Austin Northcutt

-Assignments-

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Assignment 5 - Components

Problem Statement:

The wiring harness for my engine needs to be easily removed for service in the future.  It also aids in the process of removing the motor if I ever find the need to.  This device needs to provide a way to quickly disconnect the 60 pin wiring harness from the cabin of the car. This particular design uses the force from an internal spring/wavy washer in the assembly to lock the plug to the receptacle.  There are many problems that can arise from this.  If the plug is not inserted in a specific orientation the pins and corresponding sockets will not be lined up correctly and could cause damage. 

Assumptions:

-Two main components: The Plug and the Receptacle

-Assembly will see vibrations from the car and engine

-The cannon plug can only attach in one orientation with the use of guides.

-The plug will require 1/3 of a turn to release from the receptacle.

-Will see a slight amount of weathering/moisture.

-Friction between the plug collar, plug, and the receptacle during mounting.

Gantt:

           

Decision Matrix:

-Based off the results of the decision matrix, I will be going more in depth into the module that incorporates a spring loaded collar.  The criteria I chose were all weighted on how important they were to the main concept.  The ranking scale 1-5, 5 being the excellent,  shows how well the module holds up under the given criteria.

Components:

--Main Assembly:

--Plug Assembly:

--Receptacle:

-The receptacle is mounted to the firewall of the engine bay and is static. This houses all the pins for the interior side of the wiring harness.  There will be a single guiding groove cut into the inner diameter to ensure the plug can only attach one way. The three guiding cylinders on the outside diameter will be grabbed by the collar to guide the plug into place laterally.

--Plug Core:

                -The plug core is main portion of the plug assembly.  It houses the necessary pins on the engine side of the harness that will be mated to the receptacle.  The larger circular rib extruded on the outer diameter serves as the spring seat as well as the collar retainer. 

       

--Plug Collar:

The collar drives the locking mechanism in the main assembly.  This is mounted on the plug core and is able to rotate freely around the core.  Guiding grooves cut at an angle on the inside diameter of the plug. These grooves serve as guides when the collar rotates around the receptacle’s cylinders.  As the collar rotates around the receptacle, it will draw the core in horizontally to mate to the receptacle.  No rotation is occurring from the core, only the collar.

--Wave Washer:

 A thin wavy washer serves as the spring force to keep the two halves mated together in the final assembly. It is sandwiched between the plugs core and the collar.  As the collar is rotating about the receptacle it will laterally bring the core in and compress this spring.  Once the guiding cylinders on the receptacle align with the holes on the collar, the spring will force the collar back, locking the assembly together. 

           
                 

Calculations:

                -There were few calculations that were needed to be derived but the main things that required them were the wave washer given force, mass of the objects, and the torque required to release and tighten the mechanism.
                -The Wave washer spring rate was simply found using Hooke's law, F = -ks. 
                -The mass of the objects were calculated using P = m/v.
         -The torque required was found using dynamics. Friction constant of polished steel on steel, normal force, spring force, were all either givens or calculated.
               

Lessons Learned:

                -How to render in Solidworks.
                -Material selection based off criteria is now a very clear process.
                -Material selection based of elasticity/spring rate is now clear.
                -How to pin motorsport connectors.  Began pinning my connector on the physical harness.                                        

Activity Log:

                -4/9 (9am – 1:00pm) :: Complete Decision matrix, update Gantt, and type up website stuff in word

                -4/9 (2:15 - 10pm)  :: Solidworks models and assemblies.

                -4/10 (2:00 – 4:00) :: Go in depth on formulas and decide on materials where needed.

                -4/10 (4:00 – 5:00) :: Mock up website and make sure all images are working

                -4/10 (7:00pm) :: Submit Website

Comments:

                William Hinson:
                    - Very organized assignment 5 flows well.
                    - My only complaint is there is no final assembly.  If someone who was not following your portfolio were to look at your assignment, they wouldn't know what it is.
                   

                James Neal:
                    - Great work, It was cool seeing the motion study of the part.
                    - I like how in depth you were with the material selection of 316 stainless.