Assemblies

After drawing several parts of a mechanical device, it is possible to bring them together as an assembly in Inventor and show how the parts move in relation to each other. The most important features to understand are the Constrain and Assemble tools. Constraints can force the faces of two objects to stay on the same plane or remain at a certain angle in relation to each other. They can also force parts to move at a given rate when when another part is moved. For example, a set of gears can have rotational constraints at a set ration so that when a small gear turns, a bigger gear will also turn so that the teeth will move at the same speed.

Assemblies can show people how a mechanism will move in the real world.

Creating Drawings from Parts

 Once a part is completed in Inventor, it is incredibly easy to transfer it into drawing form. Entire views can be produced with a single click, and dimensions can be placed without inputting values manually.

The image above shows half of the housing of a small blow dryer. To the left is a handle with text embossed on the top. At the center is the main compartment with a grill to allow airflow. to the right is the shaft that will direct air out. I placed an image of the part itself as a decal on the shaft.

The image below represents the same part, but it uses orthographic projection instead of a realistic isometric view. Their is a front view, a section view from the right, a section view from the bottom, and a section view from the left. The their are detailed views of the left section and the grill. It was difficult to get the section views to look right because I had to make the viewing depth so short that the curvature of the part would not be visible. It was also difficult to import the decal. I ended up placing it onto a power point slide and importing the slide.

Orthographic projections can be made much faster in inventor than AutoCAD because once the part is finished, the program knows what every view should look like.

Learning to Use Inventor

After working with AutoCAD for years, switching to Inventor was difficult. Although many of the tools and menus were familiar, there were just as many unfamiliar options. I had to learn how the new functions worked together with the tools I already understood. I had to learn how to handle 3D objects and constraints in Inventor.

The biggest difference between AutoCAD and Inventor is that all work in AutoCAD takes place on a single plane viewed from one direction, while sketches in Inventor can be made on any plane and viewed from any direction. The multiple planes of Inventor allow three dimensional objects to exist. A sidebar is necessary to organize the multiple sketches and extrusions so that the user can easily navigate their work. Three dimensional objects are most often produced by extruding sketches, the revolve, loft tool, and sweep tool can also produce three dimensional objects form sketches. Other tools like the hole tool and fillet tool can removed material from a shape. Because there are three dimensions, Inventor has more tools than AutoCAD and some of the tools shared by both programs do different things.

Another difference between AutoCAD and Inventor is that Inventor can dimensions objects after they are drawn. I can draw the approximate shape of a sketch and use three dimension tool to constrain the lines to the correct length. I can also constrain lines to be parallel or tangent to other features. Dimensions and Constraints make construction lines unnecessary in Inventor. instead of drawing two lines to position a circle, I can just draw the circle and constrain its position in relation to other features.

I enjoy creating 3D objects in Inventor, but I often find the software frustrating. It sometimes difficult to see and select the proper objects in 3D. If I make a mistake early on it is not easy to fix because many sketches may be dependent on earlier sketches, so deleting a sketch might mean I have to start over completely. If I don't do things the right way, I will run into problems later, so I need to take my time and think about the best way to move forward. In the graphic above, the plate connecting the base at the bottom to the ring at the top was difficult to draw. I knew how tall it was an how wide it was at the top of the base plate, but not at the bottom, so i had to draw it and extend it further afterwards. I initially forgot to extend it down, so there was a hole in the base right below it. I only realized my mistake when I was adding fillets to the edges and an error message displayed. Luckily, I could fix the sketch without starting over.

Once I understood the basic mechanics of the program, Inventor began to make a lot of sense. When I master the new concepts, it will be a powerful tool. Inventor can do for more than AutoCAD because 3D models actually replicate the shape of a part instead of showing profiles from single views.