8/18/16

MET 328 Class Credit Subtractive Manufacturing Project

Joseph Legan

Executive Summary

This project is being performed in an effort to use life experience and experience gained from an internship as a substitute for the MET 328 class.The purpose of this report is to document the processes and technologies that can be used in modern subtractive manufacturing.

This project used a 3D Systems Capture scanner that uses white/blue light to digitize an artifact. This was followed by the use of Geomagic Design X to manipulate the scan data and to model the solid. The last software used was Surfcam Traditional 2016 R2. This is a CAM software that is more closely related to Mastercam than the new Surfcam Evo. Originally Surfcam Evo was going to be used for this project. In an effort to show an entry level working knowledge of a CAM software had been achieved, a decision was made to use the traditional version instead.

This project is an example of some of the technologies and their respective processes that are available to the manufacturing industry. The scanning and modeling processes are not exclusive to subtractive manufacturing and are often used in additive as well. I believe that this project has been a success in demonstrating thoroughly the technologies and processes used.

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Introduction

This project is being performed in an effort to use life experience and experience gained from an internship as a substitute for the MET 328 class.The purpose of this report is to document the processes and technologies that can be used in modern subtractive manufacturing. More specifically the processes of reverse engineering a given artifact, modeling a solid and using a CAM software to create a G-Code. This project used a 3D Systems Capture scanner that uses white/blue light to digitize an artifact. This was followed by the use of Geomagic Design X to manipulate the scan data and to model the solid. Then Surfcam Traditional 2016 R2 was used to create the G-Code for the artifact.Each of these steps is covered in more detail in the following section.

Procedures

The process involved in this project have been segmented into 7 functions. These are:

1. Scanning the artifact2. Mesh manipulation3. Modeling a solid from the mesh4. Preparation of required views, fixtures and tooling5. Defining machining steps as driven by part geometry, machine capability, and tooling6. Tool path verification7. Post processing and G-Code creation

The first step to all of this is setting up the scanner. The scanner chosen for use with this artifact, a remote oil filter base, is the 3D Systems Capture scanner. The Capture scanner is a desktop scanner that is intended for use with items no larger a softball or large grapefruit. It uses white and blue light displayed in a series of patterns along with 2 cameras to digitize portions of the artifact. After each image is captured a synced turn table rotates the artifact to next position and the process is repeated.The actual steps used for this project are fully defined in the Additive Manufacturing Report that has been submitted as well.

The next step or process is manipulating the meshes of the individual scans. This must be done in order to combine the data from multiple artifact positions into a single cohesive mesh. There may be as few as 2 artifact positions and up to as many as needed for the scanner to fully digitize the artifact. For this artifact a total of 3 scans were required. Again the actual steps used are fully defined in the Additive Manufacturing Report that has been submitted as well.

The next process is the modeling of a solid for use in later procedures. The actual steps used are summarized in the Additive Manufacturing Report.

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The remaining processes all use the Surfcam Traditional 2016 R2 software.

The first operation, after opening the software and loading the part file, is to prepare additional C-Views that are needed for use in machining steps. This is done by referencing the geometry of the desired face and assigning it as a new orthogonal view. Theses C-Views are really new coordinate system references for use with specific fixtures and operations. A picture guide with captions for creating C-Views is in the Appendix.

For this particular model, a remote oil filter base, a total of 3 additional views are required. Along with the 3 additional views a total of 6 fixtures would have to be created. This is due to the part geometry and the limitations of a 3 axis CNC mill. For this reason, we have to assume that the workpiece and fixtures are being mounted to a sine table and that the axis of rotation of the table matches that of the work piece. The fixtures have not been designed or defined as that is believed to be beyond the scope of this project. A picture guide of the each required fixture view is located in the Appendix.

Next the tooling required needs to be selected and assign tool locations. The tooling required for the project are assigned as follows:

1. 0.5” End mill2. 1.0” Carbide insert face mill3. 0.375” End mill4. 0.375” 118 degree split point mill5. 0.125 End mill6. 0.125 Ball mill

The tooling is described in depth on the set-up sheet that is located in the Appendix.

The next process is the defining of the machining operations. Before each operation can be defined by geometry a fixture position and tool must be selected. In the process of defining the first operation, the size and type of the stock is automatically determined by use of a bounding box. The order of operations is as follows.

Fixture Position 1

Rough cut of the base – Tool 1 Final cut of the base – Tool 1 4 pockets finish cut – Tool 1 Central hole finish cut – Tool 1

Fixture Position 2

Right angle finish face mill – Tool 2 Right Angle hole contour finish mill –Tool 1

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Fixture Position 3

Left angle face mill – Tool 2 Left angle hole contour finish mill – Tool 1

Fixture Position 4

Front contour finish mill – Tool 1 Rear contour finish mill – Tool 3

Fixture Position 5

Front pressure/temperature port hole operation – Tool 4

Fixture Position 1

Rear mounting hole finish mill – Tool 5 Rear mounting hole finish mill – Tool 5 Rear mounting base profile contour finish mill – Tool 1 Mounting base pocket mill – Tool 5 Mounting base pocket mill – Tool 5

Fixture Position 6

Bottom oil path 3 axis Z finish mill – Tool 6

Each tool path is pictured individually in the Appendix.

The next process involved is the verification of the toolpath. This ensures that the operations are being executed in the desired order and to the correct geometry. The Surfcam software has a feature that automates the entire sequence. Pictures of the automated verification are listed in the Appendix.

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Once the tool path has been verified, the final steps are the post processing and the creation of a G-Code. The post process is an adaptive process that conditions the G-Code for use with each specific CNC machine. A CAM software with a strong post processing utility can alleviate the need to manually edit the NC code, will support most or all the features of the selected CNC machine and verifies that the tool path data will not damage the CNC machine.

The CNC machine chosen for use with this project was the FANUC 15MB. The actual G-Code is an attached file as well as a text version of the code. In the Appendix there is a picture of the back plot that illustrates the execution of the G-Code.

Data

The data for this project is the actual G-Code file. It could be used with a FANUC 15MB CNC machine and the appropriate workpiece, fixtures and tooling to create a finished product.

Results/Analysis

The results of this project is the G-Code. The pictures used are done so in an effort to document a digital process contained within a closed computer system, a difficult task to do when the audience may not have access to the software used in order to verify the product.

Conclusions

I feel as though this project has been a success. The creation of the final G-Code product could have been done in fewer steps by the use of automated options within Surfcam. This was avoided when possible to display a working knowledge of the basic steps of traditional CAM software. Having only dabbled with CAM software before this project, it has been an intensive learning experience.

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Appendices

Create additional C-Views

Select the Create tab and then from the drop down menu select View. Next, select the 3 Points method.

The first point will represent the intersection of the X and Y axis, the 2nd is positive X, and the 3rd

is positive Y. The Z axis will be normal to the new reference plane.

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The new plane is created and with it an associated C-View for use with specific operations.

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Fixture ViewsAssume that you, the viewer, are the spindle of the mill looking along the Z axis towards the workpiece.

Fixture 1

Fixture 2

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Fixture 3

Fixture 4

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Fixture 5

Fixture 6

Tool Setup Sheet

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See the attached PDF document of the same name.

Tool Paths

Tool path 1

Tool paths 2 and 3

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Tool paths 4 and 5

Tool paths 6 and 7

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Tools paths 8 – 10

Tool paths 11 and 12

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Tool path 13

Verification of tool path.

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G-Code Back Plot

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