Page 16 - Wire Rope News & Sling Technology - February 2019
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continued from page 14
         liquid, and solid). But plasma does
         not occur naturally on earth. It takes
         an electrical current or a strong mag-
         netic field in a vacuum to strip or add
         electrons from an inert gas to place the
         molecules in the ionized state, charged
         particular = plasma. When these forces
         are removed the “freed” electrons emit
         light, returning,  and the molecule  re-
         claims  its  stable state.  Plasma is  fa-
         miliar to us, as in neon light tubes, the
         Northern Lights in the sky, plasma tv,
         or the “free” nitrogen released during a
         lightning strike.
           When  welding  with  a plasma arc
         (which is like a little rocket engine), the
         chamber inside the torch forms a vacu-
         um, heating the inert plasma gas that
         expands. The hot plasma ions cause the
         gas to rush out the nozzle and can be
         precisely aimed. Because all this takes
         place inside the nozzle, there is no need
         for a sealed chamber to remove the oxy-
         gen to produce the plasma state of the
         inert gas. In some processes, a shield is
         placed over the area for protection.
           Still,  there  are  complications  for
         some materials. The fusion  zone and
         surface are subject to oxidation  with
         some alloys and demand additional in-
         ert gas protection. Portal seals need to
         be placed over the work area and filled
         with  inert  gas for  protection  against
         contamination.  And there  remain
         some other  drawbacks with  all these
         3D  manufacturing  processes.  First,
         some cannot compete cost-wise  with
         mass produced items on the produc-
         tion line - yet! Also, the smooth finishes
         necessary  for some products are not
         achieved. Likewise,  the variations in
         material types necessary are not avail-  3D Printer built with parts made from a 3D printer! Photo © Josef Kubes | iStockphoto
         able. Inventors are working on it, and
         processes are sprouting.           3D manufacture metal parts. If widely   formed, 3D printed house. The project
           Today’s  hooks are reliable and are   adopted, it could change the way we   using  Branch’s  C-FAB printing  tech-
         cost-effective. I think  we should stay   mass-produce many products. Liver-  nology with carbon fiber polymer.
         with these proven manufacturing    more National Laboratory announced   GE, which  has long been a user  of
         methods. WAAM hooks have an ad-    they  have a  3D  printing  method for   3D metal additive manufacturing, has
         vantage that I see  – time.  It’s said a   stainless-steel parts twice as strong as   a test version of its new metal printer
         hook can be made and delivered in two   traditionally made ones.      fast enough  to make  large  parts and
         weeks compared with a two-month de-  Markforged, a small startup outside   planned to start selling them in 2018!
         livery in the cast/machine method. If a   Boston,  released  the  first  3D  metal   Even outer space is an option. NASA
         hook is holding up a million-dollar-a-  printer for under $100,000. Desktop   has offered monetary incentives to com-
         day job, well, it’s a no brainer - right?  Metal, also in Boston, began to ship   panies able to adapt the 3D additive
                                            its  first  metal  prototyping  machines   manufacturing technique to robots who
         Is the sky the limit?              in  December  2017,  which  they  claim   could build habitat designs on Mars.
           The Caterpillar Tractor Corp. is cur-  is 100 times faster than elder metal   Team Zopherus of Rogers, AR won first
         rently producing aftermarket parts us-  printing machines.            place in the level 1 competition of Phase
         ing the AM method which is more cost-  Considerable focus has been given to   3 for NASA’s 3D-Printed Habitat Chal-
         effective than starting up old production   3D printing with concrete and similar   lenge to fabricate subscale habitats. The
         lines that no longer produce the part.   materials in recent years. EMJ Corp.   $2,000,000 prize money for winners of
         One new component which is manufac-  has teamed  up with Branch Technol-  Phase 3, building a full-size dwelling,
         tured is a complex gas turbine nozzle   ogy, a Chattanooga, TN-based pioneer   is underway. The goal is to eventually
         used in their production equipment.  in 3D printing technology, to build the   house human explorers on the planet. I
           It is becoming cheaper and easier to   world’s  first  1000-square-foot,  free-  guess the sky is no longer the limit! WRN

         16     Wire Rope News & Sling Technology   February 2019
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