Ultimate Science Curriculum

Lesson #27: Two-Wheeler Robot

If you've ever ridden a two-wheel bicycle, you know that you have to not only pedal to move forward, but also balance in order to stay upright while you move.

Two wheeler robots are difficult to make because they need to balance in addition to carry out commands. The balance is done autonomously, meaning that the robot must be programmed to figure out how to balance itself.

We're going to skip this complicated step and instead use gravity to balance for us. While this makes the robot a lot smaller, it's also a lot quicker and easier to build than the model in this image. Are you ready?

Materials:

• 2 old CDs
• popsicle stick
• two tops from water bottles
• 2 battery packs that hold 2 AA batteries each
• four AA batteries
• two 3V motors
• 4 alligator clip leads
• drill with drill bits
• hot glue gun

Lesson #28: Amphibious Robot Vehicle with Transmission

The image here is the 2003 Gibbs Aqauda at full speed in deep water! It looks like it's just skipping along the surface, doesn't it?

The Gibbs company uses auto, marine, and propulsion technologies to build water-land vehicles used mostly by the military. But wouldn't it save time to cut through the traffic on the bridge if you could skim through the water?

One of the main issues with amphibious vehicles is that they are painfully slow - both in the water and on land. (Although the 2003 Aquada gets up to 30 mph in water.)

The other issue is safety - the lift from the bow on a boat is needed to avoid plunging, but on a car you don't want the front end to lift at high speeds.  Also a boat distributes the load evenly across the hull while a car has  concentrated loads where the suspension is attached to the frame.

The Aquada car uses a 160 hp engine for land and a compact jet that produces 2,000 pounds of thrust. It broke the record for crossing the English Channel by four whole hours (third image below with the orange boat in the background).

And if the car goes fast enough, you can pull a waterskier.

The Gibbs company has also invented the Humdinga, which is for military use, as it has four-wheel drive at can cruise at 40 mph on water, as well as the Quadski, which travels at 50 mph on land or sea.

We're going to build our own model, though not with a jet engine. We're going to use a motor, wheels, floats, and wires to build a real working model you can use in the tub tonight. Our model is also going to have a transmission that will enable you to get  two different speeds using very simple materials. Are you ready? Here's what you need to do:

Materials:

• four popsicle sticks
• 2 AA batteries in a case
• rubber bands
• 2 wheels from milk jug lids or film canisters
• one 1.5-3VDC motor
• two alligator wires
• three water bottles
• straw
• two wooden skewers
• scissors
• hot glue gun with glue sticks
• drill with drill bits

Lesson #29: Grinder Gearworks

Have you tried sticking a plastic wheel straight onto a motor shaft to create a race car? The first thing you'll find is that the shaft is usually so slick that it doesn't stay attached to the wheel without a ton of glue. And IF you're able to attach the wheel to the motor firmly, it usually doesn't have enough 'oomph' to turn the wheel without a push-start. The trouble is that you've got too much speed and not enough torque at the wheel.

The motor will generate the certain amount of power, but you can use that power in different ways. For example, a fan needs to be turning at high speed to be of any use, so it makes sense to simply strap a propeller onto the shaft and power up the motor. However, if you need a motor shaft to spin more slowly and with more 'oomph', then you need to add a couple of gears to help you do this.

When we build these race cars with college students, we made larger versions that could really transport them across the parking lot. Only instead of a tiny hobby motor turning the pinion (the gear attached to the motor shaft) as we're going to do in our experiment here, the students powered their ride-on cars with a battery-powered drill they had to hold while riding it across the floor.

The biggest challenge students faced was selecting the gears. Depending the student's weight and rolling friction of the wheels, they would need to find the right gear combo for their car. The main thing to keep in mind is that you always trade speed for torque (twisting motion).

In the case with gears, the power is always the same (from the drill), but we slowed the rotation speed way down to increase the amount of torque (how much 'oomph' a wheel had to turn) in order to get it rolling. We're going to experiment with this idea by creating our own geared race cars. Are you ready?

Need help finding gears?

Materials:

• 5 popsicle sticks
• 2 straws
• 4 wheels or lids from film canisters, or milk jug lids (anything plastic, round, and about the size of a quarter)
• 1 gear set
• 2 skewers
• 3VDC motor
• AA battery case with AA batteries
• 2 alligator clip lead wires
• hot glue gun with glue sticks

Lesson #30: Steerable Waterbot

After you make the Waterbot, you can create a two-motor version that you can steer using a remote control! Material:

• 2 battery cases
• 4 AA battries
• 2 motors
• 2 propellers
• 4-10 alligator clip leads
• 16 popsicle sticks
• Empty water bottles
• Hot glue gun & glue sticks

Lesson #31: Robotic Cookie Snatcher

Are cookies out of reach in your house? When I was a small kid, the top of the refrigerator seemed MILES away... until I built a robot arm out of toothbrushes, popsicle sticks, and cardboard to reach it for me!

I've upgraded my old idea to include a motorized linear actuator so you can see how real robot engineers create linear motion (back and forth along a straight line) from a spinning motor. The motor AND nut both need to pivot for the claw to work, so take special note as to how the linear actuator (the scissors-looking thing) is built.

Here's what you need:

• piece of cardboard
• two fat popsicle sticks
• two toothbrushes or spoons or other things you can use as grippers
• two large paper clips
• four brass fasteners
• one LONG bolt with nut (either a hexnut or wingnut)
• one 1.5-3VDC hobby motor
• two AA battery cases with batteries
• alligator clip wires
• 3 thumbtacks
• cork from a wine bottle or small plastic gear from an old toy that fits onto your motor shaft
• scissors
• hot glue gun and glue sticks

Make sure that the motor can pivot on the popsicle stick or it will jam and won't move up the screw threads. This is the basis for many real, working industrial robots that need to lift very heavy loads.

Lesson #32: BumperBot

If you have a pet, they'll be sure to get a great workout chasing this nifty little robot. If you can, I totally encourage you to make two or more and have a contest!

This BumperBot is one of the simplest robots you can make that uses a touch sensor, tricycle gear, and simple parts from around the house. (And there's no computer programming required.) Using a switch that reverses direction upon impact, this robot will have your kid's mind-wheels spinning. Be sure to follow the wiring directions EXACTLY as shown or it won't work right!

Here’s what you need:

• four fat popsicle sticks
• two pennies
• 1.5-3VDC hobby motor
• two AA battery cases with AA batteries
• alligator clip wires
• 2 wooden skewers
• 2 straws
• three wheels or lids from film canisters, or milk jug lids (anything plastic, round, and about the size of a quarter)
• scissors
• hot glue gun and glue sticks

See if you can improve our design after you've built one. Here's what you do:

Okay, so - here's the deal: we're going to make a home-brew slide switch that will reverse the direction of the motor when pressed. You can add additional circuits to sound a buzzer or blink on the headlights when the motors reverse, too!

Lesson #33: BEAMBot Engine

This is one of the coolest applications of renewable energy to come about in recent years. BEAM stands for Biology, Electronics, Aesthetics, and Mechanics. It basically refers to a class of robots that instead of having complicated brains, rely on nervous-system type of sensors to interact with their world.

Some BEAM robots skitter, dance, flash, jump, roll, or walk, and most are solar powered. The result is a fast responding robot made of old cell phone parts that can fit inside your hand. We'll be making a few different types so you can get a good handle on this type of programming-free, battery-free robotics.

Most BEAM robots use the same solar 'engine'. The solar cell will convert sunlight into electricity, which will then be stored in our capacitors (think 'electricity tanks') until a certain threshold is reached... when the tanks are full, the robot begins to move. This means that you can leave them out all day, and they will sit and collect energy, then turn on by themselves until they run out of juice, then turn off, sit and recharge until they have enough energy to go again... and off they go! Let's walk through how to make a BEAM robot. Once you've got the hang of it, make a second solar engine from the rest of your parts and add any kind of body you want!

You'll need to get the following materials:

• Tiny eccentric vibrating motor (or Solorbotics, or you can also rip one out of an old cell phone)
• Vibrating disk motor from Solarbotics (you can also rip one out of an old cell phone)
• Two 2.2k-Ohm resistors (or Solarbotics)
• Six 4700 μf electrolytic capacitors (or Solarbotics)
• Two PNP 3906 transistors (or Solarbotics (get a few extras, as these are the first things to burn out
• Twp NPN 3904 transistors  (or Solarbotics) and get a few extras, as these are the first things to burn out)
• Two voltage triggers from Solarbotics (get the 1380-G or J or N)
• Two 37x33mm solar cells from Solarbotics (we won’t be using the circuit on the back – just the solar cell)
• Paper clips (a few of each: small and large)
• Hot glue gun, soldering iron with solder, electrical tape
• Pliers, wire cutters, diagonal cutters (if you have them)

Here's what you do...

Lesson #34: BEAMBot Trimet

This is one of the coolest applications of renewable energy to come about in recent years. BEAM stands for Biology, Electronics, Aesthetics, and Mechanics. It basically refers to a class of robots that instead of having complicated brains, rely on nervous-system type of sensors to interact with their world.

Some BEAM robots skitter, dance, flash, jump, roll, or walk, and most are solar powered. The result is a fast responding robot made of old cell phone parts that can fit inside your hand. We'll be making a few different types so you can get a good handle on this type of programming-free, battery-free robotics.

You'll need to get the Trimet Kit from Solarbotics. It has everything you need except the tools for the job (soldering iron, pliers, wire strippers, razor) and paperclips.

Here's what you do:

Lesson #35: BEAMBot Solar Roller

This is one of the coolest applications of renewable energy to come about in recent years. BEAM stands for Biology, Electronics, Aesthetics, and Mechanics. It basically refers to a class of robots that instead of having complicated brains, rely on nervous-system type of sensors to interact with their world.

Some BEAM robots skitter, dance, flash, jump, roll, or walk, and most are solar powered. The result is a fast responding robot made of old cell phone parts that can fit inside your hand. We'll be making a few different types so you can get a good handle on this type of programming-free, battery-free robotics.

To make this project, you'll need to get the Solar Roller kit from Solarbotics. You'll also need your soldering equipment and basic tools, like pliers, wire strippers, scissors, and electrical tape.

Lesson #36: BEAMBot MiniBall

This is one of the coolest applications of renewable energy to come about in recent years. BEAM stands for Biology, Electronics, Aesthetics, and Mechanics. It basically refers to a class of robots that instead of having complicated brains, rely on nervous-system type of sensors to interact with their world.

Some BEAM robots skitter, dance, flash, jump, roll, or walk, and most are solar powered. The result is a fast responding robot made of old cell phone parts that can fit inside your hand. We'll be making a few different types so you can get a good handle on this type of programming-free, battery-free robotics.

You'll need to get the MiniBall Kit from Solarbotics. It has everything you need except the tools for the job (soldering iron, pliers, wire strippers, razor), paperclips, and 80mm plastic ball (the kind found at craft stores for making your own holiday ornaments).

Here's what you do: