Fab-in-a-Box Balsa Glider

Gather example materials:

Create an example glider and have it cut out or actively cutting out while students walk in.

This will be useful when discussing the parts of the gilder and the four forces of flight.

Welcome:

Welcome class and open discussion of what we are doing today.

Show the example of a cardboard glider and discuss the 4 forces of flight.

(Hint: Cut and assemble a balsa glider ahead of time. You will use this as a physical example when discussing the 4 forces of flight!)

Explain the Engineering Design Process.

Explain CAD (Computer Aided Design) Software

(Hint: Ask students to raise their hand if they know what photoshop is, most will. Explain that Photoshop is a photo editing design software and we will be using a vector or graphic design software)

Key terms:

Key Science Concept: Aerodynamic Forces

Four main forces keep planes in the air: thrust, lift, gravity, and drag.

1. Thrust: the force propelling a plane forward. Thrust is most often generated by fuel combustion (or your throw!). 

2. Lift: the force acting upward on a plane’s wings to keep it aloft. Lift is generated as a plane moves forward and air moves more quickly across the top of its wings than beneath them. Generally, the larger the wings, the greater the lift.

3. Gravity: the force pulling a plane’s mass down toward the ground. Lighter materials can help a plane stay airborne longer.


4. Drag: the frictional force a plane experiences from air flowing past it. Drag is the opposite of thrust, and slows a plane down. It is largely influenced by its tail design.

Which of these forces act against each other? 

Which forces are present when a plane is sitting stationary on the ground? 

What about taxiing in (rolling along) the runway?

Context:

Planes’ designs must balance all of these forces. The shapes, sizes, and materials used for the wings, body, nose, and tail can all drastically affect the way a plane flies. How can you engineer a plane to take advantage of these forces?

5. Aerodynamic: of or having a shape which reduces the drag from air moving past.

6. Fuselage: the body of a plane

7. Horizontal Stabilizer: the tail of a plane

8. Engineering Design Process:

In the Real World: Engineers don’t create perfect designs on the first try. They test, redesign, and retest their ideas again and again, making small changes each time based on their observations. This is called iterative prototyping, and it’s a key part of the engineering design process. Instead of thinking of mistakes as “failures,” think of them as rough drafts of a finished product. Each one is a step closer to success!

Intro

Design and fabricate your own custom glider. Test its flight, then optimize its performance by adjusting the shape of its wings, tail, or body or adding a nose weight.

xDesign Steps

DESIGN YOUR AIRPLANE

Click OPEN on the xDesign landing page

Click the “Minimize” icon in the upper right-hand corner of the Search results page

— the results will be repositioned to the right-hand side of your screen so you can see things alongside your xDesign session

[1] Type “Lesson10” in the Search field, [2] press Enter on the keyboard, then [3] click on the blue header bar (to dismiss the Search History panel)

— the Search results will update to show you the glider templates

[1] Drag the Airplane template into your xDesign session and then [2] click “Cancel” in the lower right-hand corner of the Search results panel

Click SAVE AS… in the dialog that appears

[1] Type a new name for the component (perhaps add your initials) and then [2] click SAVE

Select the YZ plane and then click the “Create a sketch” command

Click the “Line” tool on the Action Bar

Click [1] to snap the first point of your line to the “Layout” sketch, and then click [2] to draw a horizontal line. Move your mouse to up and to the right, then click [3] to draw a slanted line that will become the tail of the fuselage. While staying inside the largest rectangle of the “Layout” sketch, continue clicking to draw lines in the shape of fuselage you’ve imagined. End your chain of lines at [1] where you started.

— sample fuselage —

Use 4 lines, or the rectangle tool on the Action Bar, to draw a rectangular opening for the wings

Click the “Sketch Dimension” tool on the Action Bar

Add whatever dimensions you’d like to fully define your sketch.

— sample dimension scheme —

Work with your instructor to measure the thickness of the wood you’ll laser cut and then enter it as the height of the wing and tail slots. 

TIP: factor in a small amount of interference so the wings and stabilizer will fit snugly

Click the “Features” tab on the Action Bar and then click “Extrude”

Set the Direction 1 end condition to Midplane and the Distance to match the thickness of material you are using.

Repeat the above steps two times to design the wings and horizontal stabilizer.  Each time…

Start a new sketch on the YZ plane

Draw and dimension the wing or stabilizer

Extrude midplane with the proper thickness 

Sample Wings

Sample Stabilizer

The xDesign Design Manager will now look something like this:

ASSEMBLE YOUR AIRPLANE

Select the extrude feature in the Design Manager that created the fuselage and then click the “Make Component” command from the context menu.

Type a unique name for your fuselage and then click the green checkmark.

Repeat the above steps two times to transform the features for the wings and stabilizer into components. Each time…

Select the extrude feature that created the wings or the stabilizer

Click Make Component

Give it a unique name and click the green checkmark

The resulting Design Manager will look like this:

Hold down the Ctrl key and select the wings and stabilizer components. Then select “Fix Component” from the context menu.

All three components will now be fixed in place.

Hold down the Ctrl key and drag the large face of the fuselage to create a copy of it

Select the newly created fuselage copy in the Design Manager and then click “Fix Component” in the context menu.

Hold down the Ctrl key and drag the large face of the wing to create a copy of it, and then hold down the Ctrl key and drag the large face of the stabilizer to create a copy of it too

Reposition the wings or stabilizer by dragging them on screen. Hold down ALT while dragging and the component will rotate.

Select two faces to mate to one another and then click “Coincident” from the quick mate toolbar

Repeat this process to add another coincident mate that holds the bottom of the wings to the bottom of the fuselage slot

Expand the Fuselage component in the Design Manager and select the YZ plane

Click the Assembly tab of the Action Bar and then click the “Symmetry” command

Select the two outermost edges of the airplane wings and then click the green checkmark.

Repeat this process to assemble the stabilizer.

Add two coincident mates to position the stabilizer in the tail slot

Add a symmetry mate to center the stabilizer

Your finished plane will look something like this:

Saving

Naming recommendation – “Student Name Project Version#: Joe A Glider v1.dxf”

Remind students of the Engineering Design Process and explain that we do not want to save over past designs. Every new design will be numbered to show what version they are on.

(Hint: This is very helpful when cutting on the laser and will allow you to keep track of how many versions are created)

Laser Cutter Safety Note: Never leave the laser unattended! Laser cutters use high-powered beams that can ignite flammable materials like wood, paper, and plastic, even if the metal being cut doesn’t ignite. Slag from cutting metal can also start fires if flammable materials are nearby. If the laser cutter is being supervised, a CO2 fire extinguisher can usually put out a fire quickly.

(Students should be encouraged to run the machine with instructor supervision!)

Laser Cut Fuselage (body)

Connect laser cutter:

Turn the laser cutter on and connect it to your computer via USB.

Open xTool’s XCS software (download here).

Select “connect device” in the upper righthand corner of XCS.

Choose your laser cutter from the pop-up menu.

Import design file:

Click the file folder icon in the upper lefthand corner. From the dropdown menu, select “import image.” Choose your file.

Select the circular handle to rotate your design as needed to fit onto your stock. 

Note: do not resize within XCS! Remember: your design is parametric, and the slots are perfectly calibrated for the width of your stock material. If you resize outside of your CAD environment, the slots will also change.

Configure cut settings:

Select “user-defined material” from the dropdown materials list.

Combine all elements (lines) you want to cut on a single layer. 

To add or switch layers, click “move to.”

Select “cut” under the “processing type” menu.

Check settings

For 1/16” balsa wood, we suggest the following (power/speed/pass):

Score: 40/150/1

Engrave (raster): 30/200/1

Cut: 100/15/1

Note: the machine will automatically score and engrave before it cuts, and cut inside elements before outside elements. 

Prepare laser cutter:

Open the laser cutter lid and place stock (balsa) onto the honeycomb. 

Manually drag the laser head over the center of the stock.

Close the lid.

Click “auto focus” and wait for the machine to focus. 

Open the lid. Manually drag the laser head to the top left corner of the desired cutting area.

To check framing, click “framing” in XCS and then press the button on the machine. The laser head will frame the area to be cut. If it does not fit on the stock or overlaps a previous cut, adjust the starting position as needed.

Run the job:

Click “process” in XCS, followed by the button on the machine.

Remove pieces:

Check to make sure all pieces are cut through, and rerun (adjusting settings as necessary) if not. 

Remove workpieces and scrap stock from the machine bed.

Close the lid.

Vinyl Cutter Safety Note: Operation of this device requires use of sharp blades and caution should be taken to make sure that fingers do not get caught in moving gears during operation.

(Students should be encouraged to run the machine with instructor supervision!)

Vinyl Cut Wings & Tail

Prepare the machine: 

To turn the machine on, long-press the power button on its right side for 2-3 seconds.

Open the machine’s hood.

On the tool carriage, pull the locking mechanism completely out.

Place the autoblade into the tool slot, and make sure it is fully inserted.

Push the locking mechanism back into place.

Prepare the cardstock:

Use a light hold cutting mat (or one where most of its “sticky” has worn off.”

Position your cardstock on the paper.

Load prepared cutting mat into the machine.

Configure cut settings:

In the silhouette software, turn on “line segment overcut.”

Run job:

Click “send.”

Remove your pieces:

Don’t peel the paper off the cutting mat! Instead, turn the whole thing upside down and peel the cutting mat off the paper instead.

Assemble

Insert wings through the slot in the plane’s fuselage (body). Make sure they’re centered; the notch will help keep them in place.

Slot your horizontal stabilizer (tail) into place.

Optional: add a paperclip nose weight! (Tape and pennies also work).

(Hint: If time allows, have students create vinyl sticker decals to decorate their gliders.)

Test and Evaluate

Stand in the same spot and attempt to apply the same force for each launch.

(Hint: This is best done in a hallway or gym. Using a line of tape on the ground will help students with throwing from the same spot)

Measure and record the glider’s distance traveled after each flight.

Optional math tie-in: launch at least three times and calculate the average distance traveled.

Redesign and Try Again

Adjust your design files and try again. 

(Hint: this works best if you adjust only one part at a time!)

Discussion Questions:

How did the four forces of flight impact your design?

How did the changes you made influence the distance of your glider’s flight?

Based on your observations, what changes could you make to further improve upon your design?

What would you have done differently from the start?

Optional: have students present their projects in a “mock round table” discussion. This can benefit students in their understanding of peers’ design process and how to lift one another up.

Optional Tie-ins:

Historical Figures in Aviation:

Wright Brothers: Discuss the pioneering work of Orville and Wilbur Wright in developing the first successful powered airplane. Highlight their use of engineering principles and experimentation, which can inspire students as they design and test their own gliders.

Amelia Earhart: Explore the achievements of Amelia Earhart, the first woman to fly solo across the Atlantic Ocean. Her story can motivate students to pursue their own aviation-related projects and careers, emphasizing the importance of perseverance and innovation.

Howard Hughes: Examine the contributions of Howard Hughes to aviation and aerospace engineering. His work on advanced aircraft designs and record-breaking flights can provide context for the engineering challenges and opportunities in aviation.

Charles A. Lindbergh: Discuss Charles Lindbergh’s historic solo nonstop flight across the Atlantic Ocean. His achievements can serve as a case study in the importance of aerodynamics, endurance, and the human spirit in aviation.

Career Connections:

Aerospace Engineer: Highlight the role of aerospace engineers in designing and testing aircraft, spacecraft, and related systems. Discuss how the skills learned in designing and building balsa gliders can be foundational for a career in aerospace engineering.

Aviation Specialist: Explore the various careers within the aviation industry, including pilots, air traffic controllers, and maintenance technicians. Emphasize how understanding the principles of flight and aerodynamics is crucial for these roles.