Carbon Fiber Placement Heads

      An Automated Fiber Placement (AFP) head is a piece of aerospace manufacturing equipment used to deposit uncured composites onto a mold.  The AFP heads carry spools of material ranging from 1/8” wide to 1/2” wide tapes.  Each head contains its own electrical, pneumatic and controls system and can be mounted to a gantry machine or industrial robot arm.  
       I worked to design and improve mechanical systems on the creel and the process ends of these end effectors.  I also worked to support legacy AFP heads used in production facilities around the world.
       Because of each customer’s unique application, each new project involves a large amount of design changes to these heads.  I lead a team of six engineers to create a new AFP head for the National Composite Centre (NCC) in Bristol, UK.  This project involved adapting the widest format material (1/2”) to the smallest head format (8-spools) in order to fit the head inside a female tool. The NCC also required the integration of a xenon flash lamp heater in addition to a standard infrared heater. 
      In order to meet these specifications we needed to design an almost completely new head.  My team and I took advantage of this opportunity to correct many constraint problems and inconveniences which persisted on older AFP heads.  After completion, these designs were quickly propagated to four new projects for other customers and have become a standard offering for Electroimpact.  
       In addition to design work, I was responsible for some aspects of the construction and commissioning of AFP systems.  Troubleshooting the problems seen on this equipment requires intimate knowledge of the mechanical, electrical, pneumatic, and controls systems and how they interact with each other.  Through many cycles of design, testing, delivery and support I have learned how to better design for the whole life  cycle of a product.    ​

Robotics Controls and Programming​

      The Automated Fiber Placement (AFP) heads and Kuka robots I worked with are controlled with Seimens PLCs, CNC, and a custom built HMI.  As an engineer working on the development of the AFP heads, one of my responsibilities was to commission and test the entire AFP system before it was sent to the customer.  This commissioning involved setup of the robot's CNC and PLC, setup of the head's PLC and integration of new equipment into the controls system.  
      For example, one of the AFP heads I designed featured a new infrared heater design along with new current regulators to power the heater.  To insure consistent heat was applied to the carbon fiber tape at a variety of different running speeds I had to characterize the heat output of the four separate infrared emitters.  I did this by correlating the commanded power to the current regulators, to the temperature of the carbon fiber, measured with thermocouples, at a variety  of different speeds.  This experiment gave me the desired power command at each speed.  With that knowledge I wrote a PLC function which controlled the heaters output based on the speed of the robots tool point. 
      Once These systems were completely up and running, I would program part files and macros to test the functionality.  Vericut software was used to generate tool paths and event commands from 3d cad files of a part.  Once I created a program I would use a python scrip to edit the program to optimized machine motion and otherwise tailor a program for testing. 
      I used the Vericut programing software to run simulations of part builds.  These simulations were used to estimate build times for customers, optimize robot motion, and ensure that there were no collisions or limits in the program. 


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End Effector Stands

​      One important feature of AFP systems is that the end effectors can be quickly placed into a stand and exchanged for a different end effector.  Some of these stands move or rotate the end effector for operator or maintenance access. 
       I have designed several of these stands for different end effectors.  In general, the stands consist of large steel weldments which are anchored into concrete.  The weldments are built from tube steel and brake formed steel sheet.  The sands need to repeatably locate the end effector for pickup and drop-off.
       For one project I designed a stand which would lift a 1,500lb end effector to a position where it could be picked up by a gantry  machine.  My design uses a servo driven acme screw to lift the end effector.  Linear rails and bearing cars were used for accurate and repeatable positioning.   The structure was required to withstand a strong earthquake without falling over.