Project Scope

        Design and build a test fixture that will allow for measurements of contact forces and contact loop resistances when electrical contact springs interact with pins.  Each spring is positioned on a collar, see Figure 1, and stacked on top of other collars which rotate on a double D-shape shaft, see Figure 2.  The springs have two wipers that will contact a pair of pins after some initial rotation and the pins spherical ends are 180 degrees apart,  See Figure 3.  The test fixture will need to support the double D- shape shaft along with the spring/collar assemblies and house the 20 pin setup.

                                    

  Figure 1.  Spring and Collar                    Figure 2.  Spring/Collar/Shaft Assembly

Figure 3.  Spring

 

    Important Objectives

1.  Fixture should allow for any number of pins 1-10 to be tested and provide easy access for insertion and replacement of pins

2.  Rotate double D-shape shaft with assembly of parts in five degree increments

3.  Contact forces must be monitored and recorded throughout the contact cycle

4.  Measure contact loop resistance

5.  Test fixture should be robust and allow for visibility of spring and pin interactions