Sunday, October 15, 2006
1:30 p.m. to 5:50 p.m.
Design, Fabrication and Implementation
of Kinematic Coupling Technology
Martin L. Culpepper (Massachusetts Institute of Technology)
Precision engineers face a constant battle to provide
practical fixturing technologies for experiments and manufacturing processes.
It is important for them to be able to identify appropriate fixturing
technologies and then design, fabricate and implement these technologies.
This tutorial will cover the concepts and theory which govern how kinematic
couplings/fixtures are designed, manufactured and best-used in practice.
Emphasis is placed on deterministic modeling of performance (accuracy,
precision and stiffness) and hands-on experiments. The tutorial consists
of four sections:
(1) Passive alignment [1 hour]:
Covers the concepts and theory which govern the design and optimization
of kinematic couplings. We will examine:
(a) How to design coupling constraints: selecting the appropriate number,
location, orientation, and geometric/material properties of constraints
(b) Factors that limit coupling repeatability and accuracy: surface
finish, thermal errors, variable loading, friction and wear
(2) Active alignment [1 hour]:
Many emerging applications require nanometer-level accuracy and precision.
This can be achieved by incorporating mechanisms, actuators and sensors
which work together within a fixture to actively correct misalignment
errors. We will cover the fundamental concepts and the theory which
govern the kinematic motions of active fixtures, fixture performance
and the choice of actuators and sensors.
(3) Design simulators [0.5 hours]:
Participants will learn how to use simulation tools (Excel spread sheets)
to design/optimize passive and active kinematic couplings. Tablet PCs
will be provided for the purpose of this exercise. The simulation results
obtained in section 3 will be compared with experimental results obtained
in the following section.
(4) Hands-on experiments [1.5 hours]
Experiments will be run to demonstrate the proper use of these technologies
and to enable attendees to gain hands-on experience with the technologies.
Exercises will explore concepts such as stiffness, repeatability, effect
of lubrication, effect of preload, order of engagement.
Due to a family scheduling
conflict, Alex Slocum will not be able to be at the tutorial on Sunday;
however, he will be at the conference Monday through Wednesday and would
be happy to meet with those who in addition to learning the tutorial
material that will be presented by Martin Culpepepr, would like to meet
to discuss a particular application.
