Engineering Commons^™

Feasibility And Uncertainty Evaluation Of Sequential Hybrid Manufacturing Using Optical Coordinate Metrology, Jake Dvorak

Doctoral Dissertations

Hybrid manufacturing has been suggested as a solution to global manufacturing challenges including stock availability, manufacturing costs, and difficulty in production of complex parts. However, feasibility and validation of hybrid manufacturing remain open research opportunities.

This research evaluates measurement uncertainty for optical coordinate metrology (OCM) within a sequential hybrid manufacturing (SHM) framework where a primary manufacturing process, a part geometry measurement, and a secondary manufacturing process are performed sequentially on optionally separate machine tools. In this work, an additively manufactured preform is produced, the part geometry is measured using structured light optical coordinate metrology, and the final geometry is obtained …

Moringa Connect: Design And Fabrication Of The Drum For A Moringa Leaf Dryer Prototype, Braden Deck

Construction Management

Moringa Connect, founded in 2013 by MIT alumnus Kwami Williams, supports over 5,000 African farmers, primarily in Ghana, by providing a direct sales, manufacturing, and shipping platform for nutrient-dense moringa leaves. Despite significant social and economic benefits for the local farmers, the current drying process in Accra, Ghana, is inefficient, requiring extensive human handling. To address this, a team of five Cal Poly students partnered with Moringa Connect to design a prototype rotating hopper to streamline the drying process and reduce production costs. The project faced numerous challenges, including material sourcing constraints in Ghana and the need for extensive fabrication …

Cam And Design For Manufacturing: Developing A Project-Based Learning Course, Stephen Pierson

Mechanical Engineering Undergraduate Honors Theses

To effectively serve student career success, mechanical engineering programs must teach students how to account for manufacturing considerations in design. Despite this, manufacturing education is a glaring area of need in current engineering curricula. In fact, basic manufacturing knowledge is one of the only hard skills consistently ranked as one of the greatest weaknesses of mechanical engineering hires in surveys of industrial employers over the last few decades. Without radically changing departmental curriculum to include more emphasis on design-build projects, one solution to combat this is to incubate a lab course in mechanical engineering programs in which undergraduates would practice …

Milling Stability Map Identification And Machining Parameter Optimization Using Bayesian Inference, Aaron William Cornelius

Doctoral Dissertations

This dissertation describes a physics-guided Bayesian learning approach for statistically modelling and optimizing machining processes under a state of uncertainty. This approach uses a series of automatically-selected cutting tests to refine uncertainties about the machining system's dynamics and cutting force and identify higher productivity cutting parameters. The algorithm is evaluated experimentally and compared to the cutting tool manufacturer’s recommendations, both in laboratory conditions and in an industrial setting to optimize the machining process for a large aluminum component. These results show that the proposed Bayesian model can quickly identify both highly-productive machining parameters and accurate information about the underlying system …

Radio-Controlled Baja Car, Jaxx Brown

All Undergraduate Projects

The Central Washington University RC Baja competition tests students’ skills in engineering in a matter of ability to design, construct and test an RC car. The objective of this senior project is to manufacture efficient suspension and steering systems for an RC vehicle and compete at the end of the school year against other students’ vehicles. Two races will be conducted during the competition, the RC vehicle will compete in a slalom-and-sprint and a Baja. Using more than one manufacturing method and material was expected of students to create the steering and suspension systems. Through CAD software and 3D printers …

Path Planning For Additive Manufacturing Of Wire Arc Additive Manufacturing And Blue Light Fringe Projection Scanning, Tiffany Patricia Quigley

Masters Theses

Current methods of manufacturing large scale parts can take up to six months to generate the objective product. The objective of the wire arc additive manufacturing (WAAM) hybrid cell is to significantly reduce lead time associated with large scale parts. The WAAM process utilizes a 6 degree-of-freedom (DOF) robot manipulator in addition to a 2 DOF part positioner. 5 degrees of freedom are necessary for an effective WAAM process, leaving 3 DOF as redundant in this cell. This thesis serves to prove successful implementation of redundant kinematics on a WAAM robotic system. This is accomplished by maintaining a gravity aligned …

In-Situ Characterization Of Surface Quality In Γ-Tial Aerospace Alloy Machining, David Adeniji

Theses and Dissertations--Mechanical Engineering

The functional performance of critical aerospace components such as low-pressure turbine blades is highly dependent on both the material property and machining induced surface integrity. Many resources have been invested in developing novel metallic, ceramic, and composite materials, such as gamma-titanium aluminide (γ-TiAl), capable of improved product and process performance. However, while γ-TiAl is known for its excellent performance in high-temperature operating environments, it lacks the manufacturing science necessary to process them efficiently under manufacturing-specific thermomechanical regimes. Current finish machining efforts have resulted in poor surface integrity of the machined component with defects such as surface cracks, …

Displacement-Based Dynamometer For Milling Force Measurement, Michael F. Gomez

Doctoral Dissertations

This project will study the design and testing of a low-cost dynamometer for milling dynamic force measurement. The monolithic design is based on constrained-motion/flexure-based kinematics, where force is inferred from displacement measured using a low-cost optical interrupter (i.e., a knife edge that partially interrupts the light beam in an emitter-detector pair). The time-dependent displacement of the dynamometer’s moving platform caused by the milling force is converted to the frequency domain, multiplied by the inverse of the dynamometer’s ideally single degree of freedom (SDOF) frequency response function (FRF), and converted back into the time-domain to obtain the time-dependent cutting force. The …

Design And Fabrication Of Invar Layup Tool Molds Using Additive And Subtractive Manufacturing, Matthew Lamsey

Masters Theses

The development of novel additive manufacturing technologies, such as Wire Arc Additive Manufacturing (WAAM), has opened the door for the fabrication of complex part geometries that could not be achieved with traditional manufacturing methods. Best practices for designing parts for fabrication with WAAM are still in their infancy. This thesis presents a novel design and fabrication framework for parts created using WAAM, which was realized through the fabrication of two demonstration composite layup tool molds. The framework includes design principles for WAAM, finite element simulation of part performance, metrological analysis of printed preforms, and considerations for closely integrating the WAAM …

Identifying The Need For Trained Machinists In The Greater Tri-Cities Area, Bradley Stufflestreet

Electronic Theses and Dissertations

Machinists are skilled tradespeople responsible for running a variety of machine tools to produce precision components for end-users or use in other manufacturing. This project identifies the current and future change in the number of machinists in the Tri-Cities area, especially the five-county service area of Northeast State Community College. Using an industry survey, the need for machinists is identified and evaluated to understand local employers’ needs. The results indicate industry needs more machinist to keep up with demand, as 6 out of 14 companies have open positions and, 8 reported difficulty filling openings. Furthermore, most companies are growing or …

C6 Wheels, Samuel L. Pizot, Luke Martin, Josh Warner, Jonah Levis

Mechanical Engineering

This document details the C6 Wheels project being undertaken for senior design. The objective is to design and manufacture carbon fiber reinforced polymer wheels for the Cal Poly Formula Society of Automotive Engineers (FSAE) team. The wheel shells will be used on FSAE’s competition vehicles. FSAE requested the wheels to improve the handling characteristics of their vehicles by reducing the unsprung and rotational mass. They have attempted carbon fiber wheels previously but have not yet run any on their vehicles. FSAE specifically proposed the design of carbon fiber shells with an aluminum center as opposed to full carbon fiber wheels …

Custom Designed Wall Mounted Shop Crane, Bradley Lewis

All Undergraduate Projects

The objective of this project was to design and fabricate a custom wall mounted jib crane to specific, non-standard dimensions. The crane was designed to be industry rated for 2000 pounds, rotate at least 180 degrees, and be designed to have a maximum boom length tailored to the specific installation site. Two potential installation sites and purposes were selected for construction: inside the bay doors of a fabrication shop, intended to transfer large pieces of material to and from a plasma table, and inside a car maintenance garage, intended to lift and remove engines and transmissions from cars.

Design of …

Investigation Of Chip-Form And Tool-Wear In Turning Of Hardened Af9628 Alloy Under Various Cooling And Lubrication Conditions, Jason Wolf

Theses and Dissertations--Manufacturing Systems Engineering

Next generation defense and commercial applications for structural steels require new alloys that eliminate or reduce critical elements from their composition to lower cost and improve manufacturability, while maintaining or exceeding high strength and toughness requirements. A new alloy, denoted as AF9628, has recently been developed for this purpose and its manufacturing characteristics and the material response in component manufacturing must be fully understood.

In the present study, hardened AF9628 alloy was turned with a coated carbide cutting tool under fixed cutting speed, feed rate, and depth of cut parameters. This work focuses on chip-form and tool-wear analysis to understand, …

Enhanced Surface Integrity With Thermally Stable Residual Stress Fields And Nanostructures In Cryogenic Processing Of Titanium Alloy Ti-6al-4v, James R. Caudill

Theses and Dissertations--Mechanical Engineering

Burnishing is a chipless finishing process used to improve surface integrity by severe plastic deformation (SPD) of surface asperities. As surface integrity in large measure defines the functional performance and fatigue life of aerospace alloys, burnishing is thus a means of increasing the fatigue life of critical components, such as turbine and compressor blades in gas turbine engines. Therefore, the primary objective of this dissertation is to characterize the burnishing-induced surface integrity of Ti-6Al-4V alloy in terms of the implemented processing parameters. As the impact of cooling mechanisms on surface integrity from SPD processing is largely unexplored, a particular emphasis …

Analysis Of The Integration Of Dfm Techniques And Effective Machining Parameter Selection In Metal Parts Manufacturing, Omar Ahmed Al-Shebeeb

Graduate Theses, Dissertations, and Problem Reports

This dissertation investigates the minimization of part design with self-locating features. The research focuses primarily on self-fastening characteristics, standardization of parts, and minimal use of fasteners. Further, the present research studies the design for base parts in the construction of a moving joint system, in order to locate potential part and system design improvements. This process may then be extended to industrial applications in the manufacturing industry. Relatively little work to date has examined the significance of Design for Manufacturing Techniques (DFMT), with their inherent machine element systems and machining parameters to investigate which DFMT has the most influence on …

Hybrid Processes In Material Removal Of Hard And Brittle Materials, Hossein Mohammadi

Dissertations

New technologies demand new materials with better mechanical, optical, and thermal properties. Materials that are light weight, strong with high resistance to high temperatures, and compatible with a predetermined condition. Such materials usually are challenging to manufacture and process compared to widely available materials such as metals. Ceramics and semiconductors are considered extremely hard and brittle, making them very difficult to cut and manufacture. The other major and fast-growing type of materials are composites (including Ceramic Matrix Composites, CMC) that are also considered very challenging to machine. All these materials have many applications in major industries (i.e. electronics, aerospace, optics, …

Cal Poly Supermileage Drivetrain, Michael Bolton, Justin Miller, Heather Fields

Mechanical Engineering

The following report details the full design process used by the Cal Poly Supermileage Drivetrain (CPSMD) Senior Project team in designing a new drivetrain system for the Cal Poly Supermileage Vehicle (SMV) Team. Included is the development stages of each component, the manufacturing of our parts, the final solution’s assembly, the testing of the project, and the results from the 2018 Shell Eco-Marathon Competition. After collecting data from several tests, only the final drivetrain efficiency and final sprocket alignment remain unknown. Otherwise, the project came in under budget, within our weight tolerance, and met all the other design objectives. The …

Cwu Bottle Opener Manufacturing, Austin Sanford

All Undergraduate Projects

Previous students from the Mechanical Engineering Technology program came up with a method to help raise funds and awareness for the program. The idea was to manufacture and sell CWU bottle openers. However, a more efficient manufacturing method was needed. The aspect of the process that would have the most impact on the manufacturing time and material efficiency was the CNC machining of the parts. There were many potential variables to change to improve the process, but the main changes were to the cutter speeds and stock material size. Consequently, the changes made to stock material size reduced the number …

Effect Of Microstructural Features On Steel Machinability, Mark C. Emmendorfer

Masters Theses

Non-metallic inclusions can have a tremendous impact on the machinability of steel. Some oxide inclusions such as alumina, spinel, and other refractory abrasive oxide inclusions can have a detrimental effect on machinability. Modification of oxide inclusions by calcium treatment can promote the formation of low melting point oxides such as anorthite and gehlenite inclusions that can assist in chip formation and form a lubricating layer on the rake surface of the machine tool. MnS is known to be beneficial to improving the machinability of steel. They assist in chip formation by being heavily deformed in the primary shear zone. Sulfide …

Multi-Axis Machining Project Development, Ryan Patrick Blodgett, Andre Peter Rivera

Industrial and Manufacturing Engineering

Multi-axis milling is a manufacturing material removal process in which computer numerically controlled (CNC) tools cut away excess material through movement in four or more axes. Compared to traditional three-axis machining, multi-axis machining greatly increases the capability and accuracy of the CNC machining processes by reducing the amount of operations required to completely machine a part. Currently, the Industrial and Manufacturing Engineering Department at Cal Poly lacks an advanced CNC class that incorporates fourth and fifth axis CNC machining in the curriculum. This report describes the process behind creating a project for such a class. The class will demonstrate the …

Multi-Use Fireline Handtool, Bruce W. Bernard Jr

All Undergraduate Projects

A wildland firefighter is a valuable resource to protecting public lands and managing fuels. The many hand tools used by firefighters aid in their ability to complete any required tasks effectively. Several of the tools available are specially purposed for individually grubbing, scraping, or liming. A small squad of firefighters could become a more effective resource if the tools they carried could perform several of these purposes as one single tool. To improve the effectiveness of an individual on the fireline a multi-use hand tool was designed to include an axe for liming and a heavy duty scraper for grubbing …

Met 314 Torque Measurement, Jose Bejar

All Undergraduate Projects

As part of the Mechanical Engineering Technology program, students are required to take a Thermodynamics class. In this class one of the labs they do consists of an air motor running a water pump. The professor teaching that class wanted a device that would fit within the lab rig which would calculate the torque produced by the motor. Therefore this project consists of building a device that will allow the case (body) of the air motor to fully rotate opposite to the rotation of the shaft in order to measure the torque the motor produces at certain revolutions per minute. …

Design Of A Custom Software Application To Monitor And Communicate Cnc Machining Process Information To Aid In Chatter Identification, Valerie Pezzullo

All Theses

In any manufacturing environment, it is important to be able to monitor the Computer Numerical Control (CNC) machining process so that high quality parts can be produced in the least amount of time in order to be profitable. This involves acquiring the proper parameters needed from the machine's controller, which can prove to be difficult with proprietary machine tools that tend to limit access to the internal data collected by the controller. This closed approach to controller design also means that many technological advances that have recently become prevalent in society are not being adopted in the manufacturing industry, preventing …

Prediction Of Subsurface Damage During Machining Nickel-Based Superalloys, Yujie Chen

All Dissertations

Nickel-based superalloys are widely utilized in hostile environments such as jet engines and gas turbines due to their high resistance to oxidation, high corrosion resistance, good thermal fatigue-resistance and fracture toughness. Subsurface damage is typically generated during the machining of these materials, and in particular, ã'-strengthened nickel-based superalloys. The depth of the subsurface damage is a critical requirement specified by the customer. Therefore, it is critical to predict, measure and control subsurface damage.
This research specifically targets the development of a model to predict subsurface damage during the machining of ã'-strengthened nickel-based superalloys. To accomplish this, a modified Johnson-Cook model …

High Speed Turning Of Compacted Graphite Iron (Cgi) Using Controlled Modulation, Tyler Paul Stalbaum

Open Access Theses

Compacted graphite iron (CGI) is a material which emerged as a candidate material to replace cast iron (CI) in the automotive industry for engine block castings. Its thermal and mechanical properties allow the CGI-based engines to operate at higher cylinder pressures and temperatures than CI-based engines, allowing for lower fuel emissions and increased fuel economy. However, these same properties together with the thermomechanical wear mode in the CGI-CBN system result in poor machinability and inhibit CGI from seeing wide spread use in the automotive industry.

In industry, machining of CGI is done only at low speeds, less than V = …

Automated Digital Machining For Parallel Processors, Joshua Tarbutton

All Dissertations

When a process engineer creates a tool path a number of fixed decisions are made that inevitably produce sub-optimal results. This is because it is impossible to process all of the tradeoffs before generating the tool path. The research presents a methodology to support a process engineers attempt to generate optimal tool paths by performing automated digital machining and analysis. This methodology automatically generates and evaluates tool paths based on parallel processing of digital part models and generalized cutting geometry. Digital part models are created by voxelizing STL files and the resulting digital part surfaces are obtained based on casting …

A Study On The Feasibility Of Universal Chip Control In Machining, Thimmaiah Kumbera Ganapathi

Dissertations, Master's Theses and Master's Reports - Open

A novel solution to the long standing issue of chip entanglement and breakage in metal cutting is presented in this dissertation. Through this work, an attempt is made to achieve universal chip control in machining by using chip guidance and subsequent breakage by backward bending (tensile loading of the chip's rough top surface) to effectively control long continuous chips into small segments.

One big limitation of using chip breaker geometries in disposable carbide inserts is that the application range is limited to a narrow band depending on cutting conditions. Even within a recommended operating range, chip breakers do not function …

Model Identification, Updating, And Validation Of An Active Magnetic Bearing High-Speed Machining Spindle For Precision Machining Operation, Adam C. Wroblewski

ETD Archive

High-Speed Machining (HSM) spindles equipped with Active Magnetic Bearings (AMBs) are envisioned to be capable of autonomous self-identification and performance self-optimization for stable high-speed and high quality machining operation. High-speed machining requires carefully selected parameters for reliable and optimal machining performance. For this reason, the accuracy of the spindle model in terms of physical and dynamic properties is essential to substantiate confidence in its predictive aptitude for subsequent analyses.This dissertation addresses system identification, open-loop model development and updating, and closed-loop model validation. System identification was performed in situ utilizing the existing AMB hardware. A simplified, nominal open-loop rotor model was …

Multi-Sensor Optimization Of The Simultaneous Turning And Boring Operation, Erick Johan Deane

Electronic Theses and Dissertations

To remain competitive in today’s demanding economy, there is an increasing demand for improved productivity and scrap reduction in manufacturing. Traditional manufacturing metal removal processes such as turning and boring are still one of the most used techniques for fabricating metal products. Although the essential metal removal process is the same, new advances in technology have led to improvements in the monitoring of the process allowing for reduction of power consumption, tool wear, and total cost of production. Replacing used CNC lathes from the 1980’s in a manufacturing facility may prove costly, thus finding a method to modernize the lathes …

A Geometry-Based Motion Planner For Direct Machining And Control, Robert M. Cheatham

Theses and Dissertations

Direct Machining And Control (DMAC) is a new method of controlling machine tools directly from process planning software. A motion planning module is developed for the DMAC system that operates directly off path geometry without pre-tessellation. The motion planner is developed with the intent to process Bezier curves. The motion planning module includes a deterministic predictor-corrector-type curve interpolator, a dynamics limiting module, and a two-pass jerk-limited speed profiling algorithm. The methods are verified by machining an automotive surface in a clay medium and evaluating the resultant machine dynamics, feed rate, and chordal error throughout the machining process.