‰  NOW 30 WPM  ‰  TEXT IS FROM JANUARY 2016 QST  PAGE 34‰

USES A TECHNIQUE CALLED FUSED DEPOSITION MODELING, OR FDM, A VERY SIMPLE
ADDITIVE PRINTING PROCESS THAT HAS BEEN AROUND SINCE THE 1980S.  A STRAND
OF PLASTIC IS FED INTO AN EXTRUDER THAT HEATS UP TO ROUGHLY 212 C.  I USED
ABS PLASTIC, THE SAME PLASTIC THATS USED FOR JUST ABOUT EVERY PIECE OF
CONSUMER ELECTRONICS IN YOUR HOUSEHOLD.  THERE ARE MANY OTHER KINDS OF
PLASTICS TO CHOOSE FROM, RANGING FROM SOME MADE FROM RECYCLED MILK
CONTAINERS TO PLASTIC COMPOSITES COMBINED WITH WOOD OR COPPER THAT CAN BE
SANDED OR EVEN BUFFED TO A SHINE.  THE PLASTIC IS FED THROUGH THE EXTRUDER
BY A SMALL GEAR DRIVEN BY A STEPPER MOTOR ONE OF MANY IN THE PRINTER.  THE
MELTED PLASTIC IS EXTRUDED THROUGH A VERY SMALL HOLE ONTO A GLASS BED THAT
IS HEATED TO 90 C.  THE HEATED BED PREVENTS THE PLASTIC FROM COOLING TOO
QUICKLY AND POSSIBLY SHRINKING, ULTIMATELY WARPING AND RUINING YOUR PRINT.
THE PLASTIC HARDENS ALMOST IMMEDIATELY AND THE FIRST LAYER OF THE PRINT IS
FORMED.  THE EXTRUDER MOVES ON THE X AND Y AXES, AND THE HEATED GLASS BED
MOVES ON THE Z AXIS.  AS EACH LAYER IS EXTRUDED, THE Z AXIS MOVES DOWN,
ANYWHERE BETWEEN 100 400 MICRONS IN THE CASE OF MY PRINTER, WHICH YOU
‰  END OF 30 WPM TEXT  ‰  QST DE W1AW  ƒ