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Maglev Chip Finds Niche in Power Tools 87

andhar writes: "This story in the Financial Times just goes to show you that it's often not the sexiest application of a technology that makes the best business sense. 'Today, while "maglev" trains remain a technological curiosity, linear motors are being quietly exploited in the less obviously glamorous field of machine tools. One of the leaders in such applications is Forest-Liné, a French company that makes products vital to the competitiveness of much larger industrial businesses' My margaritas want a maglev blender!"
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Maglev Chip Finds Niche in Power Tools

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  • by Anonymous Coward on Tuesday July 16, 2002 @05:51AM (#3892578)
    Small, quiet, discreet, and energy-efficient. Who says chicks can't get into technology?
  • by e7 ( 117450 ) <webmaster@@@spazquest...org> on Tuesday July 16, 2002 @05:58AM (#3892587) Homepage Journal

    Rock-solid slides for milling machines would rock the world. No, it ain't a sexy application, but it brings us a step closer to the ideal manufacturing scenario, where mechanical parts can actually be CNC-milled before they're even designed.

    • It sounds like your application is time travel, which seems pretty sexy to me.
    • So, uh, how exactly do you machine a part that hasn't been designed yet?

    • Rock-solid slides for milling machines would rock
      the world.

      Widespread deployment of hexapod milling machines would rock the world: no slides at all.
    • Rock-solid slides for milling machines would rock the world.

      Quality milling machine slides are already rock-solid. The gain from linear motors is speed. As the article mentions, this can benefit very large milling operations like milling a long slot in an aircraft wing. In most milling operations, torque is more important than speed, because you've got to keep the work stationary against the cutting forces.

      If you really want speed in a CNC machine, just gear the servos or steppers up instead of down. It'll work great as long as you keep your cuts light.

      No, it ain't a sexy application,

      CNC is always sexy!

      but it brings us a step closer to the ideal manufacturing scenario, where mechanical parts can actually be CNC-milled before they're even designed.

      I doubt these linear motors run fast enough to travel in time.

      • CNC is sexy? you must be a little kid, CNC can be operated by any chimpanzee with a few minuites of instruction. I have been a machinist for 15 years and every time I hear how wonderful a CNC mill is I wanna puke. The primary purpose of computerized machine tools is to reduce the cost of labor in manufacturing. CNC requires NO SKILL. It means a 6 year old can safely operate it. And of course, be paid accordingly. If ya can't make it without computers, yer gonna be in trouble when you can't find a decent programmer because the industry has eliminated manual machining, and nobody really knows what they're doing. And incidentally, the speeds and feedrates are dictated by the materials being cut, not the available machine tools. If you try to treat titanium like aluminium, yer gonna smoke cutters no matter what kind of machine you have.
    • > mechanical parts can actually be CNC-milled before they're even designed.

      I've seen that done. It's called fucking up.
    • They're not "new," we used Anorad [anorad.com] linear motors back in college too many years ago to remember, back mapping the EMF using a sub-nanometer resolution laser interferometer to improve the velocity and position accuracy (they've been around since the '50s).

      Currently I help design machines that use a mixture of linear motors and ball screws as appropriate. In applications with high linear speed, short/medium stroke, and no static hold requirement, linear motors are a good choice.

      If you move slowly, that long chain of rare earth magnets isn't a good investment compared to a ball screw (but the ones that came out of a linear motor we broke that are on my refrigerator really impress people.)

      If you need a long stroke, that chain of magnets gets very expensive ( though they're used for elevators sometimes. [fujitec.co.jp]) On the other hand, ball screws can be limiting in applications requiring long length as the driven mass increases linearly with the length of the drive, not the case with a linear motor.

      If your application requires extended static holds, then a ball screw is a lot easier to integrate.

      For most machine tool applications they aren't really a good choice (since machine tools typically have feed rates and target accelerations well suited to ball screws) but a number of companies do build machines with linear motors [google.com] for one or more axis, and they tend to dominante the "ultra-high speed machining market."

      This [moldmakermag.com] is a decent comparison of the strengths and weaknesses of the two dominant linear motion technologies for the curious.

      Now if you want a really new technology for linear motion appropriate to high accuracy machining, then what you really want is hydrostatic leadscrews and bearings. [machineshopguide.com]
    • No, the ideal manufacturing scenario is casting everything with no machining (extra step, waste products, expensive equipment requiring skilled operators, and periodic replacement bits, which are also very expensive).

      If everything could just be cast - perfectly, then, well metal things would be as cheap as plastic.
    • I just wanna know who marked me Informative ... were they going by 'buzzwords,' or what ... ?
  • by Belly ( 153998 ) on Tuesday July 16, 2002 @06:07AM (#3892609)
    This is news? My electric toothbrush has a linear motor..

    http://www.panasonic.com/consumer_electronics/pe rs onal_care/oral_care.asp#technobrush
  • http://www.proscitech.com/get_frames.htm?e11a.htm

    OK, more 'mag' than actual 'lev', but still...
  • curiosity? (Score:3, Interesting)

    by MiTEG ( 234467 ) on Tuesday July 16, 2002 @06:52AM (#3892689) Homepage Journal
    "maglev" trains remain a technological curiosity?
    I disagree. In China (actually Germany I think), one is being built now. Maybe still a curiousity, but only as much as anything else that is part of an evolving technology.

    In my mind, the best application, and perhaps the most glamorous, is in energy storage using electromagnetic flywheels. A few years back, Scientific American published an article about electromagnetic flywheels being used as backup generators; get them spinning once and bury them underground, with almost no friction then spin for a LONG time. Power goes off, all you have to do is turn on the generator and you've got power to the length of time relative to the mass of the flywheel. For a while that was part of the big hype about hydrogen powered fuel cells in cars, though the 100,000RPM flywheel seems to seems to have scared away a lot of people.

    • Re:curiosity? (Score:2, Interesting)

      by altgrr ( 593057 )
      There was a Maglev railway set up way back in 1984 to take passengers from Birmingham International station to the airport it served, and it worked, albeit briefly. However, it was closed in 1995 and a new, but far less exciting, railway link is being set up.

      This site [google.co.uk] (cache of a BBC page) gives a few details on the old Maglev system that was in use - it doesn't look as impressive as the 350mph+ trains being trialled in Japan though.
    • 100,000RPM flywheel
      There are lots more benefits to no friction, this technology could be used in hard disks to suspend the platters in mid-air, this would also eliminate run-out problems that ball bearings in raceways have. It might even be better than the new fluid bearings. 100,000 RPM in a hard disk sounds mighty cool to me.
      • I'm not sure i would want electromagnetic flywheels in my HD...
      • Even if you could spin the hard disk at 100,000 rpm axle and friction wise, you would have a hell of a time keeping the platters from exploding.

        Hell, even at 10,000 rpm, I wouldn't want to see what a platter physical failure would look like, that's a lot of energy in one spot.

        Platters are pretty strong these days at least. I've taken apart old and modern hard disks, and the modern platters are a hell of a lot stronger than the old ones. It seems the older ones were made of some brittle glass/ceramic, and the newer ones are some metal alloy. The old ones also probably never went higher than 3600 rpm, if that.
        • Jet engines have an RPM of 30,000 or higher, plus they get birds sucked in there. I don't think platter manufacturers have really tested the limits, such as by using jet engine materials [ed.ac.uk]

          These energy levels are used everyday, face it, it's easy to die - ever seen a biker's piston fly out of his engine at 7500rpm? I'm telling you bikes should have auto gearboxes, many still have manual and this piston will give you more than just a sore ass. Jet engines despite having to be light to minimise fuel consumption can still lose turbine blades after sucking in birds without throwing the blade out of it's casing and through the cabin, slicing the plane in half. Face it, it's just another way to die, but still with the right mediahype I think we'll see aluminium cases becoming illegal in California.

          • You know, california should just simplify their laws and say what IS legal. It would be a short list.
            • You know, california should just simplify their laws and say what IS legal. It would be a short list.
              Oh man, dude, your comment's a felony in California, if I were you I'd gun it across the State line pronto ;-) actually California jails are supposed to be the nicest in the US, there are advantages to putting the majority of your population in prison you know.
    • Flywheels seem like a great way to store energy, unless you want to use them to store energy in a moving vehicle. Just do NOT turn.

      • Flywheels seem like a great way to store energy, unless you want to use them to store energy in a moving vehicle. Just do NOT turn.

        Run them vertical and don't go up/down any hills you'll be fine, better yet you can negligibly charge it by spinning the car. :-)
      • They're fine, as long as you use them in opposing pairs.
    • The energy storage density in flywheel systems isn't very high unless A) the wheel is very heavy or B) the wheel spins very fast.

      The problem with (A) is that heavy usually means big. The problems with (B) are that it has to be very, very well balanced and fast spinning wheels tend to rip themselves apart unless they are made very strong, so the top speed of the wheel is limited.

      Current flywheel technology really doesn't provide enough storage density for anything other than a backup UPS system, delivering power only to critical systems for a short duration of time.

      Its a nice clean energy storage system, but it still has a ways to go in terms of energy density.
  • a Blender is Rotary. You do not want a linear motor. Dumbass.
  • Here [nctransportation.com] is a cool page on how it works along with some good examples of how maglev trains are NOT simply technological curiosity.

  • linear motors and maglevs are not the same. The latter use the former, that's it. But you can't expect the FT to know this...

    • This is a good point. Obviously overlooked by the posts so far. Linear motors have been around for quite a while, with a drastic slowing in the true integration of the design. However maglevs are a much more affordable way to generate similar results.

      The opportunities, especially in the transportation and space applications are great. Too bad this generally gets such limited exposure. Soon unfortuanately it will go the way of the Wankle Rotary engine and the supercollider. Thanks to all the fossil fuel lobby's.
  • Most people will do something if it makes them money. i guess there's more money in power tools then trains.....hmm..amtrak comes to mind right now..
  • Yawn (again) (Score:2, Informative)

    by Pig Hogger ( 10379 )
    Nothing new there. Is Slashdot a nostalgia technology site????

    More than 20 years ago, I remember seeing at a computer show a daisywheel printer whose head was propelled by a linear motor (it was manufactured by a subsidiary of Exxon).

    And in 1984, in Toronto, the Scarborough RT (Rapid Transit) line [metropla.net] opened, which was the first full scale ICTS implementation [inter.net]. Since then, the small linear motor subway has found home in Vancouver [inter.net] and Detroit [presby.edu].

    • What's new is linear motors with a thrust-to-mass ratio high enough to make them attractive replacements for screw drives in milling tools. That, coupled with sensors and control systems good enough and cheap enough to support the necessary closed-loop operation.

      This is, indeed, significant news for geeks. You're just not the right type of geek to apppreciate it.

  • Today, while "maglev" trains remain a
    technological curiosity, linear motors are being
    quietly exploited in the less obviously
    glamorous field of machine tools.

    I consider machine tools that actually make things much more interesting then commuter trains hauling carloads of suits back and forth between their offices and their McMansions.

    And 'MagLev' is not a synonym for 'linear motor'.
    • Testify!

      Anyone who thinks machining technology isn't sexy has probably never visited a machining plant and seen steel bars being lathed and rolled into transmission gearshafts for motorcycles.

      Flying commuter trains are nice and all (I'm all for efficient public transportation), but really, they just hover a few inches, and the novelty of them will wear off soon enough. Good machine tools, however, increase manufacturing output, and allow all kinds of new products to become available on the cheap.

      In fact, machining is probably the single most important part of our industrial complex. Without machine tools, we'd have almost none of the technology we have today.

      Machining: The gift that keeps on giving!
  • by des09 ( 263929 )
    I may have missed it, but where does it mention chips? are there linear motors on a chip? Has forest designed a control chip?
  • by redtoade ( 51167 ) on Tuesday July 16, 2002 @10:37AM (#3894045) Homepage Journal

    "My margaritas want a maglev blender!"

    There's a difference between levitation and propulsion.

    From the Financial Times article: "Linear motors are "flattened out" versions of conventional rotary motors. As their name implies, they promote linear motion - of the kind required in many kinds of machine tools that use a large number of sliding and shuttling actions, fundamental to the job of cutting metal."

    Linear motors are just rotary motors cut and laid out flat... or another way to explain them is a rotary motor of infinite radius.

    "Maglev" is obviously short for magnetic levitation. Linear motors are common in maglevs simply because there is an air gap between the vehicle and the track. It would be very difficult to use conventional motors in such a system whithout driving wheels (or mechanical friction). However, other types of propulsion can also be used... such as jet engines, solid rocket boosters, etc. Although perhaps not practical for commercial trains, a maglev with rocket propulsion could be used for launching scram jets from the ground.

    Linear motors can be used without magnetic levitation. It is completely feasible to use a linear motor on conventional wheeled "people movers." Although this application is rare since linear motors typical consume more energy than rotary motors.

    • Thanks for your clear informative explanation. I would add one point though. Most people when they hear the term MagLev infer that what is being talked about involves superconducting magnets. Unless there has been a dramatic revolution in room temperature superconductors that I haven't heard about, I don't think we will be seeing those kinds of MagLev devices being put into household appliances in the near future. If you need a super-cold refrigerator to store a ready source of liquid Nitrogen, it would be a very efficient method of powering a household fan to keep you cool on a hot day.

    • High end turbo molecular pumps are often magnetically levitated in order to reduce friction and vibration. The cost of these pumps is higher but they have better vibration characteristics. The downside is that they are more suceptible to damage from shock. If you bang a maglev pump around too much the spindle can touch down and then something very bad is likely to happen due to the large amount of stored energy in the rotor.

      I'm not sure how the maglev systems work in these pumps, I believe that there are sensors and coils that control the position of the spindle.
    • It is completely feasible to use a linear motor on conventional wheeled "people movers."
      Have a listen [rapidtransit.bc.ca] to Vancouver's "people mover" (shockwave site includes audio of train leaving station) - elevated, driverless 2, 4 or 6-car trains that run at about 80km/h.

      The site says: SkyTrain's linear induction motors have no moving parts and rarely require maintenance, making the system one of the most reliable in the world. Whatever. When the new line is done, it will run near my house and take me to work quickly & quietly.
      Although this application is rare since linear motors typical consume more energy than rotary motors.
      We've got lots of hydroelectric power up here, we'd rather run our little trains with it than send it south for lighting up the desert [vegas.com].

  • Maglev trains may use linear motors, but that doesn't make linear motors maglev. There's nothing even high tech about linear motors.
  • Brother Typewriter had a product in the mid 80's called the Brother EM-1 electronic typewriter. The print carraige rolled back and fourth on a Linear Moter.

    It had the advantage of having no belts or pulleys. Nothing to tighten or replace. It couldn't get out of alignment.

    They abandoned it in later models for a wire pulley system. I guess the fact that it sounded like a BART train freaked people out.

  • I (I'm a EE) work with a bunch of Industrial Desingers and they get bored when their project isn't sexy. boo-hoo.

    They should be happy that they are being paid so well and they are employed, so says me.

    If you want something exciting, pick up work on the side. or just surf for porn.
  • Linear motors have been around for quite a while in non "levitation" applications to:

    BTW, why did the FT put a picture of a CCD imager chip on an article about linear motors?

  • I know for a fact that United Parcel Service, has been using a maglev system in their Pacific, WA Hub for almost two years now. There is also plans to build one in Montana even bigger. What does the maglev system do for UPS you ask? It automaticly sorts the packages using all those bar codes and dots they put on the labels.
  • Have been doing this for years.

I just asked myself... what would John DeLorean do? -- Raoul Duke