Robotic Arm After School STEM Academy Student Journal
Vocabulary Compression: A pushing, squeezing force. Friction: A force that resists motion. Fulcrum: The point at which two things pivot or swivel. Lever: A rigid bar attached to a pivot used to transmit force. It converts a little effort into a lot of force. Tension: A pulling, stretching force.
Activity One Design a String Puppet Materials Each group of 3-4 students will need: 2 narrow straws 1 wide straw Fishing line Scissors Tape For the group: Extra straws Single hole-punch Foam pieces, for puppet creation Markers Method 1. Notch the straws Use scissors or a single-hole punch to cut notches in the side of a narrow straw. These are the straw s joints. Experiment! Where you cut the notches will change the way the straw moves. Cut notches on the same side of one straw. With the second narrow straw, notch on different sides. TIPS: o If you want your arms to bend in one direction Make sure your notches are along the same side of the straw. o If you want your arms to bend in different directions Alternate the notches on either side of the straw. o If your joints don t bend easily Cut a deeper notch (but not too deep!). There needs to be some rigidity for the straw to go back to its normal shape when you let go of the string. 2. Thread the string Cut a piece of fishing line three times the length of a straw. Thread it through one of the narrow straws. 3. Tape the string When the string pokes through the end of the straw, bend it over the tip and tape it. Leave the other end loose. Cut another piece of fishing line and thread it through the second narrow straw. Tape it as you did with the first. 4. Make it move Adapted from PBS Design Squad Nation: pbskids.org/designsquadnation
Activity One Design a String Puppet Pull the loose strings. Watch your straws bend. What ideas does this give you? What type of puppet will you make? 5. Feed the strings Pull the loose strings of both narrow straws into and through the wider straw. 6. Wedge the straws Wedge the ends of both of the narrow straws into the wider straw, far enough down that they are secure. Both strings should now hang out of the bottom of the wider straw. TIP: If you wedge the narrow straws too tightly into the wider straw Back them out a bit. The string needs to be able to slide easily without catching or rubbing. 7. Tape the ends To pull both strings easily, tape them together and make a tab that lets you pull the two ends of string together. 8. Give it a tug Pull the tab and watch both arms (or maybe they are legs ) of your puppet move 9. Get creative! Each group can create their own puppet of a design that they choose. Encourage groups to discuss the puppet they would like to make. These could serve as a team mascot in the coming weeks, if teams are interested. Decorate the puppets! Add a head, body, and eyestalks, arms, and legs. Adapted from PBS Design Squad Nation: pbskids.org/designsquadnation
Activity One Design a String Puppet Reflection Draw a picture of your String Puppet below: What worked well? What would you do differently next time? Adapted from PBS Design Squad Nation: pbskids.org/designsquadnation
Activity Two Engineer a Helping Hand Materials Each group of 3-4 students will need: 4 brass fasteners 2 cardboard pieces 2 rubber bands Scissors Tape 4 wooden skewers 4 toothpicks Paint stirrer For the group: Single hole-punch Sandpaper String Design Sketch your design for your Helping Hand below. Remember, it needs to grab, not scoop!
Activity Three Helping Hand: Lifting Materials Each group of 3-4 students will need: Helping Hand from last week Tennis Ball Paper Cup Reflection Which challenge was easiest for your group s Helping Hand? Which challenge was hardest for your group s Helping Hand? What else would you like to try with your Helping Hand?
Activity Four Heavy Lifting Introduction This week s challenge is about living on the moon which gets expensive fast. Shipping things from Earth costs about $25,000 a pound! No wonder NASA plans to use materials found on the moon, such as calcium compounds to make cement and nitrogen compounds to fertilize crops. To mine materials like these, astronauts use cranes for digging and moving heavy or bulky loads. You are challenged this week to design and build a crane, and see how heavy a load it can lift. Materials Each group of 3-4 students will need: Cardboard box Cardboard sheet, 8.5 x11 Paper clip Paper cup 3 sharpened pencils Scissors Fishing line Tape hook arm For the group: Weights (hex nuts or washers) take-up reel
Activity Four Heavy Lifting Design Plan your crane below: Test How many weights could your crane hold? How many could the strongest crane in the class hold? Reflection What would you improve about your crane if you were to build it again?
Activity Five Robotic Arm Introduction Students will design and construct a robotic arm that can lift a cup off a table. When would you use a robotic arm? Scientists at NASA use them frequently! To explore the surface of a planet, moon, or asteroid, rovers use robotic mechanical arms to do such things as collect samples, take pictures, and monitor the environment. Robotic and human arms have similarities. Both use flexible parts (string or muscle) to move rigid parts (cardboard or bone). The string or muscle s pull is directed by a guide (straw or tendons), and the guide s position affects the arm s efficiency. Finally, the brass fasteners mirror our joints. Make the strings (tendons) in the hand visible by having kids lift their fingers up and back. Materials Each group of 3-4 students will need: Cardboard strip that is 2x8 inches, hole punched in the corner Cardboard strip that is 2x4 inches, hole punched in the corner Brass fastener Straw, cut into 1-inch lengths Fishing line 2 jumbo paper clips 2 paper cups, 3 oz Tape For the group: Single Hole-punch
Activity Five Robotic Arm Design Draw a picture of your robotic arm below: Reflection What worked well for your robotic arm? What could be improved if you were to redesign it?
Activity Six Robotic Arm with Helping Hand Challenge Introduction Students will use the items they have built to complete a series of challenges. Students will add a hook to the Robo Arm, and will also use their Helping Hand Materials Each group of 3-4 students will need: Robo Arm from previous session 2 paper clips Tape Helping Hand from previous session Tennis Ball Paper Cup Example: Robo Arm with Hook Method 1. Add a hook to the Robo Arm Unbend paper clips to form hooks and poke them into one of the arm s corrugation tubes. The, tape a second paper clip hook to a cup. Use the paper clip hook to try to hook the target cup. 2. Play games with the Robo Arm!
Activity Six Robotic Arm with Helping Hand Challenge Reflection What was your favorite thing to build this session? Why? What would you like to design and build next?