In Mechatronics at San Diego State University, myself and one other member were assigned the task of 3D modeling O-Ring grooves in the 2019 autonomous underwater vehicle assembly. The objective of this project was to ensure that every seal on the AUV was watertight so that the electronics contained within the vehicle are not compromised by leakages. Completing this project involved these two major steps: Calculating O-ring groove dimensions and editing sweep cuts into the submarine assembly via SolidWorks.

​

Calculating Dimensions

​

A preliminary requirement for calculating the dimensions of a particular O-ring groove was knowing the thickness of the O-ring that would be used. This allowed for the appropriate gland width and depth to be determined, after accounting for the compression and expansion of the O-ring. The next step was sourcing a Buna-N O-ring from McMaster-Carr, that at 2%-5% stretch would fit in the groove that was created. An excel spreadsheet was used to simplify calculations and to document each O-Ring groove we completed.

​

3D Modeling

​

​The last step required using the calculated dimensions to convert the placeholder O-ring grooves (extrude cuts) within the SolidWorks submarine assembly into easily modifiable sweep cuts. Converting each placeholder groove into a sweep cut was done with a methodical, systematic procedure. The process began by identifying the placeholder groove of interest and opening the part in a separate SolidWorks document; this prevents us from running into in-context assembly errors. Within the part, the placeholder extrude cut object is deleted and replaced by a sketch representing the sweep path of the groove. Then, using depth and width calculated in the initial steps, a sweep profile sketch is made perpendicular to the sweep path. Finally, using the sweep profile and the sweep path as inputs into the swept cut feature tool, the desired O-ring groove is generated.  

​

Images of the excel spreadsheets used for O-ring calculations can be found below:

​