Introduction: K'Nex Sun Chimes


I was given a wind chime for Christmas, and very nice it is too. It has a varnished wooden case, and so it would be a shame to site it outside and let it suffer from the elements. It is not very windy indoors, though, and so the only way to hear it is to brush by it very closely, or jiggle the wind scoop (that's the wooden bit at the bottom).

The wind chimes came from a major supplier and details will be given on request, but the concept can be used for any comparable chimes. The chimes used have eight vertical rods inside which are struck by a threaded glass bead, attached to which is the wind scoop. They are 14" high from the top of the ring to the bottom of the wind scoop.

So why not create a device which does the jiggling? A nicer term for the wind chime is a jingle-jangle, and the wind scoop could be called a jogger, because it jogs the jingle-jangle.

This construction, built from Classic K'Nex, uses a flip-flop device to make the sounds, and so one might say that the falling flip-flops jiggle the jingle-jangle jogger. The sounds are very gentle, and the noise of the motor and gear train cannot be heard from another room, but the musical sounds can.

It is solar-powered, thus converting the wind chimes into sun chimes.

Of course, on a sunny day the device could be sited outdoors so that there was a double whammy of sun- and wind-driven sounds.

How It Works

A K'Nex solar motor is used to drive two gear trains, one to rotate the jingle-jangle, and one to turn the flip-flop assembly.

The eight flip-flops which jiggle the jogger vary slightly so that there is an element of randomness.

Each flip-flop falls when it overbalances and hits the side of the jingle-jangle causing it to swing lightly. Less than a second later, the flip-flop falls and jiggers the jingle-jangle jogger.

The flip-flop assembly contains two types of flip-flop, a red-connector-based one and a blue-rod-based one.

The red flip-flop will always strike the jingle-jangle jogger, but the blue one will often miss, striking only when the jogger is in the right position. This creates an element of randomness, just like the wind.

A K'Nex solar motor rotates at around 18 times per second in bright sunshine. Since there are seven blue gears (which have 14 teeth) in mesh with seven red gears (which have 34 teeth), the speed reduction is (14/34)^7 which is about 1/498, and so in full sunshine the flip-flop assembly rotates about once every 27½ seconds.

For the jingle-jangle rotation, there are three blue gears and three large yellow gears (which have 82 teeth), and so the speed reduction is (14/82)^3 which is about 1/201, resulting in a rotation speed of roughly once every 11 seconds in full sunshine.

Step 1: Make Sure You Have All the Pieces!

Have a look at the document here and set aside all the pieces specified. Like many K'Nex builds, it is quite hungry for its size on blue rods and 3D connectors.

Step 2: Make the Base

The very bottom of the device uses purple 3D connectors to form a flat base. The diagonal yellow rods add rigidity. Many K'Nex models are based on blue-rod-sided cubes, because the final structure tends to be strong. For added strength (not needed here), diagonal yellow rods can be added everywhere.

For the flip-flop assembly, the solar motor will drive a train of seven gears. Starting at the flip-flop end (which corresponds to the build sequence), these notes refer to them as 'gear set #1' to 'gear set #7'.

Build the base as shown. The right-hand yellow connector near the top left will hold gear set #1.

Step 3: Add Gear Set #1

This gear set will be on a 190mm black rod. It can be seen from the photo that the sequence of the components from the back of the device to the front is Silver Spacer, 2 Blue Spacers, Silver Spacer, Tan Clip, Red Gear, Silver Spacer, 2 Blue Spacers, Silver Spacer. Make sure that the tan clip engages the red gear!

Make sure that the black rod passes through the right-hand yellow connector of the three (looking from the front).

Step 4: Add Gear Set #2

This will be to the left of gear set #1, i.e. through the centre yellow connector.

Step 5: Add Gear Set #3

This is directly above gear set #2, through a white connector front and back. The second photo shows how these white connectors have been added (with the purple/blue connectors either side).

Gear sets #4 to #7 will all be directly above this gear set.

Step 6: Add Gear Set #4

This is above gear set #3. Notice how yellow and white connectors have been added to hold this new gear set.

Step 7: Add Gear Set #5

Again, this is above the previous gear set, and another layer of purple, blue and white connectors has been added. The second picture shows all the gear sets so far in place.

Step 8: Add Gear Set #6

We're getting towards the end of the flip-flop drive train now.

Another layer of yellow and white connectors has been added to hold gear train #6.

Step 9: Add Gear Set #7

Almost there!

Another layer of purple and white connectors holds gear set #7. The red gear will be driven by the solar motor.

The second photo shows all seven gear sets for the flip-flop device in place.

Step 10: Add the Solar Motor

Add two blue washes to the motor spindle, and then a captive blue gear with a tan clip. The solar motor is held tightly by the white connector. The open end of the motor spindle is not supported.

Make sure that, looking from the front, the solar motor's socket is on the bottom right so that the lead can easily be connected.

Step 11: Add Gear Set #8

We are now about to start on the jingle-jangle rotation gear train which will use three large yellow gears.

The second photo shows the front view.

Step 12: Add Gear Set #9

Build an extra layer as shown in the first photo, and then add gear set #9 as shown in the second photo.

The third photo shows the front view.

Step 13: Add Gear Set #10

Build another layer as in the first photo, and then the gear set as in the second photo.

The third photo shows the view from the front.

Step 14: Add the Wind Chime Support

Add the medium yellow gear and the section above it, as in the first photo.

Now add to the top as in the second photo.

Make the part of the support in the third photo and slide its blue connector into the purple one, as in the fourth photo, attaching the white rods as shown.

Add the red gear as shown in the fifth photo with the two-way grey connector holding it onto the yellow rod - it is this connector which will hold the jingle-jangle.

You will notice that the gears in the fifth photo are not quite in alignment. It would be more pleasing if the gears were level, but it is like this because I didn't want to shorten the jingle-jangle's string.

Step 15: Make the Flip-flop Core

Closely look at the photo.

There are two white 8-way connectors held together by eight blue rods.

On each rod is a blue spacer, three one-way grey connectors and another blue spacer.

Start by joining the white connectors with a single loaded blue rod.

Now add a rod next to the first one. Do not add the second rod somewhere else, because then you will end up adding more than one blue rod in a slot that has a rod either side, and it is very difficult to do this.

Work round adding each blue rod next to the previous one until there is just one slot left.

Make sure that all the one-way connectors have their open ends outwards otherwise you will end up undoing your work (which would be a finger-hurting exercise!).

Now comes the hard part - inserting the final blue rod. It is easy to slot a rod sideways into an unpopulated connector (because the sides flex a little), harder if an adjacent slot is already occupied and very difficult if both adjacent slots are occupied.

Unfortunately, for the last blue rod, both adjacent slots are occupied!

I used a vice to get the ends of the last blue rod in and I recommend that you do the same. If you haven't got a vice to hand, find someone with strong fingers and advise them to wear thick gloves!

Step 16: Make the Flip-flops and Add Them to the Core

The first photo shows the flip-flops. The actual design will depend on the jingle-jangle and how far away it is from the flip-flop core.

Add the flip-flops to the core in a fairly random manner. If you want more sounds, albeit more regularly, make the flip-flop contain eight red assemblies.

Step 17: Add the Flip-flop Assembly to the Black Rod

Put a silver spacer, two blue spacers, and then another silver spacer on the black rod, as shown in the photo, and then slide on the flip-flop assembly. Add a tan connector to fix the assembly to the rod.

You will notice in the photo that there are two white rods at the top right. These have been added to prevent the jingle-jangle from swinging too much (which causes too many flip-flop misses).

Step 18: Hang the Jingle-jangle

Hang the jingle-jangle on the 2-way grey connector underneath the jingle-jangle support.

Step 19: Make a Solar Panel Support

The precise design will depend where the solar panels are going to be sited.

I have some low windows and have made a small structure which will hold the panels just high enough, when standing on the floor, to catch the sun.

Two or more panels wired in parallel will provide that much more power in low light.

Now plug in the solar lead and wait for some sunshine!

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