Introduction to Revit

Objective

This exercise will introduce Autodesk Fusion 360, which is a drafting software that is used by technical professionals, and basic technical design methods will be shown using this computer-aided design (CAD) software. This software will be used in the semester-long design project (SLDP) by constructing physical prototypes with 3D printing. To practice this prototyping procedure, an NYU logo keychain will be created in Autodesk Fusion 360 and prepared in Cura to be 3D printed.

Overview

Computer-Aided Design

CAD programs, which include Autodesk's Fusion 360, AutoCAD, and Revit; Dassault Systèmes SolidWorks; and Google SketchUp, allow engineers to make dimensioned, scaled drawings. These drawings are used to manufacture equipment, build infrastructure, and allow designers to display their designs with complete specifications and detail. Orthographic views (top, bottom, side, front, back) can be used to document the technical specifications in drawings needed for production while axonometric views (isometric, dimetric, trimetric) can be used to view the final 3D representation of a product.

This exercise will teach the basics of Autodesk Fusion 360, 3D file formats, the basics of 3D printing, and the skills needed to create simple 3D files and prepare them to be 3D printed.

3D Printing

3D printing allows rapid prototyping and onsite manufacturing of products. Initially done with plastic, 3D printing now uses new techniques with new materials, such as aluminum, bronze, and glass. Biomaterials are also being used, such as 3D printing ear cartilage and liver tissue. As the 3D printing industry grows, 3D printing has become a significant part of many engineering fields.

In this course, 3D printing can be used to produce prototype components, building models, SLDP course modifications, robot parts, and a company logo.

Procedure

1. Setting up the File

1. Launch AutoDesk Fusion 360, click Create Account, and fill in the information. Important: Make sure to use an NYU email (Figure 1).

Figure 1: Fusion 360 New File Options

2. Designing the NYU Keychain

1. First, ensure that the units of your drawing are in inches. They are in the Browser on the left side of the window under "Document Settings".
2. Start a 2D Sketch by clicking "Create Sketch" (Figure 2).
   

   Figure 2: Sketch Mode
3. Select the XZ plane (Figure 3).
   

   Figure 3: XZ Plane
4. Select the 2-Point Rectangle from the "Sketch" section of the toolbar (Figure 4).
   

   Figure 4: 2-Point Rectangle
5. Draw a 2.6” × 0.7” rectangle starting at the origin. Click once at the origin to place one point of the rectangle and click one more time to place the second point of the rectangle. The length values can be typed in before placing the second point of the rectangle (switching which value is changed is done using the Tab key).
6. Select the Center Diameter Circle from the "Sketch" section of the toolbar.
7. Draw a 0.7” diameter circle centered in the middle of one of the 0.7" sides of the rectangle (the cursor should become a blue X with a triangle and snap to the midpoint of the line when you get close) (Figure 5). Similar to the 2-Point Rectangle, the diameter of the circle can by typed.
   

   Figure 5: Center Diameter Circle
8. Draw another circle 0.45” in diameter in the same position. The sketch should look like Figure 6.
   

   Figure 6: Circles of Keychain Base
9. Fillet (round) the corners of the base. Select the Fillet tool from the "Modify" section of the toolbar (Figure 7).
   

   Figure 7: Fillet Tool
10. Select one of the two intersecting lines that form the right angles on the base. Set the fillet radius to 0.125" and repeat on the other corner. The sketch should look like Figure 8.
    

    Figure 8: Filleted Corners
11. Remove the extra lines using the trim tool. Select the trim tool from the “Modify” section of the toolbar.
    

    Figure 8: Trim Tool
12. Select all interior lines that divide the keychain to trim them. If error messages are indicated, remove the dimensions on the rest of the keychain by clicking on them and pressing the Delete key. The sketch should look like Figure 9.
    

    Figure 9: Keychain Base
13. Exit the sketch using the "Finish Sketch" button in the top right of the window.
14. After creating a 2D sketch, the next step is to use that sketch to create a 3D object. The Extrude tool will be used to create a 3D block. In the future, the Revolve or other tools can be used to create more advanced geometry. Select the “Extrude” tool from the “Create” section of the toolbar (Figure 10).

Figure 10: Extrude Tool
15. The Extrude information dialog will pop-up on the right side of the window. First, select the profile of the object to be extruded, which is the sketch that was just created. The sketch will highlight blue if it was made correctly. Click and change the extrusion thickness to 0.15" and press the Enter key. Click OK in the Extrude information dialog. The model will look like Figure 11.
    

    Figure 11: Extruded Sketch
16. The next step is to add the design to the keychain. A vector graphics file will be used in the DXF format provided by NYU. In the future, a logo can be designed using the sketch tool. Download the Tandon Logo DXF File (this logo was converted from the file provided on NYU's identity page).
17. The downloaded ZIP folder must first be extracted. Then, select "Insert DXF" under the "Insert" section of the toolbar (Figure 12).
    

    Figure 12: Insert DXF Tool
18. The Insert DXF information dialog will appear on the right side of the window. For the Plane/Sketch, select the top surface of the keychain (Figure 13).
    

    Figure 13: Selected Top Surface
19. Click the folder icon next to "Select DXF file" to upload the Tandon Logo DXF File. The logo should appear (Figure 14)
    

    Figure 14: Imported DXF Logo
20. Change the units to inches and click OK.
21. The vertical bar and "Tandon School of Engineering" portions of the logo are not needed. Select the bar and text to the right by clicking and dragging (Figure 15).
    

    Figure 15: Tandon to Delete
22. Delete this portion with the Delete key on the keyboard (not Backspace).
23. The logo needs to be scaled to fit the keychain. A base point must be selected for which the sketch will be scaled to. The midpoint of the line on the right side of the box around the torch will be used as the base point, so a point must be placed there first.
24. To place a point, the sketch must be in editing mode. A sketch is known to be in editing mode when the background turns into gridlines and “Finish Sketch” appears at the top right of the window. Enter the tandon_long_white sketch by double clicking on the sketch name in the Browser.
    

    Figure 16: Sketches in Browser
25. Select the Point tool under the "Sketch" section of the toolbar. Place a point at the midpoint of the right side of the box around the torch (Figure 17).
    

    Figure 17: Midpoint on Box
26. Delete the bottom and the left side of the box around the torch. (Figure 18)
    

    Figure 18: Partly Deleted Box
27. Select the Sketch Scale tool from the "Modify" section of the toolbar. The Sketch Scale information dialog will appear on the right side of the window. For the Entities, select the remaining lines of the box and torch of the logo by clicking and dragging. Make sure to not select the midpoint that was just placed on the right side of the box .
28. Select the midpoint that was just placed as the Point for scaling.
29. Enter a scaling factor of 0.75 and click OK. (Figure 19)
    

    Figure 19: Scaled Box
30. Redraw the two sides of the box that were deleted using the Line tool in the “Create” section of the toolbar (Figure 20).
    

    Figure 20: Redrawn Box
31. The logo must now be positioned on the keychain. This will be done by drawing a line for alignment and moving the logo design to where the alignment line is located. Select the line tool and draw a 0.925" horizontal line from a point close to the center of the hole in the keychain base to the right (Figure 21).
    

    Figure 21: Alignment Line
32. Select the entire logo by clicking and dragging. Then select Move/Copy under the "Modify" section of the toolbar.
33. The Move/Copy information dialog will appear on the right side of the window. The Selection should already be made (the NYU logo). Select “Point to Point” as the Move Type. For the Origin Point, select the midpoint from the side of the box around the torch. For the Target Point, select the right end of the alignment line that was previously drawn (Figure 22). Click OK.
    

    Figure 22: Move/Copy Tool
34. Delete the alignment line that was previously drawn.
35. Click "Finish Sketch" in the top right of the window to exit the sketch. The final sketch is shown in Figure 23.
    

    Figure 23: Final Sketch
36. To finish this side of the keychain, the design must be cut into the base. To do this, the extrude tool will be used.

    1. 1. To cut the design, select “Extrude" from the "Create" section of the toolbar.
       2. Select the profile of the design to cut, in this case, the area around the torch and each of the letters. (Figure 23)
          

          Figure 23: Select the Outline
       3. Select "Cut" from the drop down menu next to "Operation" in the window that appeared on the right. (Figure 24)
          

          Figure 24: Cut the Outline
       4. Select a distance of -0.06".
       5. The final model is shown in Figure 25.
          

          Figure 25: Depth to the Outline

37. To 3D print the design, export the file as an STL. This is the only format that can be opened by the 3d printing software.

    1. Click on triangle to the left "Document Settings" to expand the menu, and hover over "Units" to click on the "Change Active Units" button on the right to change to millimeters, but DO NOT set millimeters as the default (default units should be inches). This will convert the model into millimeters. Even though the models are built in inches, millimeters is the only unit that 3D printing software will recognize.
    2. Right click on the box above “Document Settings” and select “Save as STL”. (Figure 26)
       

       Figure 26: Save Your Work
    3. Click "OK" no need to change any of the setting.
    4. Make sure you save it to a location you'll remember like the desktop.

38. The last step of the keychain is to make the white insert that will fit in the center to make it two colors.

    1. Click “File" in the toolbar at the top of the screen.
    2. Start a "New Design". (Figure 27)
       

       Figure 27: New Design
    3. Create a rectangle with dimensions 2.2”x0.65”.
    4. Extrude the rectangle 0.12”.

       1. This model is shown in Figure 28.
          

          Figure 28: Inside Box

    5. Save this the same way as before.

Preparing to print

1. Now that the logo design is complete, the next step is to put it together in the 3D printing slicer software. We will be using Cura as the software for orienting parts on the printer and selecting the color of each object. It also generates toolpaths that the printer will follow to print the objects.

   1. Open Cura. If a menu pops up prompting for the printer, select the “Ultimaker 3”

      1. If a menu does not pop up, make sure the printer currently selected is “Ultimaker 3” on the top right corner
      2. Otherwise, click the arrow, select the “Add Printer” option, and add “Ultimaker 3.”

   2. To load your two files from above, select “Open File” on the top left corner and open the STL file containing the base of the keychain
   3. Using the “Rotate” tool on among the options to the left, rotate the part so the torch is facing up

      1. Uncheck the “Snap Scaling” option to allow for a more precise rotation

   4. Select “Open File” again and load the filler rectangle
   5. Again, orient the part correctly using the “Rotate” tool
   6. Cura, by default, drops the objects on to the build-plate and keeps objects apart. The following steps are needed to combine the filler rectangle within the keychain:

      1. Under “Preferences”, select “Configure Cura”
      2. Under “Viewport behavior,” make sure to deselect both “Ensure models are kept apart” and “Automatically drop models to the build plate” if they are not already deselected
      3. Save your preferences
      4. Return to the buildplate and make sure both objects are lying flat on the build-plate by using “Rotate” => “Lay Flat”

         1. If the “Lay Flat” tool does not lay the object flat, manually type in 0 mm in the “Move” tool for the Z axis

   7. Select the filler rectangle, and using the “Move” tool on the left, enter 0.15mm as the Z value to raise it vertically
   8. Select one object and choose a different extruder on the left. That piece will appear as a different color
   9. Drag the filler piece and place it in the keychain base part
   10. Export the file as a .gcode and upload it to the website

Figure 29: Cura with both parts loaded

Figure 30: Cura with the base and the infill of the logo

Assignment

A *.gcode file must be submitted to eg.poly.edu. It is required for a lab report grade.