How to build a simple electric motor

How to build a simple electric motor

Today, I am going to demonstrate how to make a simple electric motor. This is a great activity for kids and adults, on rainy days or for science fairs. I’ve done this one with kids aged 8-12 ish, but it is a good all-ages activity, depending upon the amount of preparation you can do in advance, as well as the amount of help you are able to give while running the activity.

There are many different electric motor activities out there, with hundreds of minor variations. Mine is based upon this one with modifications to make it cheaper, as well as to use materials I already had available.

First off, here is what the finished product looks like when it is running:

Tools needed include:

  • pliers (1 or 2 pairs)
  • glue gun and glue
  • scissors
  • small piece of sandpaper
  • pencil
  • a glue stick tube (or other small tube-shaped object to wind the wire around)

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Consumables needed include:

  • base of some sort (any kind of scrap wood will do) about 15 cm square
  • 4 large safety pins
  • copper wire (22-26 gauge enameled, approximately 60 cm of wire per motor)
  • ferrite magnet (disc or doughnut shaped)
  • copper tape (wire can be substituted, approximately 15 cm long)
  • 1 AA battery

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Take your battery, place it close to an edge of the board, and center it. Mark its ends with the pencil to use as a reference point when gluing down the safety pins later.

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Here’s your board with the marks. Now we need to bend the safety pins.

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Using 1 or 2 pliers, take a safety pin, and bend it at a 90 degree angle at its middle. Using 2 pliers isn’t mandatory, however, it does decrease the chances of getting accidentally poked by a stray safety pin.

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90 degree goodness.

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Repeat the bending for all 4 safety pins, and line them up for a nice photo for your blog:

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Next, we will glue down two safety pins to act as the battery holder. Going back to our board with the pencil markings, put a drop of hot glue approximately 1-2 cm behind one of the pencil markings.

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Put the safety pin in the glue, with the loop side in the air.

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Throw more hot glue on top to help hold it in place.

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Repeat for all 4 safety pins. The second set of safety pins can be glued in approximately the same position on the opposing edge to the battery holder, but as you will see in a moment, their spacing doesn’t need to be nearly as precise. These second two safety pins will act as your motor mount.

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Next, add a dollop of hot glue to one side of the magnet:

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Now place the magnet glue side down between the two motor mount safety pins:

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Now, I use copper tape because it is cheap, convenient, and I have access to it. You can substitute wire, or even tin foil, to make the electrical connections from the battery safety pins to the motor mount safety pins.

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Cut two thin strips of copper tape, and check they are long enough to reach between the safety pins (again, you can substitute wires or tinfoil).

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Once you are sure they will fit, remove the adhesive backing and wrap them around your safety pins, like so:

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Another angle. Nearly done.

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Now, add your battery. You might have to bend the safety pins to get the copper tape to touch the battery’s contacts. It is better to make these adjustments now before you add the moving part.

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Now, lets make our coil. You will need approximately 60 cm of enameled copper wire, a small diameter tube for your form (I used a glue stick tube) and a small piece of sandpaper.

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Take the wire, and start by leaving a 5 cm tail on one side, and then wrap it around the tube 10-12 times. You will be left with a long tail on the opposite side. You want the long tail.

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Be careful when taking the coil off the tube so it doesn’t unwind on you. Now wrap the short end 1-2 times around the coil to help hold it in place, and unwind the long end so it hangs off the wrapped side as well.

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Take the long end, and string it across the diameter of the coil, then wrap it around the opposite side, so it looks like this:

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Now, this is the trick that makes it all work. Hold the coil up, between your fingers, and rest one of the tails on the edge of a table. Take the sandpaper, and rub of the enamel off on one side of the tail. Rotate the coil so the other tail is facing the same direction, and take the sandpaper again, and rub off the enamel on the one side of the other tail. When you are done, both tails should have the enamel rubbed off the same side.

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Now you are ready to insert your coil. Cut the tails shorter if you have to in order for them to fit into the motor mount safety pins. The tails go into the loops. Give the coil a spin, and if you’re lucky, it will start on the first try. If it doesn’t start, don’t worry, there is a lot of fine tuning you can do to make it work better.

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Now, about that fine tuning: you should have a running motor once you insert the coil. You may have to squeeze the coil so it is oval-shaped in order to get it to fit over the magnet so it doesn’t touch (as I had to) or you may have to play with the battery to ensure a good electrical connection is being made (this is where having a multimeter would come in handy for debugging purposes). The other helpful thing to do is balance your coil so it spins easily and freely, ideally not favoring one side over the other. When you’re done, you’ll have a running motor!

 

Kids have the best ideas

Kids have the best ideas

The other day, as my kids were playing together upstairs, my youngest almost accidentally discovered how to slide down the stairs on his old crib mattress. The kids had made a fort of the entire second floor in our house, and used the crib mattress to block the stairs. When they were cleaning up, I discovered my youngest jumping on the crib mattress while it was perilously perched on the top step. For a split second, after I had realized the danger my son was in, I thought “Wow, that looks like it might be fun. Or dangerous. Or both.” Then I quickly shooed him away.

A few weeks later, while I was home alone, I decided to give the mattress slide a try. I decided to record my first attempt in case evidence was needed to prove my death was due to my own stupidity. I thought I would share:

 

Simplifying my pull-back racer

Simplifying my pull-back racer

I wrote in a previous post about my first attempt at designing a pull-back racer. Being the over-engineered design it was, I took a shot at simplifying it for use in workshops and educational purposes.

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I removed the vast majority of the pressure-fit components, and reduced them to 3. It isn’t nearly as elegant to the eye, but it is far easier for kids to assemble. There is the base that holds the elastic in place, and the sides to hold the axles.

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I went with skewers for the axles, and the wheels can be laser cut as well, or cut from dowel. In the pictures below, they are laser cut.

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Overall assembly is pretty straightforward: push the sides onto the base, slide the axles through the holes in the sides, add the wheels, and strap on the elastic. The elastic then needs to be taped to the rear axle so it can wind up around it and provide the drive for the car. The rear wheels, ideally, should pressure-fit onto the axle as well, but often they don’t, and this is a trade-off for using skewers. Skewers tend to vary in diameter significantly, so while sometimes they will pressure-fit well, other skewers from the same pack may be way too small. It is nothing a little bit of masking tape can’t fix.

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Different sized wheels can also be cut and swapped out so kids can experiment with the effect of wheel size on the car. You can also add elastics around the outside of the wheels, or tape, or foam tape, to experiment with the effect of friction on the car’s wheels and its overall performance.

I have been working on removing the elastic and replacing it with a 3D printed spring, so that kids can be exposed to differing kinds of modern manufacturing (additive manufacturing with 3D printing and subtractive manufacturing with laser cutting). This will also remove another fiddly bit to the project: taping the elastic to the rear axle. It doesn’t always work out on the first try, not that is a bad thing, it’s good to have a deliberate failure point in a project so you can create a learning opportunity out of it, but sometimes, due to circumstances, having a fail-proof project is beneficial as well.

 

Designing a pull-back racer

Designing a pull-back racer

I recently offered a workshop at WPL for kids where we made wind-up, or pull-back, racers. Instead of the standard cardboard bodies, which in testing I felt bent far too easily, I opted to quickly design and laser-cut some basic frames made out of 6mm MDF the kids could attach their parts onto.

This led me to thinking: could I design a whole pull-back racer, save for the elastic, to be cut on one sheet of MDF?

After some internet sleuthing for ideas, I did see one, similar example to what I had in mind, and with that as a source of inspiration, I fired up Inkscape and went to work designing.

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After designing, I needed a quick trip to Kwartzlab for 20 minutes on the laser cutter to cut the design, and move closer to turning my idea into reality. I dry-fitted the components, and it started to look like a car.

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30 minutes of gluing later, and I had a fully-functioning pull-back car. My design is far from perfect: the rear wheels wander too much due to me over-worrying about tolerances, and the car is probably 2-3 times larger than it needs to be, but it feels solid and reliably works. See for yourself:

One thing I did learn, and will try to apply to the next time I offer this activity to kids, is the friction between the wheels and the floor is very important. In the video above you can see I wrapped one of the wheels in an elastic to increase friction. Otherwise, the car wasted too much energy spinning its wheels and didn’t go too far. I think cheap, adhesive-backed craft foam might be an effective and economical solution to that problem.

I am going to try a new design that balances between the cheapness of the crafty cardboard designs and my over-engineered single-sheet MDF one. A basic body, with side supports for skewer axles, and large wheels, all laser cut.

Organizing the Waterloo Mini Maker Faire

Organizing the Waterloo Mini Maker Faire

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June 15 at Kitchener City Hall, a large group of folks (including myself) organized and ran the region’s first ever Maker Faire, the Waterloo Mini Maker Faire. For those of you unaware of the Maker Faire phenomena, they are basically large, creative, do-it-yourself festivals, where folks come together to show off their creations, share their passion for their hobbies and interests, and for some, to sell things and make some money. A quick Google image search shows just how crazy and imaginative Maker Faires can be.

Aside from the generosity and support received from the sponsors, volunteers, makers, and general public, the other thing that blows me away was that all of this started as a result of a tweet I sent out a year ago today:

From that tweet, and in less than a year, myself, many of the hardworking folks at Kwartzlab, Diyode, and many other individuals from the #kwawesome community came together and pulled off a Maker Faire.

We had almost 50 tables as well as talks, workshops, demonstrations and live music. We had press coverage from The Record, The Kitchener Post, CBC KW, CTV News, to name a few. We had politicians come out and tour. Most importantly, we had 4-5,000 members of our amazing community come to Kitchener City Hall to tour the Maker Faire and interact with the exhibits.

Organizing it was a tiring, sometimes frustrating, but ultimately exhilarating experience. And I am crazy enough to try and do it again next year, but with two caveats: it will be bigger and better.

My favourite homemade salsa recipe

My favourite homemade salsa recipe

Once upon a time, back when my wife and I lived on our own together, we used to cook a lot. Not that we don’t cook a lot now, but back then we took courses to expand our abilities and tried new things. Today, due to having three young kids, our cooking is usually on the simple, “kid-friendly” side of the spectrum.

Back then, I once tried to make my own salsa. I found a recipe on the internet that sounded good enough so I made it. Uninitiated in the use of jalapeños in cooking, my first mistake was touching my eyes while coring the jalapeños. After crying for two hours, during which I finished making the recipe, I got desperate and I went to the internet for advice and decided to pour milk in my eyes. My second mistake was adding the dozen cored jalapeños uncooked to the salsa. I know now that cooking jalapeños is kind of key to controlling the hotness of the salsa. Regardless of whether you like your salsa hot or not, you should cook the jalapeños at least a little bit, otherwise you will pay for it not only when you eat it, but… later as well.

One day, after regaling her co-workers about my salsa-making exploits, my wife stumbled upon this homemade salsa recipe, shared with her by a co-worker. This recipe has become a staple in our household. When we finish eating the last batch made, we make another. It’s become a condiment in our house, both my wife and I can’t eat eggs anymore without adding this to them. It’s addictive, and I gave it out as gifts this past Christmas season. In the past year alone, I’ve made about 30 litres of the stuff. And, I am a pro at canning now, too.

So now, here is my favourite, addictive-as-crack salsa recipe:

Saute for 15-30 minutes:

  • 1/2 cup olive oil
  • 2 cups chopped peppers (use green, red, orange and yellow peppers, it makes it look really fun)
  • 4 cups chopped onion
  • 16 jalapeño deseeded and chopped
  • 4 bulbs garlic finely chopped (that’s right! 4 whole bulbs! the most time-consuming part of this recipe is peeling all the individual cloves)

Add, cook and cover ~ 1hr:

  • 14 chopped/peeled tomatoes (we do not peel the tomatoes!)
  • 1 1/2 cups vinegar
  • 2 small cans tomato paste
  • 3 tbsp coarse salt (kosher is the only way to go)
  • 1 bunch chopped cilantro ~1 cup (we often skip this one)

The length of time you cook the salsa will affect its hotness. Cooking for the full times shown above will result in mild salsa, and shortening the cooking time just a bit (to 45 minutes instead of an hour) will get you medium heat.

Makes about 3.5 to 4 L depending volume of tomatoes

Neat Engineering Competition

Neat Engineering Competition

Working at the University of Waterloo affords me some pretty neat opportunities. One of them is being able to occasionally view student project competitions for the Faculty of Engineering. This one I was interested in because I replied to a late-night plea for an ultrasound sensor that went out to the Kwartzlab mailing list. I guess a student group making a self-navigating boat damaged their ultrasound sensor and needed a spare for a competition the following day, and I happened to have one I could spare. After hearing the details of the competition, I decided to go have a look:

It was a fairly simple setup and the boats weren’t overly complicated. They used polystyrene insulation for the hull, a servo to steer, a drive motor for the propeller, usually three ultrasound sensors for wall detection, and many had arduinos for the brains. It is amazing what sort of complicated behaviours you can see emerge from such a simple physical/electrical setup.

Harmony Lunch

Harmony Lunch

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This past weekend I took my son to Harmony Lunch for the first time. He had a playdate who bailed on him and I decided to do something nice with him to cheer him up.

Suffice to say, I love that restaurant. From the pork burgers, to the weathered, contoured hardwood floors, to the still-functioning shake machine right out of the 50’s, to how you stink like grease and hamburgers when you leave, everything about that place is comforting to me.

As I sat beside my son, eating, we talked about how others can let you down, how to be strong, and how sometimes it is important to sometimes take the time to do something that makes you happy. Our conversation drifted to other things, and I told him about how the restaurant was his Great-great-Uncle’s favourite restaurant. Apparently it is now his favourite restaurant, too. He suggested we bring mom there for lunch on Mother’s Day.

With his little brother still a crawler the thought of taking the whole family there, with Isaac shuffling around on those floors, makes my skin crawl. Still, it warms my heart to think that there may be a new tradition started on that Saturday afternoon.

My own CNC mill – Shapeoko construction so far

My own CNC mill – Shapeoko construction so far

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I consider myself a Maker, and have been looking to expand the tool set that I have available to create projects at home. One of my main focuses was to put together a small CNC mill. Ideally, a mill good enough for small wood/hardboard projects that I could also re-purpose as a circuit mill. The Shapeoko seemed to fit that bill.

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A little while ago I purchased the Shapeoko mechanical kit. I eagerly tore it open, impressed with the packaging it was shipped in. I spent a few evenings meticulously assembling it, and soon got distracted by other projects around the house. The past few evenings, I have felt a strong push to finish the project.

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The instructions are admittedly a little vague, but not too bad if you are comfortable making some assumptions. This is a credit to the design of the Shapeoko: it is designed well enough that it is hard to screw up the assembly. Tapping the few holes that needed to be tapped was probably the least enjoyable part of the experience so far. It became a little tiresome as it relied upon more endurance in my forearm muscles than what I already have.

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Overall, assembly is relatively quick and straightforward. I am curious as to how it will operate once complete. The kit itself isn’t designed with any sort of end stop sensors, so I bet there is a lot of focus on proper set up and hope that the project won’t overrun the physical limits of the mill. I am hoping it’ll be fully operational with a few test runs under it’s belt by the end of the weekend.

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Then, on to my Prusa.

KW Awesome Foundation

KW Awesome Foundation

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So for almost a year now I have been involved with the Kitchener-Waterloo chapter of the Awesome Foundation. I love it. I love every part of it. It can be stressful, difficult to find time for, and at times calls for a lot of effort, but it is worth it.

The Awesome Foundation is a random collection of 10 folks who get together once a month to pool $100 each to give away $1000 to local projects for which the money would make a huge impact in their community. Chapters are popping up all around the world. As of writing, officially there are 64 chapters in 12 countries, with over $380,000 given away worldwide so far.

I am a Co-Conspirator with Gabrielle Clermont, or what the larger Awesome Foundation would call a Dean. We basically pull the whole thing together. We find 10 people willing to give away $100 each to upcoming projects. We book a location to host us, solicit pitches and organize it so that everyone shows up and the money gets given away.

I’ve learned a lot about how the how charitable process works behind the scenes, and have gained an understanding as to why things can seem bureaucratic sometimes. The Awesome Foundation is pretty much the opposite of bureaucracy; it is a very loosely organized group of folks who do things very differently from chapter to chapter. Here in KW, we only give the money away every second month, have a $200 “People’s Choice” award if there are enough trustees that month, and we are big on having the Pitch Night to vet projects. Other cities operate entirely independently, for example, some chapter have Pitch Nights, others use only the content a web form only to decide who receives the money. Networking to find trustees to generously give away their own money, being thankful for any help received and maintaining those relationships, no matter how small, and always talking with others about the cool ideas in your head are a few of the things I’ve learned.

As the Foundation grows, both the bigger Awesome Foundation as well as our chapter here in KW, there has to be some change as well. Bureaucracy is creeping in. We’re working toward being more professional, advertizing more, doing press releases, and reaching out to people to encourage them to apply.

Personally, I’ve also designed posters, business cards, and I’ve even silk-screened t-shirts for the foundation. I spent a day last week distributing posters and just talking to random strangers about their cool ideas that could make our community even greater.

However, the best part of the Foundation are the people. The Trustees are some of the coolest people I’ve had the opportunity to work with. And the projects! I love them all. Even the ones who don’t get the grant are all awesome. When deciding that month’s prize winner we often have several we’d love to give the money to and there’s never been a clear winner.

Also, I tend to try to support anyone who pitches. My social calendar is basically dictated by the Awesome Foundation. I’ll volunteer for projects that need help or go to the shows and performances of the artists who pitch. That, in a nutshell, is what made me fall in love with the Foundation. I have met so many amazing people in this community and done and seen so much since I started putting more into it a year ago. The Awesome Foundation has made me a better, happier, more engaged person.