Flange Metric Tolerancing

Flange English Tolerancing

The front view is created first through the use of concentric circles using the respective dimensions with the CIRCLE command. The hole at the top is created using the CIRCLE command and patterned around the front view 8 times using the POLAR ARRAY command. The circle is positioned through the use of the centerline circle, which is drawn with the CIRCLE command in the centerline layer. The appropriate center lines are added to the circles using the CENTERLINE command and the TRIM tool. Certain circles are drawn with the CIRCLE command, but on the hidden lines layer, in order to symbolize hidden circles in this respective view.

Horizontal construction lines are now used on each significant point of the front view to begin creating the right section view. A series of LINE commands are used to create the geometry of the section view, both through the use of the horizontal construction lines and the horizontal dimensions. After the geometry is completed on the right view, add a centerline where the central holes exist, as well as the smaller holes at the top and bottom of the right view, using the CENTERLINE command. Additionally, for the sections above and below the holes at the center, add hatches to display a section view using the HATCH command. Ensure that all lines are in their respective layers and use the DIMENSION command to add all specified dimensions to each view, using the dimension layer. Now, add tolerances to the specific dimensions that are needed by selecting the dimensions and modifying their properties in the tolerance section. Additionally, add tolerances specific to the diagram referenced above for all the dimensions using the TOLERANCE command.

Overall, this part was quite simple to create, especially if the front view is created first. Since the 3D that was used for all the dimensions was cut to see the sectional view, it was much easier to interpret the dimensions. On another note, knowing that this part would have taken a fraction of the time to create in 3D-modeling software, it is very good practice in using the fundamental commands in AutoCAD.

retaining plate

The front view is created first through the use of concentric circles using the respective dimensions with the CIRCLE command. The hole at the top right is created using the CIRCLE command and patterned around the front view 4 times using the POLAR ARRAY command. The appropriate center lines are added to the circles using the CENTERLINE command. The right and left end of the largest circle are cut so that the distance between them is 4.320 in. In this instance, construction lines are very useful in accurately portraying the part itself since it can offset vertical lines to the exact cutting point. A cutting section line is created down the vertical center of the front view to set up for the section view.

Horizontal construction lines are now used on each significant point of the front view to begin creating the right section view A-A. A series of LINE commands are used to create the geometry of the section view, both through the use of the horizontal construction lines and the horizontal dimensions. After the geometry is completed on the right view, add a centerline where the central holes exist using the CENTERLINE command. For all the corners with a specific round value, use the TAN-TAN-RADIUS CIRCLE command at the edges and use 0.1 inches as the radius value, then trim the unneeded lines. Additionally, for the sections above and below the holes at the center, add hatches to display a section view using the HATCH command. Ensure that all lines are in their respective layers and use the DIMENSION command to add all specified dimensions to each view, using the dimension layer. Now, add tolerances to the specific dimensions that are needed by selecting the dimensions and modifying their properties in the tolerance section.

Overall, this part was quite simple to create, especially if the front view is created first. The use of construction lines is always helpful in creating features accurately without creating unnecessary lines. After all, the construction lines are their own layer and all the clutter can be removed upon completion of the drawing. It was very helpful that the drawing was symmetrical, so the work needed to make the part was cut in half.

Sprocket

Geneva Cam

In order to create the Geneva Cam part in Creo 3.0, you must open the AutoCAD drawing of the Geneva Cam in a .dxf extension. Before doing so, open the part as a “.dwg” file and insure that all endpoints of the arcs along the outside chain of the Geneva Cam are closed, as pointed out by the tutorial, in order to avoid future errors. From here, the drawing’s dimensions and all respective layers will be transferred to the Creo software. Once the part is imported, all the layers, except the object lines layer, must be removed for simplicity. This is done by going to the AutobuildZ tab and selecting the CLEAN UP command. From here, all colors are already selected, so select the apply button to cancel out all layers. However, the centerline layer still remains on the file. To remove this layer, move to the manual tab and check the box stating to remove by color. Label this layer as MISC and select one of the centerlines to get rid of them all. Next, select the VIEW SETUP command to set the front and right views. Before selecting the views, be sure to select “…” button to set the scale of the part as it may not be a 1.0 scale between AutoCAD and Creo. Select the 2.5 diameter dimension as a reference and specify its start and end points. The dimensional value and the measured value in the software will create a ratio that will fix the scale. From there, select the front and right views for their respective options and drag the cursor over that view to label it as front view and right view, respectively. From here, use the PART SETUP command to create a new part file based on the “.drw” file that has been modified and clean up. At this point, the PROTRUSION command can be used to create all the physical features of the part, starting with the Geneva Cam outline extrude, followed by the hub extrusion and the key hole extrusion cut. In each protrusion, make sure to specify the part you are extruding in the front view, then specify the starting plane and depth in the right view. After the model is fully developed, open it separately and add the fillet to the hub to finish the part using the FILLET command.

Overall, this part gave a great chance to become familiar with the AutobuildZ tab, which is not ordinarily used in Creo. It is also very convenient to be able to move an AutoCAD drawing to Creo, a 3D software, without having to remake the entire drawing or part. With that being said, this exercise provides a very practical use of Creo and AutoCAD, teaching one how to transfer an existing file between software.

Pipe Hanger

Bearing Design

All of the above drawings were created using AutoCAD 2017. Each of the drawing use similar commands to create the geometries. Examples of such commands are "circle", "line", "trim", "extend", "copy", "move", "rotate", "explode" and many others. AutoCAD was especially useful due to the use of layers, where each specific object in the drawing had a different color and line type that can be turned on and off. For the drawings above, green was designated for title blocks, blue for the object lines, purple for dimensions, cyan blue for hidden lines, red for center lines and gray for hatches, notes or construction lines. Construction lines were especially useful because they helped with creating right and top views from the original front view and could be turned off for clarity at any time. The AutoBuildZ feature was also used in Creo to import these drawings and convert them into 3D models right from the original drawing, such as the geneva cam.