Looking for something easier than trying to ride a bike with no handle bars?
A play on the spinner toy that has been in use for centuries, once used by Native American children and later adapted by colonial families, the contraption we have created is a large-scale version of the buzz saw or thread spinner toy. The size increases the danger, and the danger increases the fun. Two people can operate the spinner by each taking a handle, pulling the paracord until it is almost taut but not quite, winding up the cord on each side, and pulling in their perspective directions. The tire will then spin creating a whir and the LEDs will flash creating a pattern.
What: Giant Spinner Toy, also called Saw Blade
Concepts: Kinetic & potential energy, momentum
Time: 1 hour
Paracord, 30 feet
Bicycle rims and spokes
Large D ring hangers (model button to create spin)
Wood for handles
Apparatus to cut paracord and cardboard, scissors are suggested
Let's Get Spinning!
Step 1: Create a Model
In order to accurately make a giant spinner toy, it is necessary to understand how a spinner toy works and is used. To make a model get a piece of string at least 2 feet long and a piece of cardboard in at least a 5" by 5" square. Cut the cardboard into a circle and cut two holes in the center about a centimeter apart. Feed the string through one of the holes and back through the other, then tying the ends together to make a loop with the cardboard in the center. To use the model spinner, grab each sides of the loop, place the cardboard at center, and spin the cardboard and string like a jump rope, winding up both sides, and then pulling in opposite directions. This way the model spinner will unwind the string and have enough momentum to continue spinning and rewind the string in the opposite direction, continuing the cycle.
If this small model is not enough to understand the concepts of the spinner, try making a larger one with a cardboard piece the size of a small pizza, approximately 11" in diameter. This will make the final process of using a bicycle spoke as the spinner to be much easier to put together and make work effectively.
Step 2: Prepare the Bicycle Rims
Typically a bike comes in one piece, but for this project only the rims are needed. Before the spinner toy can be created, the rims need to come off the bike. This can be done by unscrewing the bolts on both sides of the fork holding the tire in place (If the bike is equipped with quick release tires then skip this step and remove tire after prying open quick release switches). Pry open the brakes from around the tire and remove tire from the frame of the bike (If your bike is equipped with disk brakes then ignore this step and remove tire from frame with ease). Decide whether or not to leave the tire on the spokes for the spinner, either way the project can be completed correctly. If the decision is made to remove the tire, make sure to begin by deflating the inter-tube by unscrewing the stem and using a flat head screw driver to press down on the stem and remove the air from the tire. Squeeze the tire all the way around the rim to remove any excess remaining air. Use a flat head screw driver or other prying tool to pry under the wheel rim and work around the rim, slowly removing the tire. Then after the rubber tread of the tire has been removed place it to the side and now begin removing the inter-tube and lining of the rim. Now you should be left with just the rim and the spokes and are now ready to begin assembling the toy spinner.
Step 3: Assemble Your Rim
A spinner toy, as is seen in step 1, has 2 holes in the center that the rope feeds through in order to cause the spinning as the rope winds and rewinds with the spinners momentum. A bicycle spoke has a bolt in the center, leaving the creation of a way to make these 2 holes to be necessary.
In order to do so, knock out the bolt-like center of the bike rims so that there is a hollow center.
Then, take D ring 2 hole hangers and zip tie them in place over the hollow center to mimic the center of the buzz saw toy that that has 2 holes cut into the middle where the string passes through.
Make sure that the D rings are put in place so that there are 2 holes that match on either side of the hollow space, making 4 holes total, with the paracord being able to pass through one and out the other easily without any tangling.
Step 4: Make the Handles
The paracord when run over skin can cause a great deal of friction and if the person operating the giant spinner toy is in pain or unable to get a good grip, the spinner toy will not be operated correctly. In order to combat this complication, adding handles on either end of the paracord will make the toy more comfortable.
Take two pieces of wood that are approximately 8" long and 3" in circumference.
Drill 2 holes into each of the wood pieces in the center, approximately 2 inches apart. These holes need to go all the way through the wood and come out the other side.
Once this is complete, the handles are ready to use.
Step 5: Feed the Paracord
Paracord will be utilized in the large scale spinner toy as string cannot hold the weight of the bicycle spokes. Take the bicycle spoke and the D ring 2 hole center, and feed the paracord through one of the 2 holes, as well as through one of the holes in the handle. Take the same end of the paracord and immediately feed it back through the other hole of the handle, making the cord take a sharp u-turn.
Take the side of the paracord that was just fed through the handle and pull it through the the other hole in the center of the bicycle spokes, in the opposite direction as the cord when through the first one.
At this point the cord should be in the shape of a hairpin, with a loop on one side where the handle is and an open end on the other.
Feed the opposite end of the paracord through the other hole in the center, and pull the spokes until it is in the center. Feed the open ends of the paracord through the other, unused handle and tie a knot to close the loop.
Step 6: Arrange the LEDs
To create a kinetic, or moving, art sculpture, the project needs some creativity. A pop of color can be added to a bike themed spinner toy by adding LED lights to the spokes. When the spinner is in motion the lights will create a pattern by spinning so fast that there seem to be a string of lights in the spokes, as opposed to a few LEDs arranged in whatever pattern is chosen.The LEDs can be put onto the rims be using zip ties and by appropriately arranging the loose "S" shapes of the LEDs to press the middle onto one of the spokes and the wings of the LED to push in the opposite direction against the neighboring spokes.
Step 7: Test the Giant Spinner Toy
Using a giant spinner is different than using the model spinners because a giant spinner requires 2-3 people to operate. A team of 2 should each grab a handle and keep the bicycle spoke between them, centered on the paracord loop. With slack in the cord the 2 people may toss the spokes like a jump rope causing the weight of the spokes to spin the 2 cords together into a twist on both sides. When the cord is twisted all the way, the 2 should pull away from each other, making the cord taught, and causing the spinner to undo its twist at a high speed. The momentum of the spokes will cause the cord to spin and twist again in the opposite direction, continuing the cycle. When the cords are twisted the pair should pull away from each other, and when the cord begins to unwind the pair should give slight slack.
If the giant spinner is not cooperating this easily, have a 3rd person join in on the fun and spin the cord taught. When the cord is twisted tightly the 3rd person shall let go and the pair holding the spinner toy shall proceed with keeping the momentum has coached above.
The spinner toy is also known as a Saw Blade because of the movement and noise that the spinner creates, but no worries, this is a safe buzz!
Step 8: The Spinner Toy & Physics
The traditional buzz saw toy that originated in native American and colonial culture was originally made out of bone and string and later wood. It had slits or gaps on the outer edge and when winded up and spun, it would create a "buzz" or a humming sound due to the interaction of the air with the divots in the wood or bone creating this whistling or buzz noise as the air glides of the spinning toy. With the bike tire however the outer surface is smooth and perfectly rounded so the sound isn't clearly heard as if the divots were in place. Also due to the fact that it takes 2 people to operate our spinner the amount of force required to pull increases. First the spinner must be winded up quite tightly increasing potential energy with every twist until it can be transferred into kinetic energy as it unwinds at an increasing speed. Also as the people pull as it is unwinding that creates more kinetic energy and as it winds back up and stops for a split second builds up more potential energy which is in turn transferred back to kinetic and the cycle continues between the transfer of energy until the people operating the toy decide to stop. Not all the potential energy is transferred to kinetic, some is lost to friction and a very small amount due to air resistance. That is the basics of the operation and physics of this giant toy spinner.