Torch

CARDBOARD today!!!!

I'm so excited I could scream.

One of unfortunate side-effects of my kids growing up is the decline of cardboard festivities around the house. So many of our cardboard creations in days gone by were inspired by my kids at play, or just wanting to build things with them with materials that were cheap (or free), and that could be manipulated by very little hands. Now that they’re older and so much busier with school and sports, we don’t get to play with cardboard nearly as much as we should. So I must find other ways to get my cardboard fix, and other kids to whom to introduce this miracle crafting material. 

This summer, for instance, I'm working on some craft projects with the kids at our church. Not all of these projects involved cardboard originally but I turned them into cardboard projects anyway. Because why not? Duh.

Now, one of these projects is a torch, which the preschoolers are making. 

Sometimes, preschoolers are relegated to crafts of the embellishment-only variety, because they’re younger, or because there is often a large group of them with not enough adult helpers to ensure everyone gets the help they need. This is very practical, by the way, as any one who’s had to facilitate a large group of young’uns in close proximity to colorful and messy craft supplies will attest to. But sometimes, people forget there’s cardboard. It's dreadfully tragic. Because cardboard levels out the playing field. And cardboard with simple electrics kicks up that playing field a notch. Whoo! 

The really interesting (at least to me) thing about today’s craft isn’t that it’s easy, or even that it involves batteries. I mainly want to share it for a very simple, no-glue technique that has many applications beyond this torch. 

First, let’s look at what we’re using to make the torch: a cardboard toilet roll and a battery-operated tea light. We want to somehow affix that tea-light to the top of the tube so it can shine out. 

Note that while the tea-light is small enough to fit within the tube, it’s too small to stay in place without falling all the way through to the bottom. 

We could stuff the tube with crushed paper, or glue a circle of cardboard close to the top to make a shallow chamber within which the tea-light can sit, like we did with Rapunzel’s Tower in this post.

Or we could use geometry and scissors. 

Here’s the geometry - first change the cross-sectional shape from a circle to a triangle by squishing the sides like so. 

The sides of the triangle now fit more snugly around the tea-light, albeit at the expense of newly-created hollow corners.  

BUT!

We're going to use those hollow corners in the next step.

Now come the aforementioned scissors. On each of the folds that creates a corner of the triangle, cut two slits a little deeper than the size of those hollow corners. Mine were about 1/2” deep and 1/2’ apart. To accommodate the height of the tea-light, I positioned the upper slit about 3/4” below the top edge of the cardboard tube. 

Push inward between the slits to invert the cardboard bit like so. 

Do this on all three sides.   

You’ve created little corner props, like shelf brackets.

Now the tea-light will sit on these little props, in its chamber, without falling down in the tube. It’s still not wedged-tight but this is exactly what we want, because we’re going to add the fake flame now.

We used yellow and orange cellophane paper but tissue paper and even thin sheer fabric like chiffon would work just as well. 

Scrunch up the cellophane around the tea-light (we switched the tea-light on first)  

and wedge it into the chamber.

Finished torch. No glue, no mess. And if an adult were to cut all the slits beforehand, as well as the pieces of cellophane paper, all the kids would need to do is push the little cardboard props inward, wrap the tea-light with the cellophane paper and stuff it into the top of the tube.  

Incidentally, to switch the light on and off, we just lifted the whole tea-light-cellophane bundle out of the chamber and flicked the switch through the cellophane paper (no need to unwrap).

If, however, you enjoy the higher risk levels associated with small children and glue, you could wrap the outside of the roll with decorative paper as an additional step. 

I found some wood-grain paper for this. 

Voila - wooden torch that actually works.

Can also be diversified to lighthouses, fake candles, night lights, castle turrets . . . and the push-in cardboard prop technique has even more applications wherever you need a quick shelf support!

Harry Potter Party: Ollivander's and the Science behind the Magic

This is the last of our Harry Potter party posts! I counted: 20, including this one. Twenty!

This one is less of a tutorial than a series of links to resources Emily used to re-create the "magical" effects of Ollivander's Wand Shop.

For your convenience, here is the Wand Shop video from our original party post:

Let's start with her MakeyMakey set, which I bought her some years ago. She's had a lot of fun with it, largely because it's such an open-ended tool for turning everyday objects into working circuits that do crazy things. Like turning a banana into a computer keypad. Yes, really. If you're not familiar with MakeyMakey, it's essentially a circuit board that makes it easy to connect anything that will conduct electricity (e.g. fruit, your own body, etc.) to a computer and/or the internet. 

Which sounds vague, so here's the example of the Ollivander's Wand Shop Sound Effects setup. The nuts and bolts are straightforward: there is a circuit board and a bunch of connecting wires. Emily created a kind of effects board from a piece of cardboard and aluminum foil,

on which each sound effect she wanted to create had its own terminal (a patch of aluminum foil) that was connected via a wire

to another terminal on the MakeyMakey circuit board, which then gets plugged into a computer that accesses the sound effects.

Then she used Scratch, which is a simple coding software that she learned to use in school, to write a program on that computer for her MakeyMakey setup. Here is the link to her code.

To work this thingamabob, you'd essentially have to make a complete circuit, using that computer (ours was a laptop), all those wires, and your body.  

Here is a short video Emily made to instruct the party volunteer helpers on how to work her setup. 

Summary: Apparently, there is no such thing as magic; magic is really Science. And Science is supreme (but not as supreme as cardboard, obviously).

Tinker Crate: DC Motor

Just before Christmas, I reviewed the Biomechanical Hand Tinker Crate. While corresponding with the good folks at Kiwi Crate, we got to talking about the way the subscription plan worked and the variety of themes and scope of projects potential customers could expect when signing up for this. To give me an idea of this diversity, they sent me three more kits, including two that were retired, so I  could share them with you.

This is the DC Motor Kit, which Emily worked on over the Christmas break.

Here's what came in it - electric components to make a classic DC Motor (and stand), along with some peripherals for fun applications.

The magazine (see first picture for cover) covered the theory and principles.

The blueprint sheet contained instructions for connecting this motor circuit.

Emily worked on it all by herself. I usually like to interfere because I'm nosy that way (and I can't keep my hands off anything Physics, really), but I sat out and let her do her own thing this time, just to see if an 11-year-old could set everything up without adult help.

Yes, she could.

Here's the completed DC motor (disconnected; if it were connected, that coil of red wire would be spinning).

Here are a couple of videos of the DC motor in action.

Kate came to watch us later, and used the supplied cardboard disks to turn the motor into a thaumatrope.

Tinker Crates are targeted at the 9-16 age group and our 11-year-old managed this one perfectly. Even our 7-year-old could make it spin (and be enthralled), although she would've required some adult assistance were she the one building it from the start.

Here it is in action:

If you've attempted a home-made a DC motor with your kids, you might remember the frustration of setting it all up and having it refuse to work, due to any number of issues: not enough turns of wire on the coil, a too-weak magnet, a wrongly-positioned magnetic field, an ineffective support for the axle, the wires not making good enough electrical contact, etc. 

I'm happy to say that this motor worked wonderfully, thanks to the Kiwi Crate team working out all the kinks beforehand and creating a simple and effective design for this circuit. While we want our kids to be problem-solvers and not shy away from obstacles to instant success, we also don't want them frustrated at the outset because of unsound theory, insufficient understanding, or poor engineering from the teaching end. It's lovely to have a kit like this that comes together as easily as a toy and inspires learning as solidly as an experiment. 

We have two more Tinker Crates to share with you. Check back soon!

Science Party: Fiber Optic Lamp

What's a Science Party without Physics, right?

To balance out all those other Chemistry experiments, Emily and I decided it would be fun to do a little electric circuitry. We also wanted to stage a fake dissection as a token Biology offering, but fabric frog innards were too time-consuming to sew, so we filed away that idea into the Maybe Another Party category of my brain. 

Before we settled on classic from-scratch circuitry, we considered the more trendy electric playthings now circulating the internet. Like electric playdough, for instance. We made it, it worked for us, but we couldn't see 16 kids "playing" with it and taking home something concrete at the end of the day to show for it. Also, the resistance of the playdough was so high that we'd need 9V batteries (instead of the usual 1.5V variety) and all kinds of safety and theory lesson bytes in order for the kids to fully get what was going on.  So those were - again - filed into the Maybe Another Party category, and I returned to basics. 

Just for info, electric circuitry is not the same is electronics. "Electric" is literally electricity flowing through a circuit and making light or sound or whatever. It can be low-current (e.g. batteries) or high-current (e.g the wiring of a house connected to the 110 V/220 V mains). Electronics involves logic and the circuit actually doing something clever (e.g. a robot vacuuming your floor when the dirt level gets high enough to set off a sensor, or turning on a sprinkler system at certain times of the day or when the humidity is low, or frying someone's head if they walk across a intruder-alert laser beam). The current involved in the actual  circuit is usually very small because it involves semiconductors which operate at the electron level, but electronic circuits can also be relayed to the mains to control regular high-current appliances. 

I like both, but I like electric circuitry more because I can see what's happening in the circuit. Electronics is cool and magic and high-tech and everything, but I can't see what the circuit is doing because it's all at the nano-level. Also, with IC boards and programmable gizmos like Arduinos and computers and whatnot, the circuit itself becomes a black box - we can use it without really knowing how exactly it works, only that it "does XYZ if you plug the green wire into the yellow socket". 

Over the summer, Emily, with all that sunshiney time on her hands, started to dabble in electronics and simple computer programming. (Someday I will write a post on our electronic toys [we love Makey-Makey and Little Bits!] and how we like them, and how to start your own electric/electronic stash for your kids to play with. But not today.) It was just toe-dipping, but she loved it, and while she was messing about in my tub of electric and electronic knick-knacks, we decided to make optic fiber lamps for her party. 

Lamps are electric circuits, but optic fiber lamps are more fun than regular light-bulb lamps, and we could pick colors and do light shows in the dark and all kinds of other cool things. 

Fancy on the outside but, at heart, a simple, basic electric circuit with a battery, wires and a thing that lights up. 

Some shopping had to be done first since, pack rat though I am, I don't usually keep enough stock at home for 16 optic fiber lamps. In summary, this is what we used for each lamp:

• Power Source
• Wires
• Light device (we used LEDs)
• Optic fiber bundle
• Switch
• Lamp shell (we used paper cups and cardboard)

Let's deconstruct each of those.

1 Power Source and Wires
First, we bought batteries. From Costco, which is Bulk Heaven. We needed a 3V (explanation later) power source, so we taped two batteries + to - as shown, with masking tape.

This is how to make a home-made battery pack. You'll need the taped batteries, a short, thick rubber band, two connecting wires and electrician's tape.

First, loop the end of one of the wires.

Lay it on one end of the battery pack, and tape it down with electrician's tape, stretching the tape to ensure a tight seal. Repeat with the other wire and the other end.

Loop the rubber band around the battery pack as shown. This compresses the batteries together and makes a tight connection.

Never, never connect the two free ends of the battery pack wires to EACH OTHER. This short circuits the batteries, which heat up and die. You can, however, now connect devices (we call them "loads" for the function they perform in a circuit) between the ends of those two wires, like this LED.

To prevent accidental touching during storage, we taped the ends with scotch tape until the party day. 

2 Light Device

You can use light bulbs like the kind found in traditional flashlights. We used LEDs because they were a lot brighter and also more colorful. I bought our LEDs from Radioshack, along with limiting resistors. 

Do not be frightened, people. It's quite layman. If you've worked with LEDs, you will have heard all the dire warnings to "always use a limiting resistor!!!!!" so as not to kill your sensitive LED. That is a good principle. Here's how LEDs work: they have something called a forward voltage. Different LEDs have different forward voltages. This means that if the potential difference (which is what a power source provides) is bigger than this forward voltage, the LED will turn on because a current flows through it. All you need is a combined battery voltage that is just a little bigger than the LED's forward voltage to work it.

The problem is that many LEDs have forward voltages that are either bigger than regular single 1.5 V Duracells but much smaller than 9V batteries. And there aren't any in-between battery values unless you are willing to buy battery holder packs or invest in lead-acid accumulators. And if you ignored the rules and put a huge 9V voltage across an LED with a forward voltage of, say, only 3.8V, you could fry the LED. I've done it - sometimes I don't save the packages my LEDs come in and I forget their forward voltage and I accidentally kill them when I next fiddle with them. So most people buy 9V batteries (because 1.5V batteries are too weak) and limiting resistors, which make the overall current smaller so it's still safe. See?

Or you could look for LEDs whose forward voltages are just about 3V, and use two 1.5V Duracells and be done with it.

Here's what I mean in pictures. Behold: the forward voltage on the packs - 3.0V. Most 1.5V batteries when brand new are about 1.6 V. Which means two batteries are 3.2V, which is more than the 3.0V forward voltage, which works. Hurrah!

This red one has a lower forward voltage (2.6V) , so I added a low-value resistor (that little brown peanut with stripes on it, taped to one of the legs of the LED) to it, to be safe. You can calculate resistor values on your own or you can google a resistor calculator like this and just plug the values in.

So, long story short: I wired up all the 16-different colored LEDs. Some required limiting resistors and some didn't. The LED leads (those pointy leg things) work perfectly left as is, but I needed to color-code them for easier connecting during the party, so I twisted their ends to connecting wires in blue and red, and taped them with electrician's tape. All will be made clear later.

3 Optic Fiber Bundle
The next stop was the optic fiber store. I've heard that you can, in a pinch, use fishing line, but it's not as good, and real optic fiber is not as expensive as you might think. I bought about 200 feet of .75 mm fiber for about $25, enough for about 20 lamps.

Then we made bundles of optic fibers - mine were about 7" long, and tied in bundles of about 20.

I used those infernal rainbow loom rubber bands that are littered all over our house - they are the perfect smallness for an optic fiber bundle. Also, I cut the end of the bundle (regular scissors work well) so they were flat.

And then I taped them to the top of an LED lens so they were in actual contact,

winding the tape all around to hold them together in place.

When you power it up, most of the light is transmitted to the tips of the fibers. Some light might "leak out" around the tape at the connection points, which is okay.

Here they all are, awaiting their transformation into lamps.

4 Switch
Switches are optional. But they are nice to have because they offer the option of turning the lamp off if you aren't using it. I've made a swing switch with a paperclip before, here, and today's touch-switch is just another variation. You'll need a strip of cardstock, a craft knife for making slits, and two brass paper fasteners.

Fold the strip into quarters, bent as shown, and insert the brass fasteners,

so that, when folded tight, you get a spring-loaded touch-switch. When you press the two halves together, the brass fastener heads will touch.

Open it out again and connect the ends of two free wires to each pair of fastener legs.

Like so, taped securely with electrician's tape.

We decorated our switches with washi tape, because white was boring.

Ta-da! Homemade switch.

Lots of home-made switches.

And finally, we have all the parts of a simple circuit - the switch, the battery pack and the optic fiber light. 

To make it easy to give instructions at the party, I color-coded the wires so that all I needed to say was, "Connect blue to blue, black-to-black and red-to-red", and with three twists, 

the entire circuit is connected, taking care of LED polarity (LEDs have a +/- direction, like batteries).

And this circuit lights the optic fibers when the switch is pressed closed. Easy! Even kindergarteners could do it.

However, this circuit does not make a lamp, and for that, we need a little cardboard help.

5 Lamp Body

First, we need a small paper cup with a radial-slit hole 

for the optic fiber bundle to poke through.

Next, we need a cardboard circle with a collar that is glued to its center.

The battery pack gets inserted into this, so it stands up.

Then we need a larger upside down paper cup, with a hole in its base for the other end of the battery pack, plus a slit for the wires to nest in. The cardboard circle with the collar is glued to the cup's opening - you can see the collar below the hole.

The battery pack is now slid into the top hole

and into the collared base (which is detached from the rim of the cup to show you the battery fitting into it). The battery pack is now held upright and in place by this collar and the top hole of the bigger paper cup.

Observe:

To insulate the twisted-end connections and prevent them from accidentally touching each other (and shorting the circuit), we tape over them - either with electrician's tape or regular scotch tape.

Then we push the wires through that slit in the bigger paper cup, pop the smaller cup on top of the bigger, tape them together, and the lamp is finished.

Press the switch to turn it on, and release it to turn it off. 

This kind of switch turns the lamp on only as long as it is held closed. To leave the lamp on without holding the switch, either slide a rubber band around the paper cup, pressing the switch closed, or wedge the switch in the slit where the wires are nestled.

On the day itself, we provided stickers and markers for the kids to decorate their lamps after they'd made them.

Some shots of the instructional diagrams I drew to help explain the different steps of the circuit-assembly.

And with that, Emily's Science Party posts are finished! I'll update the main party post with links to the various individual activity posts. 

Next up is a return to drafting! See you soon!