How to bring tech and making into any classroom! (1/4)

Turns out Ms. Frizzle from The Magic School Bus had it right all along! In the era of the Next Generation Science Standards, there is a great deal of evidence that experiential and project-based learning are effective approaches to education. As described in the Cambridge Handbook of Learning Sciences, project-based classrooms provide opportunities for students to “investigate questions, propose hypotheses and explanations, discuss their ideas, challenge the ideas of others, and try out new ideas.” All of this leads to higher test scores than in traditional classrooms.
While we educators may lack the magic necessary to shrink our bodies or travel through the solar system, technology can be an excellent, “magic-like” tool for teaching project-based learning across a wide variety of subjects. When implemented with care and intention, electronics and tech can enhance and expand the realm of possibilities, providing students with direct, hands-on experience of phenomena. A handful of carefully chosen equipment and materials provide an open-ended platform for endless variations of creativity, application, and exploration.
One of the major obstacles in getting started is figuring out what, and how much, to choose. The plethora of options can be daunting and it is not always obvious how to incorporate into a classroom. Here are four principles to help guide you as you make lesson and product choices:
1. Use what you have;
2. Let the students lead (peer-to-peer and even peer-to-teacher education);
3. Broken is better; and
4. Pass it on!
The remainder of this article will expand on the first principle: Use what you have. We will publish more in-depth articles on the remaining principles in the weeks to come, so stay tuned!
Principle 1: Use what you have.
Whether you are looking to teach history or robotics, there are many learning opportunities within everyday materials, particularly when paired with “smart” devices like computers, microcontrollers, or other Integrated Circuits (“ICs”).
Investing in an appropriate microcontroller* for your classroom gives your students more diverse options for projects and invites cross-disciplinary learning opportunities, a key foundation of NGSS. Microcontrollers can add coding to art, and art to coding. If you need some help choosing an effective microcontroller for your classroom, here’s an overview of some common, beginner-friendly microcontrollers.
Free or inexpensive components can be used in alternative ways: LEDs are also light sensors, motors generate electricity when spun, and speakers can be used as a microphone! Finding alternative uses for parts offers students a fun challenge and is a great way to explore connections across fundamental phenomena: Why is a motor also a generator? What does this tell us about how electricity and magnetism work together?
Encourage your students to ask deeper questions and look for connections.
Is there a closet full of old computers, telephones, printers, etc? Perfect! Old tech is often easier to understand because the pieces inside are larger and easier to see than in newer technology. Larger parts are also easier to harvest, or pull out for closer examination and/or use in other projects.
Guide the students in taking apart unused devices. If it’s broken, can the students figure out why? Is it possible to fix or hack it to do something different? If not, how could the students use the parts in new ways? What parts might the students harvest for other projects?
Here is a list of some parts that can be harvested without specialized tools and used in a wide variety of projects:
  • Motors
    • Motors can be used in a wide variety of projects including robotics, puppet shows, art projects, and creative music-making. This is a wonderful alternative to traditional robotics programs as it allows for a wider variety of ingenuity and a deep understanding of how motors function.
    • There are different types of motors that require different signals to turn on: DC motors, stepper motors, and servo motors are the most common. DC motors can be powered directly with a battery, while stepper motors will require a more finely tuned signal from a computer or microcontroller. Unsure what type of motor you discovered? Use three or four AA batteries or a 9V battery to touch the motor connections and explore how and when it moves.
  • Speakers
    • From special effects to science experiments, sound is exciting! Harvested speakers offer the opportunity to observe how sound waves are generated, how sound travel through different materials, and how waves move in general.
    • Connect a 9V battery to the speaker terminals to move and “beep” it, or use the speaker with a microcontroller and/or other amplifier circuit to create instruments, sound effects, and music. Speakers can also be used as an input when connected to an audio amplification circuit.
  • Electromechanical parts like switches, pushbuttons, relays, and connectors
    • Switches and buttons provide a way for us to interact with circuits and electronics. They can be used to explore analog and digital signals, build logic gates, create cause-and-effect machines, and design communication systems, as well as many other possibilities.
    • A relay is an electronic switch for two separate circuits that make a “click” sound when activated. Relays are one way to control motors with a lower-power circuit.
    • Electrical connectors come in an astounding variety of types, shapes, mechanical and electrical connection mechanisms. They help make the electronics sturdier and easier to store, transport, and modify. And of course, they can be used to add flair to projects sans electricity!
  • Sensors
    • Many electronics have infrared (IR) transmitters and/or receivers, which can be hacked to build remote controls for robots and other projects. Solar path lights and CD/DVD drives contain light sensors, security lights have passive IR sensors, and many printers have optical encoders!
  • Transistors
    • If you have tech that qualifies as antique, you may be able to find transistors that can be reused (in newer tech, they are so small that they are invisible to the human eye). Observing transistors in older tech is an excellent pathway through computer history, design, and hardware function.
    • If observation of transistors isn’t the educational opportunity you need, they can be used to add autonomy and logic to circuits, or can act as a controller for output devices like lights, speakers, or low-power motors.
  • Mechanical parts like springs, gears, drive shafts, etc.
    • One of the main challenges in doing engineering projects is having make functional gears. Avoid all of that by taking apart a printer and pulling out the mechanical components. Electronic toys that move are another good source for gears and mechanical mechanisms, and can be hacked or “mashed” together in combinations that span delightful and eerie.
A quick note on safety when doing take-aparts:
  • Unplug the electronics and leave unplugged for a minimum of two (2) weeks.
  • Avoid large appliances, microwaves, and ink-jet printers (or just take out the ink cartridges)
  • Always wash hands afterwards. Students should keep food and drink in closed containers and off the tables.
  • Do not force anything open or closed. The biggest hazard with take-apart activities are sharps caused by broken parts when someone tries to pull a case open without properly removing all the screws.
Even without harvesting parts, seeing the inside of electronics is an effective and memorable way to explore how these devices are made and how they function. Once students see the insides of a few different devices, they will quickly identify connections across all electronics and have a better understanding of the “magic” behind the tech.
Aside from electronics, there are tons of useful and versatile materials all around us! Cardboard, paper, plastic containers, pipe cleaners, brads, clothespins, and office supplies are incredibly versatile. Use these materials in conjunction with the tech you have available, or as stand-alone project-based lessons in science, math, history, and other subjects. How might your students explore various ways to build moving mechanisms with cardboard and paper brads? How might your students use colored paper to explore how light is absorbed and reflected? How might your students explore and visualize sound?
Often, the key to incorporating project-based learning is providing the appropriate challenge. The best challenges allow for a wide variety of creations, are accessible and relevant to the students’ lives, and are as fun to mess up as they are to achieve! Challenges do not need to be binary or only one goal or path-oriented. The most effective challenges are those with the most room for surprises and “broken” rules.
With all of that said (well, written), the only thing you really need to remember is that you can do a lot, including incorporating and meeting NGSS, with what you already have. Look around, look inside, and look for connections!
Please reach out if you have any questions about this principle or if you’re looking for ideas in getting started. Happy learning!
* Wait wait wait… what is a microcontroller? Excellent question! A microcontroller is a “simple computer” that runs one program at a time. Examples of microcontrollers are Internet routers, TV remotes, and video game controllers.

micro:bit Dog Door Opener

​Do your pets trap themselves in rooms? Do you wish you could make your home more accessible for your furry* friends?? Now you can, hooray!!

This project uses a micro:bit microcontroller to pull open a door when a (pet-friendly) switch is pushed. We’ll need a micro:bit (probably helpful), a high-torque motor, and some mechanical parts and pieces to mount the motor and connect the motor to the door.

Read Time: ~15 min

Build time: ~30-45 min

Cost: ~$60

*This project can be used as a low-cast way to improve home, workplace, or other physical space accessibility for humans, too! Yay!!

 

Materials

  • ​micro:​bit 
  • microUSB cable (3ft or more)
  • ​Binary Bots Planet Totem Spider Kit​
    • If this is your first robotics project, I’d highly recommended to use this kit and follow the tutorial as-is. If you’ve done a few projects before, feel free to make adjustments and modifications. Here are two things to keep in mind:
      • This project requires a high torque motor to pull open our door. The motor control system and high torque mini DC motor from this kit were super helpful in building this project.
      • The assorted boards, nuts, and bolts were also handy, but could be replaced with similar mechanical parts from another robotics kit or directly from a manufacturer.
  • 2 lengths of 24 gauge stranded wire, 3 – 4ft (1 – 1.3m)
  • Fishing line, 4′ (1.3m)
  • Aluminum, 2″x3″ rectangle (5 – 7cm)
  • 8 small nails
  • 6 push pins
  • Wall sticky putty

Tools

  • ​Driver kit
    • Note: the Binary Bots kit does come with an M3 driver (and it’s magnetic, wooo!!!) and a tiny screwdriver.
  • Hammer
  • Wire Strippers
  • Hot Glue Dispenser (not pictured)
  • Scissors
  • Measuring Tape
  • Pencil

Prep and Aluminum Latch Cover

​1. Measure and record the width of your door (the inside part).

2. At a 45 deg angle, measure the distance from the door latch to the wall perpendicular to the door hinges.

Note: your particular room setup is likely different than mine. The key thing to keep in mind is that torque is the lowest when it is applied perpendicular. In other words, try to attach the motor as close to perpendicular as possible. A 45 deg angle is likely the smallest angle you’ll want, larger angles will be easier for the motor to pull open the door.

3. Cut a 2″x3″ piece of aluminum (e.g. from a recycled can).

 

Build it: Door Connection Mechanism!

Materials

To build this part, you’ll need the following pieces from the Binary Bots Kit:

  • 3 100x30cm boards
  • 2 2-hole 90deg brackets
  • 4 6mm M3 bolts
  • 4 lock nuts
  • 2 8mm M3 bolts
  • 2 M3 nuts

Procedure

1. Grab one of the boards. From the left edge, measure and mark the width of the door.

2. Grab a second board. Connect the second board to the first perpendicularly to each other, so that the second board is just to the right of the door width line.

To do this, use both brackets, 4 6mm M3 bolts, and 4 lock nuts.

3. Grab the third board and connect it to the second in a straight line using the longer (8mm) M3 bolts and rectangular M3 nuts.

Set aside and move on to the next part, woo!

Build it: Pet-Friendly Switch!

​Materials

To build this part, you’ll need the following pieces from the Binary Bots Kit:

  • 2 100x30cm boards
  • 4 6mm M3 bolts
  • 4 M3 nuts
  • 2 8mm nylon standoffs

You’ll also need:

  • 2 3-4ft (1-1.3m) of stranded 24 gauge wire
    • Remove about 1in (2.5cm) of the insulation from both ends​
  • 3 push pins

Procedure

1. Grab one of your boards and attach the nylon standoffs to the left side using two (2) M3 nuts.

2. Grab the second board and use two (2) M3 bolts to secure the second board to the first via the nylon standoffs.

3. Grab one of the M3 bolts and push it through a hole on the far right end of the top board. Wrap one end of the wire around the base of the bolt. 

4. Use an M3 nut to secure the bolt in place.

5. Repeat steps 3 and 4 for the bottom board, making sure that the second bolt is directly below the first.

When you close the switch (aka push the boards together), the top and bottom bolts should press together and make full contact.

Build it: Motor Mount!

Materials

​To build this part, you’ll need the following pieces from the Binary Bots Kit:

  • 1 100×100 cm board
  • 1 Tiny Motor with 2 tiny screws (so cute and yet so powerful!)
  • 1 Motor Mount (“web launcher”)
  • 1 reel set (“web reel”)
  • 6 6mm M3 bolts
  • 6 M3 nuts

You’ll also need:

  • 6 small nails
  • 1 pushpin​
  • 4ft (1.3m) of fishing line (or equally strong line)

Procedure


1. Insert and secure the motor into the motor mount with the two tiny screws (highly recommended to use a larger screwdriver if you have one..)

2. Grab the 100x100cm board and use the 6 M3 bolts and nuts to attach the motor on the left side in (roughly) the middle.

3. Grab the reel and fishing line. Thread one end of the fishing line through the middle of the reel, then wrap around the teeth. Secure with a dab of hot glue.

4. Push the two reel pieces together (pinching the thread between the two pieces), and insert into the motor drive shaft so that the web part faces outward. Secure with a dab of hot glue on the outside.

Connect it: Electronics!

Materials

  • micro:bit
  • microUSB cable
  • Binary Bots motor driver board
  • 3 AAA batteries

Procedure

1. Grab the Motor Mount setup you just put together, and plug in the motor to the motor driver board.

Connect the red motor wire to the left header pin labeled “Motor1”. Connect the black motor wire to the right header pin labeled “Motor1”.

2. Connect the pet-friendly switch! Connect one of the switch wires to the micro:bit P0 pin, and the other to the micro:bit GND pin (doesn’t matter which switch wire goes where).

3. Insert the micro:bit into the motor driver board so that the pushbuttons are facing outwards (away from the motor driver).

4. Insert the batteries into the motor driver board. Locate the power switch and move to “off”.

Code it: Motor Control!

Navigate to the Make Code website: www.MakeCode.org and select the micro:bit option, then “New Project”. It is recommended to rename your project to help you identify what it is doing, like “DogDoorOpener”.

Some background info: 

When Pin P0 is triggered (via the switch closing), we want to turn the motor so that it pulls open the door by spooling (aka reeling in) the fishing line. We also want to unspool the fishing line so we can shut the door again. It is also helpful to have a manual way to spool and unspool the motor, as well as to cut power to the motor.. just in case!

Since we are dealing with a DC motor, when we give power to one of the motor leads and ground the other, the motor will rotate in one direction. When we switch power to the motor leads, the motor will rotate in the other direction. Cutting power to both motor leads turns off the motor.

Let’s get started!

First Code Function: Motor Triggered by Doggo Switch

1. Pull out a “when pin is pressed” (input blocks) and make sure it is set to pin P0.

2. Inside the pin P0 block, use the digital write blocks to turn on micro:bit pin P13 (set to 1) and turn off micro:bit pin P14. This turns the motor on in one direction. 

The digital write blocks are found under Advanced –> Pins. Select the appropriate pins by clicking on the down arrow.

3. Add a pause for about 7s (7000 ms), then turn the motor off by setting P13 and P14 to 0.

Note: 7 seconds worked well for my setup and my doggo’s needs, but definitely check that this is enough (slash not too much) time to adequately open your door for your needs.

4. Unspool the motor (aka rotate it in the reverse direction) by using a digital write block to turn on P14 and turn off P13. Be sure to unspool the same amount of time as you spool.

5. Optional: use the LEDs to include a countdown/count-up timer to let you know when the motor will be turned on. Also recommended to add a pause between when the switch is pressed as well as when before the motor unspools.

Second Code Function: Manual Open

1. To make a manual switch, drag out a “On Button A pressed” (input blocks).

2.  Inside this block, use the digital write blocks to turn on micro:bit pin P13 (set to 1), and turn off micro:bit pin P14 (set to 0).

3. Add a pause block for ~3s (3000 ms).

4. Turn off the motor! (by setting the digital write blocks to 0)

5. Optional: Show an icon before you turn the motor on so you know which way the motor will be turning.

For mine, I chose a rectangle outline so indicate “open door”, choose something that makes sense to you and your brain.

Third Code Function: Manual Close

1. To make a manual switch, drag out a “On Button B pressed” (input blocks).

2.  Inside this block, use the digital write blocks to turn on micro:bit pin P13 (set to 0), and turn off micro:bit pin P14 (set to 1). 

3. Add a pause block for ~3s (3000 ms). 

4. Turn off the motor! (by setting both digital write blocks to 0)

5. Optional: Show an icon before you turn the motor on so you know which way the motor will be turning.

Fourth Code Function: Turn Off Motor

1. Pull out a “On Button A+B pressed” block.

2. Use two digital write blocks to set both P13 and P14 to 0.

Install it!

1. Use some of the wall sticky putty to wrap the aluminum around the door latch.

Bend the aluminum around the latch so that the door is able to fully close, but prevents it from sticking.

2. Using your hot glue dispenser, glue the short end of the door mechanism piece to the door width, just below the latch. Glue the longer piece to the door to provide extra stability.

3. Attach the motor mount and the motor controller board to the wall. Use the push pins temporarily to hold the pieces in place, then use 6 nails to secure the motor controller, and 2 to secure the motor controller board.

4. Use the wall sticky putty to attach the switch in a place that is convenient for whoever will be triggering the door to open. Since my dog is fairly large, I installed it about 1.5ft (0.5m) up from the floor so that doggo could press the switch with his nose.

I preferred to sticky putty so I could adjust the switch and remove things as necessary, but if you want to make this permanent you can use nails or hot glue.

5. Use the pushpins to secure the switch wires to the wall and prevent them from getting disconnected.

6. Attach the fishing line between the motor reel and the door mechanism. Close the door fully, then wrap the fishing line around the door mechanism a few times so that it is taught, then secure with hot glue.

Test & Deploy! And make your home more accessible, hooray!

​Huzzah!! Ready for the testing phase! Power up the micro:bit (via the microUSB cable) and turn on the motor controller board.

Trigger the switch and check that the motor pulls open the door enough for your furry friend to escape! And also that the motor unspools so you can close the door again.

Very likely something will need to be adjusted/fixed, so check all of the buttons, make sure the system is secure to the wall and does not block anything.

Once you’ve tested your Doggo Door Opener, show it to your pet! … And maybe train them, ha. I did this by using treats on top of the switch, so that my dog accidentally triggered the switch, then he saw that door opened. It took a few tries (I also ended up giving it a command of “get the switch”), but eventually he figured it out! And now I can leave my lovely but oh-so-anxious dog home alone without worrying he will trap himself (on purpose? I have no idea).

Hooray for using tech to make our own lives and the lives of others easier and better!

Let me know if you have any questions, run into any issues, or have other ideas for this project, I’d lovelovelove to see what you make so please share your creations!

Happy making, friends!

Student Project: Mini Robotic Table!

I am so proud of all of my students, especially when they tackle and conquer difficult projects, like one of my students did recently when she completed a prototype of her Mini Robotic Table.

… A Robotic Table?! Heck yes!! It is just as hilarious and awesome as you are imagining.

But like most projects, the build process was challenging and frustrating, but also delightful and oh-so-rewarding.

This young lady started this project at the age of 10 years old. Initially, she wanted to build a full-size table. After building a real table from scratch and adding wheels, together we discovered that adding remote control to this heavy object would be very challenging and expensive.

So, we revisited her concept and she decided to scale the table down to American Girl doll size. *swoon* SO CUTE.

For the next few months, my student took what she learned from building the large table, and created a miniature version that perfectly fits the height of her adorable American Girl dolls. She successfully built the table, added wheels, and build a remote control system to drive the table around.

I guided her throughout the process and assisted where necessary, but the concept and all of the build was done by her hands. Further proof that kids and young folks are capable of so much when we provide them with opportunities and just a lil’ bit of guidance. If you have children of your own, or if you are an educator, trust that they are so much more capable than we think! Challenge them, give them tools and supplies and let them freely create the things they want to — I promise, they will learn so much more than if we force them to learn the things, and in the ways, that we think we should, simply because “that is the way that we have learned.”

Remember Grace Hopper’s brilliant advice: The most dangerous phrase in the language is, “We’ve always done it this way.”

Check out the hard work of this young lady by reading our write-up here, and if you’re feeling inspired, build your own robotic table by following her instructions!

 

Mini Robotic Table

What’s better than a table with wheels? A table that you can drive around! This tutorial will teach you how to build your very own Mini Robotic Table, a project that was conceived and designed by one of my students (she was 10 when we started).

We built this table because, in the words of my student:

“I wanted to build something and I thought of a table and I thought of robotics and I smooshed them together. I like woodworking and I like robotics and I wanted to do something with the both of them.

We started w/ a full size table but that took a lot of time and money so we decided to make a tiny version, which is a prototype to the big one.”

We sized this mini table for American Girl Doll height (an American Girl doll is 18″ tall so we made the table to be 9″ tall), but you can adjust and modify depending on your needs. The most important thing to keep in mind is table weight, as a larger table requires larger motors and more battery power.

Difficulty level: Intermediate

Estimated build time: a few days to a week

Cost: ~ $75 – $100

Adult supervision required (lots of sharp and powerful tools involved)

 

Supplies

Materials

  • Wood
    • Table top: 8″ x 16″ (width x length)
    • Legs: 1.5″ x 1.5″ x 8″ (width x length x height)
    • Table Shelf: 8″ x 14″
  • Brackets (8)
  • Screws (28)
    • For brackets: 1.25″ screws
  • Axle, metal
    • We used the metal rod from an old (aka broken) french press
  • 4xAA Battery case and (4) AA batteries
  • Continuous rotation servos (2)
  • Small screws to hold wheels onto servo (2)
  • Radio controller and receiver
  • Servo Wheels (2)
  • Caster Wheels (3)
    • we used the same wheels as for the servo motors, but attached them to an axle instead of a servo.

Tools

  • Hot glue dispenser and glue sticks
  • Power Drill
  • Drill Bits
  • Screwdriver Bits
  • Saw
    • Or get pieces cut at your local hardware store
  • Sandpaper
  • Glue
  • Electrical Tape or heat shrink tube
  • Safety glasses
  • Dust mask
  • Scissors
  • Measuring tape
  • Level
  • Clamps
  • Optional:
    • Duct Tape
    • Velcro
    • Zip Ties

Tips, Tricks, & Extra Information (Please read before building!)

Before you build anything, read the full project instructions first!

Helpful info to have before you start this project:

1. Be prepared for drying time

2. How to use power tools and know safety rules.

Safety rules: put hair up, eye protection, roll up sleeves, no loose clothes, no jewelry that could get in the way, always have a second person in the room especially an adult if you are younger, dust mask.

3. Be prepared w/ the materials and tools you’ll need.

4. Document in a notebook as you work for reference later.

5. Find a radio controller that comes with a receiver. It is easier to put together the electronics if you get a controller and receiver together because it will take a lot more time to figure out which receiver will work with a particular controller, so get a controller that comes w/ the right receiver.

RC controllers can be very expensive, and other ones are super cheap and don’t work well. Read the entire description for the controller and receiver that you are interested in. The way we figured it out was by finding three options: one that was expensive, one that was in the middle, and one that was cheaper. We used our budget to help figure out the best option, and ended up selecting the option that was in the middle.

Build the Table!

Gather your woodworking tools, wood pieces, and brackets (see Supplies section for sizes). Remember to measure two or three times before drilling, gluing, and/or cutting 🙂

Step 1: Determine placement of legs and brackets and mark all bracket holes with a pencil. 

We used 2 brackets for each leg and 4 screws for each bracket, except for two brackets that overlap in between the legs.

It is helpful to use a tape measure to get placement as accurate as possible.

Step 2: Attach legs to the tabletop with brackets and screws.

A. Drill small holes in the tabletop and table legs to avoid cracking the wood. (See photo)

B. Attach two brackets to each leg.

C. Attach legs with brackets to table.

Step 3: Add the table shelf!

We cut ours to fit between the legs and attached with wood glue.

Tip: Add an object under the shelf while it is drying so the shelf does not move.

 

Step 4: Sand the table where needed.

Step 5: Measure the height of the wheels and include in the total table height.

Connect the Electronics!

1. Set up the radio controller and receiver.

Bind the receiver to the controller as shown in the instructions that come with the controller that you chose.

2. Connect the battery case to the radio receiver.

Connect the battery pack to the pins that say “B/VCC” (black wire goes on the outside of the receiver).

For this table size and weight, four AA batteries are enough to power the receiver and the two continuous servo motors. If you build a bigger table, you’ll need larger motors and more battery power.

3. Do a quick test to figure out which receiver input plugs work best for driving your table with the controller.

For the test, do the following:

If you are using the same radio controller and receiver, we recommend using receiver channels 2 and 3.

A. Connect one motor to the first channel on the receiver. Align the servo wires with the receiver channel as shown in the photo above.Then move the controls on the controller, observe when and how the motor moves, and record your findings.

B. Move the motor to the next receiver channel and repeat Step 2A. Do for all channels on the receiver.

C. Decide which channels work best to drive your robotic table!

Build the Drive Train and Attach Wheels!

The drive train is how we connect the motor and wheels to the table.

Step 1: Attach the wheels to the servos.

We attached the wheels with screws, but we had to find screws that fit and held the wheels on tight. We also had to drill out a bit of the wheel where the hole is so the screws could fit through. You may need to do a bit of testing to find the proper screws.

Step 2: Figure out placement of the servos and wheels. Use tape to hold in place while you test.

Use a level to make sure that when you attach the wheels the table is not all wonky. Measure how tall the servo with wheels are going to be before you attach them and before you drill into the wood. If you do not measure them, the table might be too tall and disproportionate.

Step 3: Attach the front castor* wheels to the table using the metal axle.

A. Measure and mark the location of the axle so that the castor wheels are even with the back wheels.

B. Drill holes into the front table legs and push the axle through, adding wheels as you go.

C. Secure the castor wheels in place by adding hot glue or grommets** on either side of the wheels, leaving about a 1/2″ (1cm) gap so that the wheels can rotate freely.

*The front wheels are called “castor” wheels because they are not connected to the motor.

** A grommet is circular rubber stopper, sort of like a rubber band, that prevents the wheels from sliding off.

Step 4: Secure the servo motors with epoxy or another strong adhesive.

Note: We recommend doing this step after testing the whole table as the servo motors will be stuck once the epoxy dries.

Test, Drive, & Decorate!

Power up the radio receiver and controller and test out your robo table! It might take a few practice trials to get a feel for driving the table.

Once you’re sure the table is working, add some hot glue (or epoxy) to hold wires in place and prevent the electronics from getting disconnected.

Decorate your table with markers, paint, stickers, fabric… whatever your creativity compels you to do!

If you want to see optional upgrades, check the next slide. Otherwise….

You’re done! Enjoy driving your robo table, maybe to give your pets a lil’ exercise or to deliver you or a friend food when you are watching a movie. Share your ideas and creations with us, we’d love to see!

Optional Upgrades

Battery holder!

We made a battery holder using wood, felt, ribbon, and wood glue. We measured the battery box and cut small pieces of wood to make a box without a top. We used the felt to cushion the battery box and keep it in place, and the ribbon to more easily pull the battery box out.

Wire Tubing

We purchased some wood-colored cord cover and cut it to fit the sides of the table legs to conceal the servo wires.

Brakes!

Design your own braking system, or stay tuned for separate tutorial on how we tackle this!

How to use a Breadboard!

Used by hobbyists and professional engineers alike, breadboards allow us to quickly build all sorts of circuits!

Breadboards got their name because in a time long ago, engineers used to use wooden cutting boards! They would hammer in nails and wrap wires to make connections. Not only was it tedious, but the cooks got frustrated that their breadboards kept getting stolen and used for definitely-non-food-purposes, so eventually someone invented the plastic breadboard to keep kitchen utensils safe. Hooray!

Similar to wires, plastic breadboards use conductive metal and insulating plastic to create paths where electricity can flow (the metal parts), and breaks where it cannot flow (the plastic parts).

If we were to look underneath a breadboard and peel off the backing, we would see something like this:

What do you notice?

The middle of the breadboard is different than the outsides. On outside of the breadboard, on both the left and the right sides, there are two long strips of metal. These are called “Power Rails”, or “Power Buses”, and one of the strips by itself is called a “Power Bus.”

Flipping the breadboard back over, the top, where we make our circuit connections, looks like this:

Looking at our Power Buses, there are colored lines next to them. While these are just guidelines (ahhhh sorry for the terrible pun, lol), the colored lines are super helpful for keeping track of how we connect our battery or power supply to the breadboard. Typically blue means negative, or ground (“gnd”), and red means positive.

The middle gap of the breadboard is called the trench. This separates the two identical middle halves of the breadboard. The trench is sized so that components with more than 3 pins can fit across.

The rows of the breadboard are marked with numbers, in this case numbers 1 – 30. The columns are marked with letters A, B, C, D, and E. Each row has a set of 5 holes that are connected by the piece of metal we saw on the bottom, as well as metal pins on the inside that hold wires and component pins in place. Some of the hole groups that are electrically connected are shown on the photo above with red rectangles.

Now let’s make some circuits! We’ll need four (male-to-male) jumper wires and the following parts:

Next, we’ll connect the battery to the power rails. If your battery case does not plug directly into the breadboard, grab two jumper wires for this.

The battery case that you are using might change how you connect your battery to the circuit, and that’s okay! The important part is that you connect the positive side of teh battery to one power bus, and the negative side of the battery to the other. Be sure that both sides of the battery are in different power buses (if you feel the battery getting warm it may indicate that it is short-circuited, this would be the place to double check).

Next, let’s connect our light! Grab your remaining jumper wires and your LED.

Insert the LED legs so that both legs are in two different rows (reminder: rows are marked with numbers). Connect the positive side of the battery to the longer LED leg. Connect the negative side of the battery to the shorter LED leg.

Voila! If the LED is connected to the battery in a circuit, it will light up!

Try moving your LED to a different part of the breadboard. Observe what happens!

Does wire color matter? Try two different colored wires and see what happens!

Finally, let’s end our exploration by tracing the path of the electricity.

Electric current is defined to flow from positive to negative. That means our electric current, which is made up of moving charges, flows out of the positive side of the battery, through the wire and into the breadboard power bus. It flows through the power bus, then up and out the red wire to the breadboard row where it can travel up the LED where it does work (and loses some energy) to make the LED turn on.

Then the (less energetic) electric current flows out of the LED through the shorter leg, into the breadboard row where it flows into the black wire. It then flows out of the black wire and into the second power bus, through the power bus and back to the negative side of the battery.

Our circuit is a circle! The moving charges that leave their home must also come back, but they come back more tired and into the back-door (which is to say, the negative side!).

Other helpful terms:

  • Current: The amount of charge flowing past a point in our circuit.
    • Current units are given in Amperes/Amps, or A
  • Voltage: The potential energy, or pushing force, across a component in our circuit. A higher voltage means more pushing force.
    • Voltage units are given in Volts, or V.
  • Resistance: How much a particular component resists the flow of electricity.
    • Resistance units are given in Ohms, or O
  • Capacitance: How much current a battery can provide over time.
    • Capacitance units are given in Amp-hours, or Ah.

There are two ways to connect components:

1. In series: connect components in line with one another, or head-to-tail.

2. In parallel: connect components in loops, or head-to-head.

Going Further!

You are now ready to tackle more circuits! Try adding more lights, or using different components. What happens when you add different kinds of components together? How many ways can you combine multiple components ?What sorts of projects could you use these circuits for? Share your creations with us, we always love to see and share!

And of course, please let us know if you have any questions, we are here to help!

Other useful tutorials:

Happy making!