November 30 – December 3, 2004 ◊ Las Vegas, Nevada

Quick Spin in AutoCAD® Mechanical

Christiaan Bowen – Sellier Enterprises, Inc. Jim Swain – Synergis Technologies

MA21-1L Do you want to see if AutoCAD Mechanical is right for you? Take the software for a 90-minute test drive. See how much more productive you can be by checking out its design productivity tools including the remarkable 2D Hide, Power Dimensioning, ballooning, and parts lists. If you're already familiar with AutoCAD and would like to see what AutoCAD Mechanical has to offer, this lab with give you a hands-on feel for the software.

Topics Covered:

• Utilizing some of AutoCAD® Mechanical’s tools

• Learning how the structure catalog works by adding existing parts to the assembly

• Using the shaft generator to create a custom shaft

• Adding a standard part from the parts catalog

• Creating a screw connection

• Documenting an assembly

About the Speakers: Christiaan Bowen Christiaan is an accomplished instructor and an Autodesk Inventor® Certified Expert with 15 years of experience as a specialist in mechanical design primarily using Autodesk® products. He combines his expertise, knowledge, and patience to teach innovative courses in AutoCAD®, and the Autodesk Inventor Professional Series products. Christiaan has also incorporated a company, Sellier Enterprises, Inc., that specializes in mechanical design for the high speed machine-automated packaging industry.

Jim Swain Jim has 20-plus years of experience in the CAD industry, including 13 years as a product design engineer and CAD administrator. For the past 7 years, Jim has served as a senior applications engineer and trainer at Synergis Technologies, an award-winning Autodesk® Systems Center. His responsibilities include courseware development, classroom and on-site instruction and consulting, and help desk support for AutoCAD® and the Autodesk Inventor® Series. He has helped hundreds of engineering professionals at Fortune 1000 companies become more productive and efficient with Autodesk's manufacturing solutions.

Quick Spin in AutCAD® Mechanical

During this lab we will be developing a shaft for use in a belt drive lawn mower. AutoCAD Mechanical will be used to perform the following tasks:

Task 1 – Building the mower’s deck

Task 2 – Adding existing parts to the assembly using the structure catalog

Task 3 – Developing the shaft with the shaft generator

Task 4 – Bolting the assembly together with fasteners

Task 5 – Documenting the assembly

2

Quick Spin in AutCAD® Mechanical

Task 1 – Building the Mower’s Deck

Let’s take look at Mechanical’s user interface. We will be using some common AutoCAD commands and their Mechanical counterparts to draw a portion of the lawn mower.

In order to have faster access to the typical Draw and Modify commands we will dock the AM:Draw and AM:Modify toolbars underneath the AM:Main toolbar.

1. Click on the buttons shown below to launch both toolbars and dock them as shown below.

2. Click on the Basic Layer button to make AM_0 layer current.

3. Draw a line approximately 8 inches long. Next, offset this line by 0.25. This is the beginnings of our mower deck.

4. Use the Through Holes button (shown below) to insert a front view of the opening in the mower deck and choose “User Defined Hole”.

3

Quick Spin in AutCAD® Mechanical

Choose the front view option, with the midpoint of the top line as the insertion point and the midpoint of the bottom line as the length of the hole. Enter “2” as the nominal diameter of the hole. Our geometry should look like the figure below.

We now need to create some break lines for our mower deck.

5. Zoom in on the left end of the horizontal lines and start the Break Out Line command.

6. Start at the endpoint of the top line. Create a “Z” pattern ending on the point of the bottom line as shown below. When you right click to finish the break out line notice the transformation into a smooth spline with the same endpoints.

7. Start the mirror command and mirror the break out line to the other side of the deck.

8. Hatch the areas shown below. When you start Mechanical’s hatch command, pick the break out line as a boundary for the hatch, then pick the inside area to be hatched. Repeat steps for the other side of the mower deck. When you finish your deck should look like the figure below.

4

Quick Spin in AutCAD® Mechanical

Task 2– Adding Existing Parts to the Assembly

Note: A huge benefit in using Mechanical is making use of the structure capabilities. We haven’t been concerned with any structure yet because the mower’s deck plate isn’t part of the shaft subassembly that we are designing. In remainder of the exercise we will be adding existing components to this assembly and designing a new one in place. Adding components to this assembly will automatically enable Mechanical’s structure.

1. Display the Structure Catalog by selecting the Insert pulldown menu and choosing Structure Catalog.

2. From the Structure Catalog choose Housing, then drag and drop the Section view into the assembly.

3. Manipulate the section view so that it is centered over the hole, resting on the top of the plate. Make sure that the status bar is showing “TOP-DN”, so that a single pick selects the entire view. When you finish your deck should look like the figure below.

Note: You can edit the deck’s hatch pattern to distinguish it from the housing. This can be accomplished by double clicking on the pattern and adjusting the angle to your liking. You will have to re-select the break out lines, since Mechanical allows you to redefine the boundary of an existing hatch.

5

Quick Spin in AutCAD® Mechanical

4. Use the Structure Catalog to insert the section views of the Pulley and Flange.

5. Rotate and position the parts as shown below. The top of the Pulley’s hub should be 1.00” above the top of the Housing. The Top of the Flange should be 0.25” below the deck. Both parts must be centered about the centerline of the hole. Note, the dimensions shown are for reference only.

Task 3– Developing the Shaft

1. Start the Shaft Generator. Accept the default name, “Shaft1”, for the shaft.

A. Use the “object snap tracking” to start the shaft 1.00” above the midpoint of the top of the housing.

B. Use the midpoint of the flange’s bottom line for the end of the centerline.

C. The first segment is a cylinder 1.625” in length, with a diameter of 0.625”.

6

Quick Spin in AutCAD® Mechanical

D. The second segment is another cylinder. Select the top left corner of the flange for the length and 0.5” for the diameter. Note, the exact diameter will be adjusted when the bearing is added. Finish the shaft with another cylinder by selecting the bottom of the flanges through hole. When you finish your shaft should look like the figure below.

2. We now need to add a roller bearing to the shaft. Select on the “Shaft” button fly-out and select “Roller Bearings” (the ninth button on the fly-out). Select Radial bearings. Next, choose the roller bearings, ANSI/AFBMA 19.2 TDOCD series dual taper bearings and then choose Front View.

7

Quick Spin in AutCAD® Mechanical

A. Next, select the corner of the shaft’s second section for the insertion point.

B. Next, select on the shaft centerline below the first point (see figure below).

3. Measure the inside diameter of the Housing for the outer diameter of the bearing by selecting the arrow button as shown below. (Note, the resulting number should be 1.8504”.) Make sure the Dynamic Dragging radio button “On Inner Diameter “is also selected. Next, select the Finish button.

4. Dynamic drag the bearing’s inner diameter to get the largest inside diameter bearing possible and then click the left mouse button. Accept the default’s in the Create Hide Situation dialog box by selecting “OK”. A warning dialog box will appear, indicating that the shaft is the wrong diameter. Choose “Yes” to allow the middle section of the shaft to adjust to the size of the bearing.

8

Quick Spin in AutCAD® Mechanical

5. Next, we will use the Associative Hide (AMSHIDE) command to clean up the section view. Select the Associative Hide button.

6. Next, select the shaft as the foreground object and then Enter. Turn off the display of hidden lines.

Your section view should look like the figure below.

Task 4 – Adding the Fasteners 1. We will now add a bolt the housing to the mower deck. Use the Screw Connection button to start adding a

bolt, washers and a hole to the assembly. Once in the Screw Connection Dialog, select the Screws button. Next, select a Hex Head Bolt – UNC (Regular Thread – Inch) 7/16” -14 and choose Front View. Note: Read the tool tip to be sure you are selecting the correct fastener.

9

Quick Spin in AutCAD® Mechanical

2. Next, add a 7/16” Regular Helical split washer and a 7/16” Type A plain washer. Add a 7/16” Close Fit Hole. Verify that your Screw Connection Dialog Box looks like the figure below and select Next.

3. Next, use Object Snap Tracking to select the underside of the deck at the midpoint of the Housing hole for the start point. Select the topside of the deck directly above the first point for the end of the Hole. Select Next out of the Screw Assembly Location Dialog Box. Select the default Normal in the Screw Assembly Grip Representation and then select Finish. Choose the second selection for the Plain Washer. Drag the Hex Head Bolt to a length of 1”. Your assembly should now look like the figure below.

10

Quick Spin in AutCAD® Mechanical

Task 4 – Adding the Fasteners 1. Zoom out so that you can see the entire view, start the balloon command and choose the AutoAll option.

2. A red point marker will be displayed for each of the components. Pick all of them with a crossing window. Notice how the balloons follow the cursor. Right click to switch the balloons vertical alignment. Once the balloons have been placed, they can be rearranged using the Stretch command or grips.

3. Start the balloon command once again and choose the “Collect” option. Select the reference points for the bolt and washers. Use the “New” option to place a new leader with the balloons.

4. Start the Parts List command. Right click to accept the “Main” option. Highlight and remove the “Vendor”, “Material” and “Notes” columns and select the remove column button.

11

Quick Spin in AutCAD® Mechanical

Note, the “Renumber” option of the balloon command can be used to change the item numbers of the balloons. The changes will follow through to the parts list. The parts list can also be edited by double clicking on the parts list. The item numbers can be changed here as well.

5. Our final step is to add keyways to each end of the shaft and detail the shaft. Double click on the front view of the shaft in the browser to activate that view. Open the Structure Catalog and browse to the Shaft.dwg file. Drag and drop the 3-16 Sq Keyway-Front and 3-16 SQ Keyway-Side.

6. Right click on the other components in the browser and turn off their visibility. Next, position the keyways on the shaft as shown in the figure below. Next, use Associative Hide to change the upper keyway’s display to hidden. From the status bar Toggle the “BTM-UP” mode on and pick the lines that form the top of the shaft as the foreground objects.

12

Quick Spin in AutCAD® Mechanical

7. Toggle the “TOP-DN” back on. In the Browser, double click on the file name at the top to continue working on the entire assembly. Turn the visibility of the rest of the components back on. Note, the keyways were inserted from the folders, which don’t carry any BOM data. They were added to the view of the shaft because the view active at the time.

8. We now need to create an Annotation View of the shaft. Right click on Shaft1 in the Browser and select New > Annotation View. Accept the default name. Pick the bottom of the existing shaft as the base point and place the new view above the assembly. Accept the default rotation of 0 degrees.

9. Activate the Annotation View by expanding SHAFT1(AV) and double clicking on its name on SHAFT1(Front). Activate the Automatic Dimensioning button and select the existing centerline. Once in the Automatic Dimensioning dialog, select the Shaft / Symmetric and select OK.

10. Next, select the outer contour of the shaft and Enter. Next, dynamically drag the dimensions to the right. Finish by using the grips to position the dimensions in their final location.

Congratulations, you have completed the exercise! Enjoy the rest of AU 2004!

13