Show Me - Free Body Editor

It is essential that all FBD files be contained in a common folder (called projects in this example). Each project is a combination of a project file (created by the editor when you save the project) and an image file. It is important that the image file have a specific name of the format:

• project file: filename

• project image file folder: filename_images

Notice, for example that project_1 is accompanied by the folder project_1_images. You can assign any valid name you wish to the project file but you must also store all images for that project in an appropriately named folder.

For Example...

You have created a project called myproject1. All of the images that you use for this project must be in a folder called myproject1_images and this folder must be on the same level as the project file myproject1.

1. We are going to create two projects called myproject1 and myproject2. These projects will be stored as individual files within the projects folder. Before you start, however, you need to create two image folders called myproject1_images and myproject2_images. Look at the file structure shown on the right and compare it with the file structure from the previous section.

2. Next, place two image files in each of the folders that you just created. Either copy or move the files fig1.jpg and fig2.jpg into myproject1_images and fig3.jpg and fig4.jpg into myproject2_images. You may create your own files or use the files that are contained in the root of the projects folder.

3. You are now ready to create the project files. To do this, press the "File" item on the upper left corner of the applet and select "New Project" as shown on the right. Alternately, if you have just opened the applet and there are no previous projects loaded you can begin to load images immediately by pressing the "add FBD" button () in the FBD editing panel.

4. Press "add FBD" () and follow the directory that opens until you come to the folder myproject1_images. Open this folder and select fig1.jpg. You should see something similar to the menu shown on the right.

5. On the left hand side of the applet you should see the label "fig1" appear in the FBD Description field as well as in the FBDs in project list as shown on the right. The image will load in the FBD Drawing Area.
6. The default description is always just the file name. You may wish to give this a more informative name. Simply type this information in the FBD Description field. This information will update in the FBDs in project list and will be saved when you create the project. Practice this to see how you could use this feature.
7. Repeat the steps from #4-6 and add fig2.jpg to your project.

8. You are now ready to create your project! The "FBDs in project" list should contain two entries at this point. Now, simply open the file menu in the upper left corner of the applet and select "Save Project" (). You should save the project as myproject1 (no extension) HOWEVER - before doing this make sure that you are saving the file in the proper location. You will most likely be within an image folder at this point so you will need to go back one level and save you project file there. This is shown on the right.
9. Congratulations! You have created a project. Now repeat these steps and create the project myproject2 and include the files fig3.jpg and fig4.jpg. In the next section we will look at how to edit these files to create usable FBD's.

1. Load project "mproject1" by choosing ) and choose the image shown on the right (You can choose any other image if you wish - this is just for illustrative purposes.)
2. Under "FBD Description" you may choose to change or edit the text description of this applet. Simply type an appropriate descriptor here.
   
3. The drawing panel is now active and you can use the mouse to draw anywhere on this image. The applet is, by default, in the draw new vectors mode (). To create a vector simply position the mouse where you wish to begin the vector ("tail of the vector") and then press the left-mouse-button and drag in the direction and to the length you wish.

3. As an example, try drawing in a vector that will be used to represent the weight of the coin. Position the mouse near the center of the coin and drag straight down. You should see something similar to the figure on the right.
4. If you are "happy" with this vector you can continue and draw more vectors if appropriate. How to edit the vector you just made is discussed in the next section.
5. Let's assume that you are happy with the vector just made but would like to give it a better label than "vector 1". To do this first note that in the "selected vectors" panel on the right vector 1 is highlighted (its also the only vector there so far). This means that vector 1 is "selected" and you can modify its name simply by typing the name you want to use in the space under "Selected Vector Name" . Type in Weight or any other name you think is appropriate.

6. The figure on the right shows the Free Body Diagram with the remaining two forces drawn in. Try to duplicate this. If you forget to type in the name of one of the vectors, take a look at the next section to see how to edit vectors.

1. Once you have constructed a free body diagram you may wish to alter it. You can:
   • reposition the vectors to make them easier to see (some people even argue that the correct way to draw a FBD is to draw the forces from a point that is NOT drawn on the body itself)
   • change the length or direction of a vector
   • change the colour of the vector to make it more legible
   • rename a vector
2. As an example let's modify the FBD that you made in the previous section. In particular we will want to move the vectors to make them more legible, and change their colours.

3. Let's start by selecting the vectors. To do this, click on the current name of the vector. This makes that vector "active" and allows you to then edit it. For example, let's reposition the inward force vector. So, first select Inward Force (see figure on the right).

4. Next, press the "set vector origin(s)" button (). You may now drag this vector to any location you wish. Do the same for the remaining two vectors. For example, move the FBD to the white space below the image. You should see something similar to the diagram on the right.
5. At this stage you may wish to change the colour of each vector. Both the Weight and Normal Force vectors are OK but the Inward force vector is illegible. Change its colour to red.
6. To do this you will need to once again select the vector that you want to change and then press the color icon (). This opens the colour editing panel. Simply click on the colour that you want and then press "OK" to close the colour dialogue. The vector and its label will now appear in the newly selected colour.

7. Finish creating and editing the other FBD's in your project and then save the project by selecting from the file menu choices.

3. This is what the param tag looks like

4. In order to make your new projects (myproject1 and myproject2) visible to the applet you will need to replace the string " FBD,project_1,project_2" with either an augmented of otherwise modified version of this.

5. For example, to add the projects "myproject1 and myproject2" , the parameter would now look like what is shown on the right . When you run Free Body Drawer and select a project, you will see five projects listed.
6. The easiest way to change this is to use either NotePad or an HTML editor and do a search and replace on all instances of the string "FBD,project_1,project_2". This occurs twice in the HTML file.

7. BE EXTREMELY CAREFUL editing this file! You are strongly encouraged to first save a backup version of this file. When you have completed these changes save the file actionreaction.html and upload this (if necessary) to your server and replace the old version of this file.