HOI presentation barry hansen magnetic launches
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HOI presentation barry hansen magnetic launches



Barry Hansen, as part of our Hands-On Ideas series, describes how he was inspired to build his own magnetic launch devices. Going from his science fiction influences through the theory and project ...

Barry Hansen, as part of our Hands-On Ideas series, describes how he was inspired to build his own magnetic launch devices. Going from his science fiction influences through the theory and project iterations, he shows how a maker can explore space transportation technology.



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HOI presentation barry hansen magnetic launches HOI presentation barry hansen magnetic launches Presentation Transcript

  • Magnetic LaunchesBarry HansenHands-On Ideas 10May 15th, 2013
  • “He who controls magnetism, controls the universe”Diet Smith, as quoted in Dick Tracy comic strip, circa 1945"Well, if you cant believe what you read in a comic book, what can you believe?!“Bullwinkle J. Moose [Jay Ward]The Space Coupe is basedon stories from the DickTracy newspaper comicstrip. It was invented byDiet Smith, Tracys friend,industrialist and brilliantinventor. The Coupe reliedon the planetary magneticfield. His Magnetic Air Carwas also a main feature ofthe series.
  • About BarrySeattle, Washington, USAMarried, 3 kids, software programmer
  • What inspired this work?In 1937, Northrup published a feasibility study of amagnetic launch to moon, in his book “Zero to Eighty”
  • Getting Started•  1997 website “How to Colonizean Asteroid” with a 3-stage “NailShooter”•  Kids and science fairs•  Learning HTML•  Website generated lots ofquestions and ideas•  Simple magnetic rail car led to alauncher, then a better launcher,and more experimentsRelevant image here
  • Why Coilguns? All Electric•  Mechanical toleranceLoose fit, no wear•  Shape toleranceLaunch any iron that fits in barrel•  Speed controlJust twist a knob to choose speed•  Speed repeatabilityAdd coil to fine-tune speedof an existing gun•  Simple
  • Why Coilguns? No explosion• Hyper-velocity: Just keep adding coils• Inert: No combustible gas expelled• Quiet: No extra noise• Storage safety: No combustible propellant
  • What Barry Likes to Explore•  What is needed for a single stage to work well?•  Why are magnetic launchers so very inefficient?Openly Disruptive
  • Magnetic LaunchersIncremental Refinement
  • Project: Mark 1•  A mashup of coils, timers, drill parts.•  Principle: Three coils, fired in overlapping sequence.•  Result: Poor. Fixed timing led to wildly variable results.Large inductance in coil slows down timing.
  • Project: Mark 2•  What size coil works best?•  Principle: One coil with taps between layers.•  Result: A small number of layers is best.
  • Project: Mark 3•  Portable low-power single-stage in a plastic toolbox•  Principle: One coil with iron to improve flux path•  Result: High efficiency (6%)
  • Project: Mark 4•  Single stage, more energy, launch small nails•  Principle: Critical damping to prevent negative voltage•  Result: Poor efficiency (0.1%).One stage does not scale up well to more energy.
  • Project: Mark 5•  Single stage, copper switch, heavy projectile•  Principle:- Copper wedge to close circuit•  Result: Work in progress
  • Project: Mark 6•  Five stage, optical sensors, puck switch, heavy projectiles•  Principle: Efficiency via low energy stages, lots of stages•  Result: Future work
  • Discovery Channel Launcher•  Episode of “Engineering the Future” series•  Prof. Roger Angel at the Univ. of Arizona proposedtrillions of lenses in space to reduce global warming•  Principle: Flat pancake coil repels aluminum plateImage here
  • Post-ProjectWhat’s Next
  • How you can build off this work:Experiments•  Magnetic flux path•  Switching device:ContactsMosfetsIGBTs•  More stages
  • How you can build off this work:Tools•  Optical detectors•  Arduino controllers•  Speed measurement
  • Further reading•  www.coilgun.info – Barry Hansen•  www.coilgun.com – James Paul•  http://4hv.org – High Voltage Forums•  www.amazon.com/gp/product/0071755675Ch.1 from “15 Dangerously Mad Projects forthe Evil Genius” by Simon Monk•  www.femm.info – Finite Element MethodMagnetics, by Dr. David Meeker
  • Question and Answers
  • Top Questions•  Where can I find capacitors?•  Does high voltage work better than low voltage?•  What about launching a powerful magnet instead of iron?