Flywheel Powered Car 2 (with clutch)
Started: 9/2/2025 Completed: 9/19/2025
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Objective: Improve upon first flywheel car to make it more useable, strong, and longer running. Below are the improvements I have made.
two counter-rotating flywheels to cancel out gyroscopic effects and double the amount of inertia.
Adjustable steering to set direction of car
Improved coupling for drill to transmit power through (to "charge" the flywheels)
Improved frame design is much stronger and also is modular so components can like transmission and front frame can be switched out
Flywheels mounted on metal shaft and high speed bearings for low resistance and high rigidity
Gearbox allows for a higher gear ratio, more steady speed, and longer run time
Software and Parts Used:
Onshape CAD software was used to 3d model and Assemble the parts
3D printer used to make PLA parts (Pictured in Blue)
Assortment of ball bearings used to minimize friction (Pictured in Grey)
Rubber was used on clutch for grip
M3 bolts and nuts used to fasten parts together (Pictured in Orange)
Spring was used to activate clutch
18mm Steel balls were used in flywheel to increase rotational inertia
8mm steel tube was used for a rigid and straight frame, flywheel shaft, and rear axel.
Results:
Final Product has very robust frame.
Gearbox with 1:16 ratio efficiently slows down the rotation of wheels and creates high torque. Currently for every four rotations of the flywheel, the wheels rotate once.
Counterrotating flywheels allows for stable drive since change in angular momentum and direction do not have adverse affects.
Steering works well and can be adjusted with the turn of a bolt.
Car moves about 25 feet upon release.
Problems:
Wheels lack traction so cars rear wheels spin resulting in lost power and change in direction. This was negated slightly by wrapping the wheels in duct tape but it is still not ideal.
Bevel Gear between flywheel is slightly inefficient and causes flywheels to slow when clutch not engaged
Cars flywheels just don't have enough inertia to move the car a significant distance. Each flywheel only has an inertia of about (1.18)10^-3 kg*ms^2, therefore when both are spinning at about 1000 rpm they only have about 12.9 joules of energy.
Challenges Overcome:
Planetary gearbox was inefficient since it slowed the flywheels twice as fast as current gearbox even with no load. This inefficiency is despite big gaps for gear backlash and ball bearings on every point of rotation
Flywheels would not tightly mesh with bevel gear. Bigger teeth were implemented to allow for more wiggle room, and the frame was made easily adjustable to fine tune gear mesh.
Future Flywheel Car Plans:
I have already started work on the third flywheel car. I will be solving the current problems like rubberizing the wheels, making a more efficient transmission, and implementing a solid steel flywheel with about 40 times the inertia. I will also be making the car remote control so the user can control the steering and operation of the clutch. These electronics will be run using the power from a generator getting its energy from the flywheel. I hope to have a run time of about 30-60 seconds, which is reasonable since the car should have over a kilo-joule of energy.
Video of car running will be here soon
Below is the past planetary gearbox that was scraped due to inefficiency
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