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In this lesson, you will draw a simple model plane fuselage--the "Guttersnipe." (The main part of the fuselage is made of plastic gutter downspout).

First, we'll set the Drawing Units so that the screen is 40 units wide. Then we'll set the large and small Cursor Step Sizes to .25 and .125 respectively.

Setting the Drawing Units
1. To set the Drawing Units, choose UNITS under the OPTIONS menu. You may also press the U key on the keyboard, which is the shortcut key for the Units command.

2. Set a point at the left edge of the screen and another point at the right edge of the screen. To do this, just move the cursor to the left edge of the screen with the mouse and click to set a point. Do the same thing for the right edge of the screen. The Drawing Unit dialog box will appear. Enter 40 in the THIS MEASURED DISTANCE IS: box. Click OK or press Enter.

Now ModelCAD knows how many Drawing Units are represented by a given distance on the screen. Each Drawing Unit may represent whatever unit of measurement you choose. Just remember to remain consistent with your Drawing Units. Don't use three Drawing Units to represent three inches, then use two Drawing Units to represent two feet, and expect ModelCAD to know the difference. The Drawing Units may be set to represent meters, inches, centimeters, or millimeters when you print out your drawing.

Setting the Cursor Step Size
The Cursor Step Size determines how far the cursor moves on the drawing screen when the arrow keys are used. To set the Cursor Step Size, choose the OPTIONS command from the OPTIONS menu, then click on the CURSOR tab.

In the CURSOR STEP area, click in the LARGE STEP SIZE text box with the mouse or move into it using the Tab key on the keyboard. Enter .25 for the LARGE STEP SIZE. Now move into the SMALL STEP SIZE text box by clicking in it or pressing the Tab key one more time and enter .125 for the SMALL STEP SIZE.

Note: If the Small Cursor Step Size is rounded up to .13 after you have specified .125, go to the GENERAL tab and change the COORDINATE PRECISION value to 3.

Setting the Snap Grid (optional)
Optionally, you can set the Snap Grid size to .125 using the GRID OPTIONS folder in the OPTIONS file box (just press Q and select the GRID tab. You do not need to set the Snap Grid, but it helps to position points exactly with the mouse.

Drawing a Side View of the Model
Choose the color you want from the color palette. Click on the COLOR tool in the Main Toolbox or select the COLOR TOOLBOX from the VIEW folder of the OPTIONS file box to bring up the palette if it is not already visible.

1. Begin with the engine mount, a simple rectangle from the side. Draw a box by selecting BOX command from under the DRAW menu, the Main Toolbox, or by pressing ] on the keyboard. Use the POINT XY command in the POINT menu two times. The first time you use Point XY specify the X-Y coordinates: (2,10) The second time you use Point XY set a point at (6,10.75).

Hint: Since you are going to be drawing several boxes in this part of the lesson, you may want to pick the Box tool from the Main Toolbox and double-click on it. This will “lock” the Box tool so that you will not have to select it each time.

2. Draw the fuselage, 18 inches long and 2.5 inches tall. Change the color that will be used by clicking on the new color in the Color Toolbox. Using the Point XY command, draw a box with corners at the following points: (4,10) and (22,12.5).

3. Draw the “tail boom” sticks, 18 inches long and .5 inches tall. Change the color that will be used again by clicking on the new color in the Color Toolbox. Draw a box with corners at the following points: (19,12.5) and (37,12).

4. Draw the stabilizer, a rectangle 4” long and .25” tall. Change the color again for this part. Draw a box with corners at the following points: (33.5,12.5) and (37.5,12.75).

5. Draw the elevator, a rectangle 1.25” long and .25” tall. Draw a box with corners at the following points: (37.5,12.5) and (38.75,12.75).

6. Draw the fin, a rectangle 4" long and 5.75" tall. Draw a box with corners at the following points: (33.5,12.75) and (37.5,18.5).

Hint: If you double clicked the Box tool to lock it, press the Esc key to unlock the command.

7. Draw the rudder, a rectangle with one corner missing (so the elevator can move upward). To draw this, select the LINE command from the DRAW|LINES menu (or use the V key, for vector line). Use the POINT XY command to draw the line through the following points:
Hint: Don't forget that you can use the F3 key to reselect the previous command (Point XY in this case), so you don't have to choose it from the menu every time.

Be sure to press Enter after you have set the points for a line or curve. With the Line and Curve commands, there is no limit to the number of points you can set. ModelCAD will continue letting you set points unless you press Enter to tell it you are finished. ModelCAD will then replace the rubber band line or curve with the actual entity.
8. Draw the tail wheel. Change the color for this step also. Draw a line from (33,12) to (34,11). Use the CIRCLE(CENTER, OUTSIDE) command under the DRAW|CIRCLES menu or the Main Toolbox to draw a circle with its center at (34,11) and a radius of .5”. To do this, set a point at (34,11) using the Point XY command, then select the POINT RELATIVE command under the POINT menu, type in .5 for DX or DY (but not both) and press Enter.
9. Draw the main landing gear. First, draw a line through these points:

10. Draw a circle with a center at (4.5, 6.25) and a radius of 1 for the wheel.
Your drawing should look like the one in Figure 4. Use the SAVE command in the FILE menu to save your drawing.

11. Now we'll use the Text Arc command to put “DuBro," “Dave Brown,” or “Sullivan” on the wheel you just drew (use your favorite brand, or put your own name on if you want).

Use the Zoom command to make the drawing 4 times larger. Select the ZOOM command from the VIEW menu. Enter 4 in the ZOOM FACTOR box. Set a point at or near the center of the main landing gear wheel you just drew.

Select TEXT ARC from the DRAW menu. In the TEXT: box, type in the name you want to put on the wheel. Press Enter to accept the text. Then set points for the command at the following locations:

An imaginary arc will be drawn from the first point through the second to the third point. The text will be drawn along this arc.

12. Select the ZOOM PREVIOUS command from the VIEW menu to return the drawing to its original size.

13. Now put some dimensions on your drawing. Under the DIMENSION menu, select DIMENSION. Click on the TEXT option button. Change your TEXT SIZE to .75 in the dialog box. Press Enter. This means the text in the dimensions will be .75 units (or inches) tall. This may appear a little tall when the drawing is printed, but it allows us to see it easily on the screen.

In the Dimension dialog box, you are allowed to specify whether you want the dimension to be aligned: automatically by ModelCAD (Automatic); along any diagonal (Free Form);horizontally (X); or vertically (Y). Set two points along the object being measured and a third point where the dimension text should be placed.

For example, to dimension the main part of the fuselage, click on X, then use the right mouse button (GRAVITY command) to set points at both ends of the fuselage you just drew. The precise locations of those points are (4,10) and (22,10). Then, place a third point below the fuselage for the location of the text. You can see where the dimension is going to be from the rubber band preview. Set the third point; the dimension will automatically be drawn.

Use the Dimension command to dimension the other important parts of the drawing. You may want to reduce the text size to get the dimensions to fit better. When you finish, you should have a drawing that looks like Figure 5. Then save the drawing.

14. Next, select the PRINT command under the FILE menu. Click on FIT TO PAPER to turn it off. In the SCALE box, enter .25. If you want to actually print the drawing out, click the PRINT button. If you do not have a printer connected, or if you do not want to print at this time, you can click on the PREVIEW button. The Preview screen will show you what the drawing will look like when it is printed.

Drawing a Top View of the Fuselage
Next, you will draw a top view of the fuselage from the first part of the lesson. If you have saved the side view, pick NEW from the FILE menu or press Ctrl+N to clear the screen and start a new drawing.

The origin, drawing units and cursor step size should be set the same as for the previous drawing: the Units across the screen should be set to 40; the Large Cursor Step Size should be set to .25; and the Small Cursor Step Size should be set to .125.

In this part of the lesson, try setting the first point for each line using the Point XY Command. Then set the rest of the points for the line using the arrow keys and the Insert key. Use the arrow keys to move a distance of .25 (Large Cursor Step). Press and hold the Shift key while using the arrow keys to move a distance of .125 (Small Cursor Step). Use the Insert key to set the points.

1. Draw the engine mount, which is actually a 2.5x4 piece of pine cut out to hold the engine. Draw a line through the following points:

Next, draw the main fuselage, which is a box 2.5 x 18 inches long that sits over the engine mount. The corners should be at (4,10) and (22,12.5).

2. Draw the spruce “tail boom” sticks that hold the tail on. These are attached to the outside of the fuselage and run parallel to each other toward the tail. They are bent inward to meet at the tail. To draw these, you will draw one of the sides, use the Parallel command to copy it .5” away, then Mirror those lines to make the other stick.

First, use the CURVE command in the DRAW|LINES menu to draw a curve through the following points:

Select the PARALLEL command from the LINES submenu of the DRAW menu or select it from the Main Toolbox. Set a point on the curve (it does not need to be exactly on it), then use the GRAVITY command to snap to the upper right corner of the box you just drew. You will have a duplicate of the curve .5” above the original. Draw a line at both ends of the curves, to connect the endpoints of the two curves (use the right mouse button to snap to the endpoints).

Select the boom stick by holding down the mouse button at one corner of it and dragging a box around the boom stick. Make sure to select only the stick, not the fuselage. Use the SET HANDLES command from EDIT|SELECTION. Move near the upper right corner of the fuselage and right click the mouse to snap to it. This will change the location of the Primary Handle. Press Enter.

Then, select the MIRROR command under the EDIT|SELECTION menu. Pick VERTICAL from the Mirror options. Leave the other options as they are set.

To place the point for the mirrored copy, pick the GRAVITY command from the Snap Toolbox and then set a point near the lower right corner of the fuselage. The cursor will snap to that corner, and make a mirrored copy of the boom stick below the original.

3. Draw the tail. Use the BOX command to draw boxes at the following locations for these parts:

Try using the Text and Arrow commands to label objects in the drawing, and dimension the different parts. The finished drawing should be similar to Figure 6.