September 7, 2011


This blog uses the following references: 1.) Manufacturing Engineering, “Masters of Manufacturing—Dr. Carl R. Deckard”, July 2011 and 2.) Rapid Prototyping—PDHonline by Bob Jackson.

Sir Isaac Newton once said “if we accomplish at all we do so by standing on the shoulders of giants”.   Engineering technology and scientific endeavor have always been dependent upon those discoveries preceding “great enterprise”.   My generation laughingly calls this kicking the can down the road.  There are many marvelous technologies that had to wait until other discoveries were made.  The i-PAD would be impossible without transistors; RFID (radio frequency identification) could never have been commercialized had “chip” technology not been available and rapid prototyping, specifically, selective laser sintering, would be just a great idea without computer aided design and parametric modeling.   Selective laser sintering (SLS) is an “additative” technology in which highly complex parts can be manufactured and prototyped from materials such as metal, plastic, ceramic, and sand. The material, in powdered form, is deposited on a platform, then a carbon dioxide (CO2) laser is used to selectively melt or sinter the powder into the desired shape for each layer. The layers are lowered on a platform, with loose powder around the growing structure acting as a support for the top powder layer. Computer programs slice the CAD three-dimensional model into layers approximately 0.001 inch in thickness to achieve the profile required by the design.  As mentioned, the platform is lowered by the height of the next layer and powder is reapplied. This process continues until the part is complete.   The strength and porosity of the material can be controlled by adjusting various process parameters, such as laser scanning speed and power. Products have ranged from turbine rotors to medical inserts.

Developed by Carl Deckard for his master’s thesis at the University of Texas, selective laser sintering was patented in 1989.    Dr. Deckard is one of those “giants” I would like to bring to your attention with this document.   Dr. Deckard, as much as any individual, was destined to be the developer of an innovative and transformative technology.  His statement—“as far back as I can remember, I wanted to be a scientist”, pretty much says it all.  That changed when Deckard’s father took him to the Henry Ford museum.  He was eight years old at the time.  “I decided that I wanted to be an inventor from that time on”. Not an easy task since you are looking for things that really do not exist.  During his grammar school years, he actively studied the lives of the great inventors and became very familiar with the patent process while working on a number of inventions himself.  Upon leaving high school, he decided he wanted to be a mechanical engineer.  He felt that profession was the closest thing to majoring in invention.   The timing could not have been better.  In the 1980s, computers and 3-D CAD were about to change the way parts and associated tooling were made.  “The hype in the early days of 3-D CAD was that you could go from a computer model to a CNC program in an automatic way.”  That really did not happen until some years later, but that was all the “buzz”.  Still, even using 3-D CAD, you had to go from the drawing to a casting or a forging or a CNC mill or lathe.  The process of going right from the parametric model to a completed prototype was not possible at the time.  This is where the genius of Deckard became apparent.  The very first thing he realized was that the process, to be successful, had to be addititive.  “With a subtractive process, there are too many geometric constraints and if you machine one area it affects another area”.  You have to have tool access for a subtractive process to be viable.  From this thought, he decided the process had to be an incremental addititive process in a regular sequence.   He experimented with sugar and salt and finally decided that using a two-powder approach would be very difficult and not yield the results he was after.  Those results were quality and attention to detail.   That is when he decided to lay down one power and hit it with a directed energy beam and that beam would be controlled by a computer.   He recalls that this was something that really could work and was worth putting effort into.    By the time he was accepted into graduate school, he realized that this could be a great graduate research project.  Vision and future came together at this point and he approached Dr. Joe Beaman, a University of Texas professor.  His “pitch”—to build three-dimensional objects from a computer model using layers of powder and melting those powders together with a directed energy beam.  The Mechanical Engineering Department at the University of Texas had just moved into a new building and there was money for equipment and tooling.  Deckard was told to “spec-out” the equipment he would need for the project.  This equipment included a 2-D laser scanning 30 frames per second.  As it turned out, he had made a fairly serious error in his calculations and re-speced the laser to a 100 watt YAG with galvanometer tracking.   He used, believe it or not, a Commodore 64 as his computer.  64K!  His program was hand-assembled and a whopping 153 bytes long.  The original setup proved the concept.  The first models were very crude but persistence yielded approval from the school to go forth and apply for a US patent.   During the early phases of his work he decided to commercialize the device but could not interest any large companies to finance the risk.   At this time, he began looking for partners to establish a start-up business and eventually was able to team up with B.F. Goodrich. The initial expenditure was $300,000.   This joint-venture yielded the very first commercialized laser sintering process and produced the SLS 125.   Since that time, there have been many developments and many iterations relative to the initial concept—all producing marvelous results and cutting the time to prototype from days, possibly weeks, to hours.  Even the most complicated model rarely takes over 72 hours to make.     

Let me now ask, do you know the following names—Justin Bieber, Kim Kardashain, LL Cool J, Beyonce?  You know these folks.  Granted, maybe great performers but, how much have they really contributed to society? Just how much?   OK, so why have you never heard, until now, of Dr. Carl R. Deckard or many of the other engineers, mathematicians, scientists, etc. who labor quietly following their passion.   We can change this and you are– right now.

Hope you have a great week—-Bob Jackson



  1. Its like you read my mind! You seem to know a lot about this,
    like you wrote the book in it or something. I think that you can do with some pics to drive the message home
    a bit, but instead of that, this is wonderful blog.
    A fantastic read. I’ll certainly be back.


    • cielotech Says:

      Hello Plush–Carl Deckard or Dr. Carl Deckard is one of the giants in engineering. He obtained his PhD by developing Stereolithography methodology. A great breakthrough. Really happy you enjoyed this one. Take care and please come again. Bob


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