Solar Energy with Kids

Back in 1970, thanks to the Whole Earth Catalog, I  discovered Farrington Daniel’s book Direct Use Of the Sun’s Energy which was first published in 1964. It not only recounted solar energy history  about turn of the century hot water heaters and distillation plants, but told how to make solar ovens, cookers and hot water heaters.  I was worried about the greenhouse effect  so it captured my imagination.  I remember running down to the thrift store to buy an umbrella in July. I lined it with aluminum foil, chopped off the handle, made a stand for a cup and, voila! a cup of almost boiling water for tea. I made a fresnel lens focusing collector for heating water. It was great. 

  

    As time went on I built a beer can solar collector for my shop and made a solar water heater by painting and old hot water tank black. We bought a house with big south facing windows and probably get 20-25% of our heat from the sun by just opening the curtains. If only gas had gone to $ 2.50 a gallon.

   I stayed at least peripherally interested in solar energy but along about the middle 80’s I noticed my friends’ eyes beginning to glaze over any time the subject was brought up. I felt like the  crazy uncle gone round the bend with impractical schemes.

   One morning I woke up and realized I’d been talking about solar energy for almost 15 years and hadn’t really done much with it. I was working with kids doing science and carpentry and it occurred to me that they might be interested. At least I could make a demonstration project. So I built a solar hot dog cooker. Not exactly practical, but the kids loved it. I was amazed at their reaction: no glazed eyes, no chuckles about impracticality, just amazement and wonder, my feelings still. To make a long story short, the kids’ reaction motivated me to make more equipment to demonstrate solar energy and  what evolved was a 2 hour solar energy presentation for a classroom of kids. The following is a description of my gear in the order of presentation:

1.  A sundial. Clamp it to the table so it won’t move. Inside with the lights turned down move a light past the sundial to illustrated how the shadow moves as the sun moves.   Introduces the concept that the sun moves through the southern sky in winter. 

To do:  - Check the time when you start and kids will come back and check it again later.

     - Copy the face of a sundial onto paper and the kids can make their own. 

2.  Black absorbs white reflects:

- Materials:   - Two pieces of copper,  about six inches square, one painted black, the other white.  If you have trouble finding copper or brass aluminum or steel will also get the point across. 

         - Digital thermometer is nice but not necessary

             To do:  - When you set these in the sun kids easily feel how much more heat black absorbs than white.  

               - Check the temperature difference with the thermometer. 

3. Two, 2 pound coffee cans each filled with water, one painted black,  the other white.  

To do:  -Same as #2 above 

4.  The hot water rises experiment:  This experiment shows what happens inside the pipes of a solar water heater. 

Materials:  - One clear plastic 1 gallon jar

           - 4 oz artichoke hearts jar:  drill two holes in the lid and glue in two pieces of  drinking straws in the holes so they stick out 1/4”  above and below the lid

            - food coloring

   To do:  Fill the big jar with cold water.  Fill the small jar with hot water (solar heated of course),  add food coloring to the hot water, put the lid on, and set the small jar inside the large jar.  The colored water being hotter, takes up more space than the same number of cold water molecules, and rises up, through a straw,  out of the little jar to the top of the cold water in the big jar. Like smoke coming out of a chimney.  

5.  Cardboard box heater. 

Materials: - shallow cardboard box with a lid, approximately 12” X 18”

         -  Flat black paint

         -  Piece of plastic sheeting or thin plexiglass, 10” X 16”

         -  Duct tape

         -  Digital thermometer

  This is a basic box heater. Cut a hole in the lid almost to the edges.  Use duct tape to fasten the plastic sheet over this hole.  Paint the inside of the box black.

           To do:   - Stick the thermometer inside the box. How hot does it get?  Mine approaches 200 degrees F.  

   - Cut a small hole in the end of the box and stick your fingers down inside.  Hot?    

   - Would painting the outside of the box increase the temperature inside the box? 

   - How could you make this heater work better? 

6.  A hot water heater: This is the combination of experiments 2, 4, and 5.  See Direct Use of the Sun’s Energy, chapter 6, for details of water heater construction.

Description:  A 2’ X 4’ box framed with 1” x 4”.  The back is 1/4”

plywood. The inside of the box is insulated with 1/2” foam board,  painted black with high temperature flat black paint and contains a framework of copper tubing (see drawing). The top of the box is covered with clear plastic. The top of the copper grid is connected to the top of a three gallon plastic paint pail. The bottom of the grid is connected to the bottom of the plastic paint bucket. The water  flows through the copper pipe, rising,  gaining heat, into the water tank. The cooler water settles to the bottom of the tank and then flows to the bottom of the collector. 

To do:  - Stick your hand in the water, carefully.  It’s hotter than you think.

    -  Look for the hot water where it comes out of the hose from the copper pipe. You will see it shimmer, like heat waves coming off hot pavement. 

- With a piece of surgical tubing and large syringe inject some water with food coloring in it into the tank drain that feeds  back to the  bottom of the collector.      .

-  Measure the temperature difference between the top and bottom of the tank.

- How could this water heater be made to work better?

- Comment on how inventions are often a combination two or three ideas known to most people        but put together in a clever and simple way.  In this case:  Black absorbs heat, hot water rises and a box with a clear lid combine to become a hot water heater.

7.  Solar heated kid warmer.  I built this for those chilly days in the fall and spring.  It really works and my preschool kids love it. It is just a big box heater.

Materials:   - Large cardboard dryer box

           - Duct tape

           - Flat black paint

   - 3” X 4” piece of visquine

Directions:  Cut a large hole in the side of a dryer box.  Cover this hole with plastic sheeting using duct tape around the edges.  In the opposite side from the window cut a small door.  Paint the box black and face towards the sun. 

      To do:  - Kids can hide inside this cozy space to warm up on chilly days.   

8. Make or buy a small solar oven.  I got a small cardboard oven (the sun spot) for $20.  There are good plans in the book Heaven’s Flame by Joseph Radabaugh.  You can buy more expensive ovens from Kansas Wind Power or Real Goods. 

To do:  - I always make cookies (even if they are small) and put them  in the oven before we start.

       - After the cookies are finished baking the kids can put their hands in the oven to feel the power of the sun. 

9.  Solar Hot Dog cooker (see plans below).  This is a parabola shaped frame that holds a plastic mirror.  The parabola focuses the sunlight on the hot dog and will burn it if the hot dog is not rotated.  The plastic mirror (available at glass stores) works a lot better than aluminum foil and it is easier to clean. 

To do:  - Have the kids two or three at a time put their hand at the focal point if they want to.  It is hot.

- Cut the hot dogs is half and let the kids cook their own.

10.  Umbrella lined with aluminum foil.

Materials:    - old umbrella

    - Aluminum foil

    - metal cup painted black

    - bailing wire, pliers

   Cut off the handle at the focal point and make a wire stand to hold a black cup.  Mine took about 15 minutes to heat a cup of water.

To do:  -  Put your hand quickly in and out of the focal point to feel the heat

-  Heat water for tea or hot chocolate

11.  Fresnel lens cooker. 

Materials:    - 1 X 6 Lumber

    -  Approximately 18 square feet of plastic mirror

    -  a stand to hold the cooking pot

    -  Pan painted black

   I made this from VITA plans. It is about 4’ in diameter and has four steps, each 6 1/2” wide, aimed a the focal point. It heats a quart of water to near boiling in 15-20 minutes. 

To do:     - Heat water for tea or hot chocolate

    - cook soup or rice

     -  Keep the collector aimed at the sun so the focal point will remain on the item being cooked

12.  Solar cells. This is an old 30 watt ARCO panel connected through a volt and ammeter to a rubber bladed 2 speed fan.

To do:  -  This is a good demonstration to teach that blocking the sun blocks the energy.  People often stand in front of the cells and ask  why they don’t work.

- Use the fan for air conditioning

-  Hook up another electrical device, a pump, motor or light   

13.  An old war surplus hand crank generator. This machine will put out about 50 watts, but it is hard to keep up for long.

To Do:  -Kids crank to see how many watts they can produce and  compare their output to the output of the solar cells.

14.  Books, magazines and plans:  Direct use of the Sun’s Energy, Heaven’s Flame, The 12 Volt Bible for Boats, The latest Popular Science on solar cells and power plants,   plans for a solar furnace made from beer cans and other miscellaneous stuff from my solar file. 

Here is how I make my presentation:

   Set all my equipment outside in the sun in the order they are to be presented.  Put cookie dough in the solar oven.  Go into the class room with the hot dog cooker, sundial and the two copper plates.  I’ll talk to them for about 5-10 minutes and try to cover the following points:

- Use of solar energy is not new

- Native American Pueblos

- Greeks, Archimedes setting ships afire

-Water distillation in South America 1890’s

- cloths line or sun coming in a south facing window

- There is a lot of power in the energy of the sun, 1000 watts/ square yard

-  Kinds of energy, coal, gas, hydro, nuclear pollute, solar does not except in the manufacturing process

- Will be important in the future, during their lives because of greenhouse effect

- Many uses of solar energy are very simple

-Based on fact black absorbs heat and white reflects it

-  Safety:  -Be careful of the hot water, it is hot

          - The focal paints are hot, test carefully

  I demonstrate the use of a sundial by turning out the classroom lights and moving a light past the sundial.  Kids can see the shadow move. 

   Outside I explain each demonstration in order asking for questions after each one. After we’ve worked through all the demonstrations they get 1/2 hour or so to check out things on their own. We take the cookies out of the oven and pass them around. Then we have our race between the solar cells and the hand crank generator.   This involves a short explanation of volts X amps = watts. Then inside for questions and answers.  This is the best part and the kids never cease to amaze me with their questions and  avid interest. 

I guarantee this demonstration will get kids excited about solar energy. There are several directions for follow-up activities:  Explanation  of heat energy vs electrical energy, writing about the history of solar energy,  making their own solar oven or cooker,  use of math to figure out how many solar cell you would need to supply their classroom lights, study and use of  low voltage electricity, or making model solar powered boats or cars,  to name a few.

  

A note of caution:  The power of the sun can start fires. Collectors should be used only under the direct supervision of a knowledgeable adult.  I once left my solar hot dog cooker unattended under  shed roof, protected, I thought, from the rays of the sun.  The sun dropped low in the sky and snuck in under the roof and over the end of the collector.   The focal point became a beam of wood six feet above the collector.  I did not think this was possible but, it was, and if someone hand not been around to smell the smoke the building could have burned down. 

Mechanical Puzzles

The Faucet, the Lock and the Lawn mower engine and more

   The kids in my summer class loved to take apart VCR’s, record players and typewriters, but I didn’t want them to come away with the idea that you only took things apart. I began looking for simple mechanical devices kids could take apart, see how they worked, and then put back together. Then the obvious occurred to me:  how alike puzzles and mechanical things are. Many people like puzzles but are intimidated by machinery. I had never liked puzzles, yet I liked to work on machinery.  Ironic.  Weren’t they really similar? Why not use real mechanical objects as puzzles to expose kids to simple machinery?  Maybe then they would be less intimidated by leaky faucets and machinery when they were older. Their puzzle knowledge could have practical applications.  

The Faucet

 

       At the hardware store I choose an eight piece brass gate valve, or faucet, about 8” tall. Kids like the feel and size of it. Smaller faucets don’t have the same attraction. They like to turn the handle and watch the gate inside the faucet open and close. I took this faucet apart and traced each piece, in the order it came apart, on a piece of felt.   The activity was for children to take the faucet apart, match the pieces to the proper shapes on the felt and then put it back together. After they could reassemble the faucet using the felt, I had them put the felt away and try again still arranging the pieces in order as they came apart. This is a good lesson when taking anything apart: arrange the parts in order as

they come apart. After kids can assemble the facet without the felt I’ll sometimes  challenged them to mix the pieces up and try again. If they need help they can always go back to the felt.    

The most interesting reaction to the faucet puzzle, however, came from a teacher. I had volunteered to take my puzzle collection, some folk toys, and some science equipment to a friends classroom. I spread everything out and let the kids choose their own work. The faucet was on one table and the teacher asked what you did with it. First I showed how the gate opens when the handle is turned and then I told her it was to take apart and put together. So she did.  She was excited and exclaimed to the kids around her “look at this, see how it works!” She was lost in the mechanics of a faucet. The principal came in. Julie, the teacher, said, “Rob come over here and see this.” Rob had other things on his mind and wasn’t really interested but Julie made him come over and listen to her explain how a faucet worked. While we don’t all get that excited about faucets, by merely taking apart and reassembling the faucet Julie was able to make a small part of the mechanical world less intimidating.  

The Door Lock

At a garage sale I found a flat square door lock from an old house. I cleaned it up and replaced one side with a piece of Plexiglas so the inner lock mechanism was visible. It was hard not to appreciate how the parts fit together and worked.  What happens when the door knob is turned and released?  How does this open the door?  How does the lock part work?  Why will one key work and not another?

  Back in class I set the lock on the table with some other science things to see if anyone was interested.  To my surprise no one was. I didn’t understand why until I realized kids didn’t see the individual lock pieces. It was all one unit to them. I took the lock home and painted the inside white and each working piece a different color.   Then I set the lock in a mini-door frame. What a difference! Everyone was interested and amazed.  Parents would ohs and ahs and the kids would sit down and work with it till the lock opened and they could understand how it worked. Some could even pick the lock with a paper clip. 

The Lawn mower engine

At the Smithsonian Institution I had seen a motor cycle engine with part of the engine block and cylinder head cutaway so the piston, crankshaft and valves could be seen. I thought it might be interesting to take this exhibit a step further by having an engine kids could actually take apart an put back together. I found an engine, disassembled it and steam cleaned the parts at a car wash. I cut a wedge shaped piece from the engine block to make the piston visible and removed a matching piece from the cylinder head. I removed another piece from the lower engine block to expose the crankshaft., painted some of the parts and reassembled the engine. 

My son’s teacher found five interested kids and we went to the cafeteria to test this creation. They really liked to take it apart but when it came to putting it back  together they weren’t very interested. I found myself getting upset because they were losing pieces and didn’t want to listen when I expounded on how a internal combustion engine works. 

       I did this same thing several times with different kids and each time came away feeling mildly irritated at the kids and being worried about losing pieces. I thought about this for a while and realized I wanted the kids to completely take and engine apart, put it back together, and understand how it works all in hour and a half. This was obviously, or I guess not so obviously, too much too expect. 

My new plan was to simplify the engine reducing it to basic parts and concentrate on the kid’s interests. I put away the carburetor, the ignition system, the flywheel, the pan and lots of nuts and bolts. Now I didn’t worry about losing parts.  Then I forgot my speech on how an internal combustion engine works. Maybe I’ll show how the valves pop up, or name a part or two but mostly I let them take it apart and put it back together.

This motor is now part of a puzzle collection that I take to schools and in any group of kids there will be several who want to take it apart and put it back together. It familiarizes children with motor pieces and plants the seed that motors are just 3-dimensional puzzles not some unfathomable mystery.

The Little Hammer with Nesting Screwdrivers

I saw a box of these little hammers at the hardware store and it reminded me that my father had given me one like it when I was young. I bought one for my own kids and they proceeded to take it apart and put it back together so many times I took it to my preschool shop class.

For younger kids I’ll take the hammer completely apart, laying the parts in a row, and reassemble it, working backwards, last piece first and first piece last. Laying each piece in order, in a row, is a habit that will keep parts organized when attempting more difficult projects like the faucet and the flashlight. Kids will often take the little hammer apart and put it back together several times. They especially like to show off reassembling it for Mom or Dad.

The Flashlight

Materials

•  A good quality flashlight that comes apart at both ends. It should have a plastic, not a glass, lens.

•  Batteries for the flashlight.

•  A piece of light-colored cloth (felt or canvas) big enough to hold all the flashlight pieces laid out in a row.

•  A small piece of sandpaper (220 grit) to lightly sand the ends of the batteries and/or contacts.

What to Do

Make a guide to keep the parts in their correct order as the flashlight is disassembled Take the flashlight apart and set the pieces in order as they come apart, on the cloth. Draw around each piece onto the cloth with a felt tip pen. The activity is for kids to take the flashlight apart, placing each piece on its corresponding shape on the cloth. Then the job is to reassemble the flashlight. The test is, does it work? Common mistakes are putting the batteries in backwards, not having the bulb in properly (be careful of the glass), and not having the threads together straight or tight.

As an added activity you can get a battery checker (electronics supply store) and have children make sure the batteries are OK before assembling the flashlight.

The Rube Goldberg Machine

  

       During my summer shop class kids would come to  me and say “I want to make something that really works.”  I wanted to help them but to make something that works from miscellaneous mechanical parts is  complicated.  Their imaginations were ahead of their capabilities. But maybe I could construct a machine to show what was possible, something to inspire kids and exercise their powers of imagination and observation. 

I combined the base of an old treadle sewing machine and a box of “good stuff” kids had collected from take-apart class into my version of a Rube Goldberg machine.  First I built a table top for the treadle apparatus and ran a shaft, supported by bearings, down its length.  This main shaft was connected by a leather belt to the large treadle operated pulley underneath the table.  Now the main shaft would turn when the treadle was operated.  From here it was just a matter of hooking different gizmos to the main shaft.   The machine changes every few months, but in it’s present state consists of the following:  two color wheels, several belt drives (big to little, little to big), a zoetrope (short movies), a saw which actually saws wood, a worm gear that pulls a bronze slug slowly across the table, a bicycle generator hooked to a light and switch, a small merry-go-round, a revolution counter, and a flag waver made from a bobbin winder. 

I’ve taken this contraption to preschools, schools, and child fairs. It usually takes the younger children  a short time to learn the rhythm of treadle use. After they get the hang of it they check out the color wheels, try different “movies”, turn on the light and try to follow how the other devices work. 

Besides being fun, this machine acquaints children with mechanical devices and presents elementary scientific theory in a non-threatening way. Perhaps most important in the day and age when nearly everything is manufactured it plants the idea that person can actually make something by themselves

The Busy Box

    My wife is an occupational therapist and worked with kids with special needs. She and a another teacher asked me to design a box with a bunch of different activities/hand movements. The pictures below show what we came up with. There is a ball roll which goes from the top corner box to a bottom box, A radio, a fan, a chain lock, slide latch, a lift latch, a light, a door lock with a key, a peek-a-boo box, and as you can see, the bells in the center.

This was actually the second box I built. After I built the first one I wondered if the kids would actually like and use it. They did. 25 years later they are still using it! If you decide to build one of these consult with the teacher/therapist who will be using it with kids to see what they want and what their specific kids need.

The Magnetic Marble Roll

(actually uses mini kiosh type balls)

     

     Years ago my son’s daycare moved. At their new location there was absolutely no playground equipment. I’d seen kids have a pretty good time on those small climbing domes and thought one could be built fairly easily from electrical conduit. I went ahead and built one and brought it to the playground. The reaction from the moms and kids was amazing. They acted like I’d built the Eiffel tower. This started me down the path of building things for kids and eventually to setting kids up to build themselves. Here are directions for the  marble roll and a bit about how the design evolved.

    A few years back I was teaching children’s carpentry and science and a friend lent me a small wooden marble roll to use in class. It consisted of two upright 1 X 4’s connected by sloping, grooved troughs. The marbles rolled down the troughs, reversing direction in a zigzag fashion, to the bottom. The kids loved it! They would roll one marble down by itself, then two or three, then a whole handful. Over and over and over again. They used it so much it began to bother me. What could they possibly be learning? 

Another friend mentioned that the Museum of Science and industry in Vancouver, B.C. hand a giant velcro ball roll. I went to take a look and discovered a large wall covered with velcro. Beside the wall was a box of small troughs made from plastic plumbing pipe split lengthwise. Each trough was fastened to a velcro backed L-bracket. The troughs could then be placed anywhere on the velcro wall. By moving the troughs around, an infinite number of paths could be made. Children could design and then build their own marble roll.  

I made a scaled down version with a 3’ X 5’ sheet of velcro. It worked fine at first but gradually the velcro sheet wore out and the troughs would fall off. What about using magnets instead of velcro? I replaced the big velcro sheet with a piece of sheet metal and the velcro on the back of the troughs with sheet magnet. This worked great and still works after ten years.

Children learn from what the adults around them do. If adults make things then children learn interesting, useful and even sometimes beautiful things can be made by people, not just purchased. The Magnetic marble roll is such a project. Kids can help  with construction sanding, drilling holes, and fastening the troughs to the backing boards. Best of all, from an adults point of view, once finished, the marble roll requires practically no supervision. You will not believe how much fun and learning take place. My admittedly biased opinion is that every school and children’s museum should have a magnetic marble roll.

TOOLS

•  An electric drill, battery powered is fine. A hand drill will work.

•  Drill bit: for the 12-32 1/2” bolts and for countersinking the bolt heads. The bit which drills the holes and countersinks and the same time make things easier.

•  Screwdriver bit for drill

•  Screw driver to match the bolt heads.

•  A vice to hold wood while cutting is nice but not absolutely necessary.

•  Hand saw. A bands saw will make cutting the pipe faster.

•  Metal file for filing the bolt ends smooth,

MATERIALS

The backing

• A piece of galvanized sheet metal about 3’ X 4” and a 3’ X 4’ piece of 3/8” plywood for backing the sheet metal. Because I really liked the idea of recycling, I also tried an old refrigerator door. It turn out the doors usually have a thin plastic or vinyl coating which makes the magnets not stick quite so well. It works, just not so well. Perhaps a little more magnet surface would compensate. Also, I could never find a paint hardy enough to hold up to the constant rubbing of the troughs so the door became all marked up from the constant rubbing of the magnets. 

• 1 X 2, about 14’, for trim to go around the edge of the plywood and cover up the galvanized metal edge which could be sharp.

• 1/2” ring nails (I used bronze boat nails) to fasten the sheet metal to the plywood board.

• short sheet rock screws  (16 or so) to fasten through the back of the plywood, through the sheet metal and into the trim.

• a 1 X 6 about 3 feet long (maybe a bit shorter), a 3” door hinge, and a 2’ piece of thin rope. These will be for a stand to keep the marble roll standing up.

The balls, pipe, troughs

•  First off, although I call this a marble roll, the name somehow stuck, but I never have kids use marbles. Marbles tend to roll all over and have to be chased down. Porcupine balls are the best because they roll slower and stay fairly close to the marble roll. Available from Oriental Trading company.

• 7’ of 2” white plastic plumbing pipe

• 2” plumbing pipe connectors: four 90˚, four 45˚, two tee’s, two sleeve connectors

• 75 1/2” 12-32 flat head bolts with nuts to fasten the pipe and pipe fittings to the boards.

• contact cement to glue the magnet sheet to the boards. The water base stuff works and isn’t so toxic.

•  3 1/2 or 4 square feet of magnetic sheets with adhesive backing cut into 1 1/2” strips. Get the heavy duty stuff as the light stuff doesn’t work so well.

•  eleven feet of 1/4” thick by 1 1/2” wide soft wood such as pine or cedar, for the wood pieces to mount the pipe troughs and connectors. These need to be flat, in order to accept the magnetic sheet, light so they’re not too heavy for the magnets, and of uniform thickness so the troughs will line up when mounted on the door. I just slice some pieces off a good cedar 2 X 4. I used plywood once but it warped.

•  A small box approximately 2” X 3” to catch the balls. This could be wood, cardboard, plastic or something fancier like a band saw box. It needs to be light. 

•  A box to hold all the pieces. I usually make a box about 5” wide by 3 1/2” high by 40” long. This box can sit right up next to the marble roll so if the marble roll is being rebuilt the troughs are more likely to be in the box and therefore less likely to get squished. A cardboard will work too, but they tend to get pushed out of the way.

•  100 grit sandpaper

CONSTRUCTION

Fasten the sheet metal to the plywood. with the 1/2” nails. Its probably easier to drill through the metal first. Just nail around the edge and then put the trim over the top of the

nails fastening through the back of the plywood into the trim with the short sheet rock screws.

PIPE

1. •Cut the pipe down the center lengthwise and then it cut into lengths: four 10” lengths and eight each of 6” and 8”. Although it is hard to hold, the pipe can be cut with a fine tooth hand saw. A band saw will do the job quickly. Sand the edges of the pipe smooth.
   

WOOD

• Cut the 1/4” thick wood into 1 1/2” strips. Cut it into lengths to match the  pipe lengths.  6” pieces for the 6” pipe, 8” lengths for the 8”, and 10’ pipe. Sand smooth.

*ASSEMBLY 

• Fasten the sanded split pipe to the wood pieces with the 1/2” bolts. I put the bolt head on the wood side. You must countersink it enough to keep the bolt head below the surface of the wood so the magnet sheet can be glued flat without a bump at the bolt. The nut goes on the pipe side. File the ends of the bolts flat if they stick through the wood. Two bolts to each pipe or fitting.

• Fasten pipe connector pieces to wood backing pieces in the same manner as above. File bolt ends flat if they protrude.

• Cut and fit magnet sheets for the wood on the back of each pipe piece (troughs and connectors). Apply contact cement to the back of each wood piece and after it dries remove the protective backing from the adhesive side of the magnetic sheet and fasten magnetic sheet to back of wood pieces.  

• Attach wood and magnetic sheet to the small box same as above.

TEST

Make sure all the troughs and pipe connectors fit flat on the  sheet metal. Then find some kids!

Mirror Steeror

(will have downloadable plans soon)

 

   Years ago a friend offered me a large pile of Plexiglas mirror rejects. At the time I was teaching a science and carpentry class for kids, so I was always looking for interesting materials. While turning possibilities over in my mind, I took two pieces (8" X 24") and fastened them, side by side, to a board so that one curved in, the other out.

The kids got a kick out of this. They could see their faces in weird shapes, which was good for a laugh, but still left me wondering: could I design it so kids controlled the mirror curvature? How about making it large enough so a child could see her whole body?

     In my basement workshop I had a cache of old boat parts, among them a steering gear. Maybe I could use it as a controller for this gizmo. I just needed to figure out how to combine it with a large piece of bendable plastic mirror. I made a frame to hold the mirror first, fastening the bottom of the mirror securely and letting the top slide up and down, between two small boards, as the middle of the mirror bulged in or out. It actually worked well this way. One person could stand behind the mirror and move it in or out while a friend, standing in front of the mirror, gained or lost weight rapidly!

    Next, I bolted my steering gear to a small 2 X 4 and clamped it to the stand, moving it around until I could envision a mechanism to connect the mirror to the steering apparatus. I had to experiment with the lengths and positions of the connector arms to get the mirror to move about 8" (at the middle) as the steering wheel moved through 5 1/2 turns. I worked these details out, and set it up by our front door. It passed this test with flying colors as we received many comments about the crazy contraption on the front porch.

    It is interesting to watch when someone sees the mirror steeror for the first time. Kids will go right up to it and turn the wheel. It doesn't take them long to see what happens. Adults are more leery. Pregnant women like it a lot.

   I've used the mirror steeror to break the ice on the first day of my summer shop class. It is amazing how interested kids can be when I start with something funny. I guarantee the smiles and the laughter will more than compensate for the cost and effort of building it.

    The mirror steeror has been displayed/used at the children's museum in Mt. Vernon, WA; at Mindport in Bellingham, WA; at the Target Gallery in Alexandria, VA (in 1993); at many schools in and around Bellingham, WA (in the 1990's); and on an occasional street corner for the entertainment of the builder.

I removed the door knob to make the lock easier to see.

This is the stand for the metal sheet that holds the troughs

Cross section of a pipe trough

The hot dog cooker in action. The bright spot is the hot dog.

My son Ben thought he was pretty clever to put his pet rat in the Busy Box I was working on