Lucas Shaw and Prof. Jonathan Hopkins show the micro-architecture of an actively compliant material. Micro-actuators within the unit cells of an assembly are coordinated to reshape the assembly as desired. This was presented as part of the 2015 ASME Design Engineering Technical Conferences in Boston, MA, August 2-5. The video below shows what this assembly can do.
Lecture notes on specific topics.
Nicholas Bodley sent me to www.maritime.org for information about the MK.1 mechanical computer that he used as a Navy Fire Control Technician during the Korean War. Just the schematic of its operation is a dizzying flowchart.
A description of the mechanical components of this computer system can be found in the manual Basic Fire Control Mechanisms (62.7MB). It is an excellent description of the use gears, cams and linkages for computation.
Select this link, Four-bar linkages, for a Geogebra book that illustrates linkages ranging from a lever to a crank-rocker that open a door. This includes the construction of a four-bar linkage that coordinates the open and closed positions with specific input crank angles, called a four-bar function generator. The iPad application, MechGen FG, computes four-bar function generators for five coordinated values of the input and output cranks.
Profs. Carl Nelson and Anurag Purwar organized a Summer School on Kinematic Theory at the University at Buffalo, New York as part of the 2014 ASME Design Engineering Technical Conferences. Please select this link to get access to all of the talks: Kinematics Summer School.
My lecture on the synthesis of six-bar and eight-bar linkages is the third item on the playlist.
You can access a pdf of my talk at the link: Synthesis of Planar Six-bar and Eight-bar Linkages.
Among these is a nice presentation by Anurag Purwar on Quaternions and Clifford Algebras.
Please select this link to open the Geogebra Book containing constructions of a number of interesting linkages. This is an introduction to the useful movement available with articulated systems.
Until yesterday, my iBooks Introduction to Theoretical Kinematics and Kinematics and Polynomials were available only on the iPad, but now with OSX Mavericks they are available on any Mac. Please give it a try. You can download a sample at this link: Kinematics and Polynomials sample.
My iBook Kinematics and Polynomials is now available for preorder on iTunes. You can see a preview at this link. At 75MB it is considered a relatively large download.
The goal is a presentation of the analysis and synthesis of kinematic systems that relies on the theory of polynomials. I wanted to include some Mathematica code by means of video screen capture and some animations. The iBook format makes this convenient, however the size of the document increases rapidly with each video.
Currently, it can only be seen on an iPad, but this is supposed to change soon, because the OSX Mavericks operation system is to include an iBooks application.
My latest attempt at ePublishing is an iBook called Kinematics and Polynomials in Brief. It will be available on October 1, 2013. It is about 50 pages and includes six short videos, which unfortunately add up to about 75MB. This is about three times the size of Introduction to Theoretical Kinematics, though about half the number of pages. It is also about six times what is recommended for a book download.
The extra MB arise from short videos of Mathematica algorithms that perform example calculations presented in the text. Actually, most of the videos show me silently executing the Mathematica commands, but I do talk in two of them, which significantly increases their size. If you are interested in the Mathematica files, please contact me.
Our paper Numerical Synthesis of Six-bar Linkages for Mechanical Computation provides the mathematical theory that underlies the synthesis of a six-bar linkage with an input-output relationship that approximates a specified function. This describes how the Stephenson III six-bar linkage that sets the elevation for a ballistic trajectory was designed.