Playful Engineers 3 Step Sequence

Play-based learning is at the heart of everything we do at Playful Engineers, that’s why it’s in our name! And that’s why we encourage (though we don’t require) teachers to follow our 3 step sequence, making the most of the materials, and of what we have to offer as teaching artists, before, during, and after our live-streamed session/s. We’ve developed this sequence based on our experience in play-based learning, and informed by principles of Constructionism and UDL (Universal Design for Learning).

Allowing time for unguided activities makes room for play (in this instance, socially-driven play) to be the childrens’ best guide for self-directed learning. By making more room for play before and after the instruction, kids may be more able to deepen their understanding of specific concepts and skill sets through direct instruction coupled with related hands-on activities with the teaching artist.

Following this sequence (or making your own) also greatly increases the value of dollars you may be spending on materials costs and teaching artist fees.

Phase 1) Pre-Workshop Activities: exploration, discovery

Teachers are encouraged to introduce the workshop materials BEFORE the workshop session, allowing time for plenty of random exploration, discovery, and generation of creative ideas. Through this time of unguided and ungraded socially-driven classroom play, kids develop, try out, and assess their own and their classmates’ ideas about what might be possible. 

When we present the live-streamed session later on, Kids will tend to be less constrained in their work by ‘shoulds’, and at the same time, more open to the ‘coulds’ that we’ll demonstrate. 

You may choose to document this activity by taking pics and videos, and by making time for post-activity discussion. We provide suggestions to engage students’ own formative assessments both during and after the activity. Afterwards, students see a short video introduction from Playful Engineers which introduces Jay as a teaching artist, and outlines what to expect from the upcoming, live-streamed session. 

At any time, teachers are encouraged to invite Jay to view classroom pics, videos, comments and questions on a google doc, or through the ‘Flipgrid’ platform, before the live-streamed session, to enhance connection and engagement.

Phase 2) Live-Streamed Workshop: demonstration, inspiration, replication (from instruction to construction)

This is the live-streamed visit with teaching artist Jay Mankita. Prior to start time, teachers distribute the materials. The session begins with introductions, and some feedback from any comments, questions, pics, or videos, that may have been shared with Jay from the classroom’s prior activity. Next, Jay demonstrates and explains the basics of the mechanisms we’ll be building together.

Now Jay’s instructions begin, and the kids begin working with the materials, following step-by-step, and replicating the basic mechanical forms that will become the foundations of their individual creations. During this time, students may be planning, imagining, or trying to figure out their own modifications of the basic form, based on their own creative input – each at their own pace, and their own level of ability and understanding.

Phase 3) After the workshop: extension, integration, and reflection

Now teachers are encouraged to allow the class to access the materials for a longer period of time. Try polling the class for ideas as to how they’d like to set it up. Different students may want different things – competition, teams, total freedom, solo work – find what fits best for your classroom, and your teaching style, from free-form chaos to guided, curriculum-relevant activities.

Observe to what extent are students integrating specific techniques or approaches they may have picked up in Phase 2, with their own creative approaches and ideas. Allow time for student-driven discussion, and if possible, allow for different forms of expression other than verbal – does anyone want to draw a picture of their ideas?

Finally, make available when possible, more time, space, materials, books, videos, and other teaching resources* to the class, and especially to those students that want to deepen their understanding, skills, and relationship to this type of work/play.

Chain Reactions: How-to Build a Multi-Track Ball Feeder

A step by step STEAM tutorial on how to build a Track Feeder from your own toys or household materials.

This is an easy technique for your next Rube Goldberg machine, ball run, or any type of chain reaction. You can make it from your own stuff. A track feeder can change the direction and position of a rolling ball. Each track “feeds” the ball onto the next one. In the example above, I’m using Hot Wheels tracks, but I’ll also show you how I make tracks from cardboard, rubber bands, or even the tops of books. You can use anything that a ball will roll on. For our purposes, think of a track as a tilt-able flat surface with walls on the sides to keep the ball from rolling off.

This post is intended to teach one specific technique, and also to illustrate the idea that every complicated machine is made from simpler parts. Simple parts can be mixed and matched, through many different materials and uses. Consequently, the more we build skills and understanding about these simple parts, the more reliable our more complex machines can ultimately become.


Find, or make your own materials for building this project. Here are some suggestions:

  • Hot Wheels or other type of car tracks if you have them
  • Cardboard, plus scissors or craft knife, and ruler, if you want to make your own tracks
  • Blocks, or other objects to support tracks, and for blockers to deflect the ball.
  • Rubber bands
  • Ping pong ball, marble, or other small ball.
  • Popsicle sticks, dominoes, pencils, – or any objects to act as blockers
  • Assorted other things you think of or find to use!
image: Rube Goldberg Track Feeder Technique Materials
The basic materials

Gather Materials and Choose a Space to Work.

A floor or a table work well. You may not have all the same materials, so use what you do have – in other words, be creative, and make this project your own way. How it works is not dependent on specific materials, but on understanding the basic ideas behind it.

Rube Goldberg Machines begin with the end in mind.

Whether I’m building a big chain reaction from lots of different parts, or just one simple part, I almost always start at the end, working my way backwards. This method is so valuable that I tend to use it for each individual part. So with a track feeder, I prefer to start building from the bottom; that’s where the ball ends up – the “output”.

So the first track I build will be the last track the ball rolls down; let’s call it track Z. This ramp will be the output of your machine – the place where the ball ends up. If making a ramp seems simple, it really is, and it is the basis for the whole project! A ramp, or an inclined plane, is a tilted flat surface (and the most basic type of Simple Machine.)

image: Rube Goldberg Track Feeder Plan

I incline track Z by placing a domino, block, or other object underneath one end of it, then I begin building the next part. I use bigger blocks, dominoes, other household objects, and different kinds of building toys to make platforms for my tracks.

Make the First Ramp – Track Z.

image: Rube Goldberg Track Feeder Single Track
One Track Feeder – boring!

Add More Tracks, Platforms, and Blockers.

Let’s build another one. This is track Y, which will feed the ball onto the higher end of track Z. As a ball rolls down track Y, and falls onto track Z, it hits a blocker. The “blocker” absorbs some of the force, allowing the ball to change direction and continue on down the next track. If the blockers are small, they may get knocked over as the ball hits them – this effect makes things more interesting, at least to me.

image: Rube Goldberg Track Feeder Double Track
Two Track Feeder

Now add track track X, track V, etc…Each additional track is just another inclined plane, resting upon one or more supporting platforms – in the pictures above, my platforms are made from wooden blocks, but you can use any stable object you happen to have.

image: Rube Goldberg Track Feeder Triple Track
Three Track Feeder
image: Rube Goldberg Track Feeder Quadruple Track
Four Track Feeder

Tips & Tricks for your Rube Goldberg Track Feeder

Rubber Bands Add Friction!

More about rubber bands: I often wrap rubber bands around the blocks that I rest the tracks upon, in order to add friction which keeps the track from slipping. The more gently your ramps are sloped, the less of a problem you’ll have with slippage, but even so, the rolling of the ball might knock some tracks out of alignment with each test of your machine. Rubber band friction can really help keep things in place, which will make your machine more reliable. Some people like to use tape, but I prefer rubber bands because I can use them over and over again.

image: Rube Goldberg Track Feeder Rubber Bands for Friction
Rubber bands add friction and resist unwanted motion!

Keep Tracks Separate

Notice that I keep some distance between tracks, so they don’t touch each other. Each time you test or run your machine, your tracks may move slightly, slipping out of position. You are already minimizing this factor by using rubber bands for friction, and using simple, sturdy platforms, but keeping some distance between your tracks will make it even less likely that they will overlap each other. Otherwise, overlapping will likely cause the ball to get stuck in place.

image: Rube Goldberg Track Feeder Leave gaps between tracks

Simplify, Simplify!

A complex machine is made from simple parts. If the part is doing something more than, or different from what I want it to do, then I need to simplify it. I’ve included two examples to show you what I mean.

image: Rube Goldberg Track Feeder 
A track supported by an unsteady tower of dominoes
An unsteady platform

1) This tower of dominoes is not a simple platform. Rather than provide a solid, stable support, the dominoes may slip, slide, rock back and forth, and ultimately fall apart. In other words, the platform will be in motion, which is not what I want! To fix this, I made the part simpler by replacing the dominoes with a single block.

image: Rube Goldberg Track Feeder 
A track supported by a steady block with rubber bands for friction
A steady platform
image: Rube Goldberg Track Feeder 
A track that is too steep may slide off it's support
Too steep!

2) This steep ramp is not a simple part. The track will slide off because there is not enough friction. to fix this, I made the part simpler by adding another block to make the ramp less steep, and also by adding rubber bands for friction. Now when a ball rolls on the ramp, the ramp itself is less likely to be in motion.

image: Rube Goldberg Track Feeder 
A track supported by two steady blocks with rubber bands, and with a gentle slope, won't slip.
Gentle Slope

In Rube Goldberg, and in Life: Plan, Build, Test, and Improve; Learn From Your Failure Points, & Try It Again!

As you build, test, and test again. It may work this time, but not the next. Analyze the differences. Of course each failure is an opportunity to learn, and the more failures you can learn from now, the more success you’ll have later on, because you’ll have developed more understanding and better skills. So don’t despair! Feel your feelings, and then get up and try again… Growth mindset means we can acknowledge our failures, while allowing for future learning, growth, and success. Say, “It doesn’t work…YET! I can’t do it…YET!

The Terrible Failure!

Alternate Builds: Make Your Own Tracks From Cardboard

If you don’t have plastic car tracks, or if you just enjoy making things from scratch, try making cardboard tracks for this project. I prefer cereal box, or cracker box cardboard – lightweight, but plenty sturdy for this purpose. I cut the boxes into strips, fold up the sides using a ruler or other straight edge, and I’ve got a new supply of tracks!

Image: Cutting cardboard into strips to make tracks for Rube Goldberg Machines
Cereal or cracker box cardboard is lightweight and easy to cut and fold
Image: folding cardboard strips on a ruler to make tracks for Rube Goldberg Machines
Precise measurements are not always necessary, but I like a straight edge to fold along!
Image: after we've folded cardboard strips on a ruler to make tracks for Rube Goldberg Machines
Fold up the sides
A cardboard track for Rube Goldberg Machines
Voila! A cardboard track!

In the next video, see how I’ve used cardboard tracks and other household objects to make different kinds of track feeders.

Alternate Builds: Include Household Objects in Your Track Feeder

Notice some different properties for each type of object. In the first video of this section, the cardboard tracks fit right in with the home-made feel of this build. In the second video, see how rubber bands can be stretched around lids and books to make great tracks, too.

Alternate Builds: Booktop Track Feeder

In the final video, see how the tops of hard cover books make their own track feeder. The tallest book feeds the next tallest, on and on, all the way down to the shortest book. Each book is inclined gently with a domino, pencil, small plank, or other object. Use dominoes for blockers, or anything else you can find.

What Have You Discovered?

An engineer is someone who learns the best available science, and puts it to work. And the more you put it to work, the more science becomes available for you to learn. You’re learning by doing – that’s hands-on learning!

I hope you enjoy building a Multi-Track Ping-Pong Ball Feeder as part of your next Rube Goldberg Machine I’d love to see what you come up with – stay in touch!

Jay Mankita,

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Rolling Cone

Tinker Toy Rube Goldberg Cone

Rolling means moving along a surface by revolving, or turning over and over, and without sliding. When a cylinder rolls, it tends to roll in a straight line. But if one end is wider than the other, it will go around in a circle. I used to call this technique the “Differential Compass”, but now I just call it the “Rolling Cone”

There are many things that might be lying around your house that can act as a rolling cone. See what you can find.

A wide variety of rolling cones.
A panoply of rolling cones.

The wider side travels further than the narrower side with each rotation of the cone. If both sides were the same size, it wouldn’t be a cone, and it would roll in a straight path. Try this with other objects, and observe how the path changes, as you change the cone.
Two rolling cones are better than one.

All complicated machines are made from simpler parts. If you haven’t mastered this technique, or don’t yet understand it, break it down into smaller parts till you “get” each one, and then build up from there. Find or make a cone shape that will roll on a curve. Input force on one end, and the cone will output force at the end of its curved path. Place the cone on a surface slightly higher than the table, like a domino, which stores a bit of potential energy, and adds to the force of the rolling cone when that potential energy is converted to kinetic (movement) energy.

Popsicle Stick Catapult

A ping-pong ball sits on a tiny rubber band (a rainbow loom, or hair elastic) at the end of a popsicle stick.

A ping-pong ball sits on a tiny rubber band (a rainbow loom, or hair elastic) at the end of a popsicle stick. That provides friction to keep the ball in place. A small rod, spool, or domino acts a fulcrum. The catapult is a simple lever – a rigid object (popsicle stick) rotating around a fixed point, the fulcrum. Like a seesaw, but notice the fulcrum is not in the middle. The short end gets the force, and the long end sends the ball flying!

You can use a plastic spoon, or pretty much anything with a flat or rounded surface.

You can use a plastic spoon, or pretty much anything with a flat or rounded surface. The greater the incline (tilt), the higher the ball can go. Too much incline though, and the ball will roll off. As in the story of Goldilocks and the three bears, engineering (and life) is a dance between too much and too little, we’re always looking for the “just right”.

A ball in a spoon over a fulcrum

The potential energy is in the position of the block that is set to fall on the short end of the catapult. The higher and heavier the block, the greater the force. Newton’s second law says that for every action there’s an equal and opposite reaction. With a lever, as one side goes down, the other side must go up (conservation of momentum) as it rotates around a fulcrum. And we exchange force for distance, so the reaction (the flying ball has lots of distance) is equal to the action (the falling block has lots of force).

The last three steps at the end of a longer chain reaction, ending with a catapult

All complicated machines are made from simpler parts. If you haven’t mastered this technique, or don’t yet understand it, break it down into smaller parts till you “get” each one, and then build up from there. Find or make a lever, and place a fulcrum underneath it, off-center. Place a ball (or something else lightweight and soft) on the long end. Drop something heavy on the short end. Watch it fly!

Patient Ping Pong Ball

A ball will sit patiently upon the half-circle at the end of a track

A ball will sit patiently upon the half-circle at the end of a track. If you are making your own track from cardboard, use scissors, or better yet, a large hole-puncher if you have one, to make the half-circle.

The forces of gravity and friction keep the ball in place. That's Newton's first law - the law of inertia

The forces of gravity and friction keep the ball in place. That’s Newton’s first law – the law of inertia. That means that a body (an object) at rest tends to stay at rest, and a body in motion tends to stay in motion – with the same speed and in the same direction, until some other force makes it change. Like a kid who doesn’t want to get out of bed in the morning (body at rest), and then insists on staying up late at night (body in motion). Whatever force the parent exerts needs to be greater than the force keeping that kid asleep, or awake!

We have stored potential energy. The patient ping-pong ball waits patiently till some force or object transforms its potential energy into kinetic (movement) energy. And so, I am reminded to be patient with myself, especially when I am failing, which happens a lot, and in failing again and again, I am storing more and more of my own potential energy for me to release in my quest to understand how the world works, and to help make it work even better.

All complicated machines are made from simpler parts. If you haven’t mastered this technique, or don’t yet understand it, break it down into smaller parts till you “get” each one, and then build up from there. Find or make a track with a half-circle at the end. Lean the track to make a ramp. Place a ball gently upon the half-circle. Change the size of the half-circle if needed. Let one ball tap the next. Repeat.

Gather Household Materials

Suggested Materials List

Surfaces: table, floor, shelf, counter, flat board,

Tools: drill, ruler, scissors, hot glue gun, hole punchers, 

Toys: Hot Wheels Tracks, Tinker Toys, K’Nex, Legos, dominoes, popsicle sticks, railroad tracks, marble runs, action figures, 

Tracks: cardboard, stretched rubber bands, booktops,

Balls: marble, ping pong ball, golf ball, rubber ball, rolled up aluminum foil, baseball, tennis ball,

Building Blocks: blocks, scrap wood, cans, boxes, bins, chairs, stools,

Tubes: Paper towel rolls, toilet paper rolls

Fasteners: rubber bands, glue, hot glue, tape, brass fasteners, string, wire (from clothes hangars), clamps, clothespins, twist ties, pipe cleaners, magnets,

Pullers: string, chain (lightweight), ribbon, floss, fishing line, shoelace, tape,

Rollers: balls, plastic containers, toy wheels, toy cars, fruits & vegetables, cans, tubes, dowels, cone shapes, lids, tape rolls, tape roll inserts, nuts & bolts, discs, paper wheels, spools,

Dominoes: dominoes, clothespins, CD cases, cassette tape cases, books, folded playing cards,

Weights: dominoes, blocks, coins,

Spinners: blocks with holes (bushings), rods, pen and marker housings and caps, things that turn freely like swivels (lazy Susans),