I'm currently building a jumping RC car. for the jump mechanism i consider using solenoids. they can produce alot of force and would seem to be simple to use on the mechanical side of things.

However im struggling to find anyone else using solenoids for this reason. or seeing them jump off there own stroke. i did find a video of someone using a car door lock solenoid and making it hop lightly on its own stroke and another video of a solenoid push an object very far. which gave me hope i could do that on a smaller scale for my purpose.

i have researched some physics and found that force alone doesn't exactly mean it can propel its self from the ground. but im not exactly sure what i should be looking at.

i apologies that this question is a bit half electrical and have physics. not particularly sure which one i should go to.

thank you for your time and any advice or direction you can give me in my research/project would be helpful.

  • 1
    \$\begingroup\$ I'd say this was first a physics question. Consider the weight of the car, how far forwards and upwards you need it to jump and how quickly you need to move the solenoid. Then consider the means of getting enough electrical energy into the solenoid to achieve that. Or just use good old trial and error. \$\endgroup\$ – Finbarr Nov 23 '17 at 12:58
  • \$\begingroup\$ Assuming that the car needs to jump 1 m into the air, the solenoid has to accelerate the car to 4.43 m/s upwards. With a suspension stroke of 0.1 m, your car has to accelerate at 98 m/s^2 for 45 ms. If the car has a mass of 4 kg, this means that the solenoid will draw an average of 872 W during the brief push against the ground. Now consider that this is assuming 100% efficiency: in reality the tires and shocks will rob some energy, and solenoids aren't very efficient. A more realistic 25% efficiency would mean 3.49 kW (equivalent to a 314 A burst from a 3 cell li-ion pack). I'd use pneumatics \$\endgroup\$ – jms Nov 23 '17 at 15:10
  • \$\begingroup\$ @jms thank you for the input. it was very helpful. the car its self is going to weigh less than 200 grams. i was considering pneumatic but i can find components that are small enough to fit in a compact little car. manly the reisavour/ tank to hold all the compress air in. currently im going with springs but would like something else. \$\endgroup\$ – ElQwerto Nov 24 '17 at 2:09
  • \$\begingroup\$ also what equations did you use to get those numbers. be very helpful later om. since i had trouble determining high from velocity and acceleration. \$\endgroup\$ – ElQwerto Nov 24 '17 at 2:11

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