Got to love it when a plan comes together

Got to love it when a plan comes together

On time and under budget to boot! Work tasked me with making five prize wheels. I estimated it’d cost $50 to do and got the go-ahead. Approximately it cost me:

  • $10 for the mdf to make the wheels
  • $6 for the dowel for the clicker
  • $10 for the hardware
  • $10 for the wood for the stands
  • Free! for the clicker (just a strip of plastic cut from a lettuce box)

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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. Read more

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. Read more

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: Read more

Another long weekend, another weekend challenge

Another long weekend, another weekend challenge

This long weekend, the project I’ve decided to try to accomplish is to cut and assemble an Iron Man helmet using the Pepakura technique.

Many of the more “professional” quality costumes you see at conventions are made using this technique. Basically, someone has modeled a costume using some modelling software (maybe something like Sketchup), and exported it to a program called Pepakura Designer. The Pepakura Designer software turns the 3-D model into a series of printouts broken up into pieces with cutting and folding instructions you use to cut and fold and glue the paper printouts into the 3-D object that was modeled. Read more

Balsa wood airplanes

Today, if you want to fly an airplane, its as easy as going to a store with a toy section, and buying one. There are so many shapes and styles available, made out of Styrofoam, or plastic, or wood, or fiberglass, many with all electric engine and controls.

Not too long ago if you wanted to fly an airplane, you built it yourself. Most frequently, you built it out of balsa wood, and flew it with a gas engine. You also wired up your own servos and made your own control surfaces. Suffice to say, a lot of knowledge was required, and a lot could go wrong along the way.

Naturally, building the airplane yourself took an enormous amount of time and effort for something that could easily be destroyed in a flaming inferno a few seconds into its first flight, or at any point during any flight, for that matter. The construction process itself was very similar to how airplanes were built during the world wars, just on a smaller scale. You have forms that give the plane its aerodynamic shape, and spars that run the length of the piece that old the forms in place, then skinned over to make the plane smooth.

Real-life Spitfire construction

Running a gasoline engine was equally difficult as they require a lot of maintenance to keep running properly and a lot of knowledge to even get them running at all.

But people did it. It was a labor of love. They still do, just not as frequently with all the cheap premade-all-in-a-box options out there.

I built a balsa wood airplane on the July long weekend. All in the span of the July long weekend. I did this as a personal challenge, inspired by my Grandfather.

We recently moved my Grandfather into a retirement home, and sold his house. A sad story in and of itself, but it was ultimately necessary and for the best. When cleaning out the house, some of my Grandfather’s possessions were divided up among the family, and one thing that many seemed to express interest in was an old balsa wood airplane my Grandfather made on a vacation at the old family cottage. It was covered in tissue and still looked good for something close to 50 years old. Unfortunately I didn’t get a photo of it, but it looked like an old Stearman biplane. I wanted it, all of the things I wanted from my Grandparent’s old place I wanted for sentimental reasons, and as a kid I could remember him showing it off to me and being so damn proud of the thing. But it ended up going to my cousin instead.

So, I decided the next best thing would be to make one myself.

I picked a simple, learn-to-build kit from Guillow’s. The Fly Boy model. I made it a personal challenge to build it in the span of the three-day, two-night long weekend.

Building the frame was probably the most satisfying part. Out of necessity, some of it has to be done in stages, but because you use either white glue or wood glue, the drying process is only a couple hours long, so several major steps can be accomplished in a single day. It becomes a very enjoyable day when you can say “I took some wood and turned it into something that looks like and airplane”. In reality, it was about 6 hours of effort to get the frame complete. For the wing, you take the ribs (the aerodynamically-shaped pieces that give the wing its lift), pin them on the plans vertically, then glue the spars onto them to hold everything in place, pinning them down as well to hold them tight. When dry, sand, and combine. The wing was made of 3 major sections, all of which could be built at the same time, and then later assembled when dry.

Skinning the airplane is definitely a far more finicky and slow process. This model required tissue paper and diluted white glue to skin it, painted once on the frame, then again to the surface of the tissue paper that was touching the frame to ensure the glue penetrated all the way through the tissue paper and into the balsa wood frame. Again, this was a very stepwise process, but due to the diluted nature of the glue, it took a long time for the tissue paper to dry. The really neat part was that once you were done skinning, and the tissue was dry, if there were any wrinkles left in the tissue, lightly misting them with water would remove them when the water dried up. It basically tightened and stretched the imperfections out of the tissue paper.

The wing was held in place by elastics and a dowel so you could move it forward and back to balance the airplane without having to commit to gluing it in place permanently. It also makes it easier to transport the airplane when you can take the big wing off.

Threading the elastic through was definitely a test of patience. I ended up using a stretched-out coat hanger to help.

For the first flight the instructions recommended  only 25 turns of the elastic for wind up.

Here’s the pitch! I think this was the exact point I realized that if it doesn’t work I may be left with a twisted pile of balsa wood, tissue, and a spinning propeller. And a weekend’s worth of wasted effort.

Didn’t go far the first time, but it did survive the decent to the ground. I was amazed at how hard it hit and yet survived, unscathed.

Later that day, when flying the airplane again, I lost count of the number of turns I had put into the propeller winding it up, and the elastic snapped. When it snapped, the elastic recoiled and spun around manically, tearing through the tissue paper. All of which was quickly and carefully cut out and replaced, which is pretty damn cool when you consider how easy it is to repair the airplane. So long as enough of it survives, it can always be fixed and re-flown, but it also served as a reminder of just how fragile flight can be. So remember, count your turns!