this, record/playback as it was developed by GE in one of their labs, seems to be as good as anything. —Preceding unsigned comment added by 208.5.44.21 (talk) 15:16, 8 November 2007 (UTC)

Record/playback DID get out of the lab, and it did get into production. Whereupon it was found to be a huge waste of money and time for the businesses attempting to use it. You can still pick up old R/P machines, but most have been converted to numeric control. The problem is simple - record/playback is akin to using training wheels on a bike. The union aspect is very much overemphasized in the current wording of the article, as NC/CNC is a technically and practically superior control methodology. Even "Teach" lathes do not rely on the record/playback principle. They rely on conversational programming on top of a CNC, which has nothing to do with record/playback. Older Dixi horizontal boring mills can be had with 'true' record/playback, and it is nowhere near as useful or fast as the conversational CNC variant. Record/playback was never viable on technical or practical merits, and it has been given a chance. It just failed miserably. - Toastydeath 22:26, 8 November 2007 (UTC)

I just changed that sentence and then came here and saw this discussion. ("may have been better served" etc.) Maybe I misunderstood the original author's exact point about record/playback, but I have to ask, perplexed: How could anyone ever use record/playback to do the wicked 3D diesinking that AutoCAD and Mastercam software team up to do nowadays??? And even if it was humanly possible, and a few amazing people could do it, how would that have anything to do with practical use in the tool and die shop down the street? That doesn't make sense to me. — ¾-10 02:00, 6 February 2008 (UTC)

Noble 1986 (Forces of Production) looks like an interesting book, regardless. Maybe I should read that before editing more here. — ¾-10 03:49, 6 February 2008 (UTC)

[edit] What is numerical filing

72.27.54.23 (talk) 17:59, 8 April 2008 (UTC)can you please tell me what it is