Mechanical propulsion question

Hi, Im trying to make a design of a mechanical device that will propel
a small cart along the ground for 5 metres, go up a sloped bank, stop
and roll back down to rest. The design is not aloud to envolve any
electrical or elastic components purely mechanical. I was just
wondering if anyone had any ideas on how i may come up with a concept
design. So far the only thing i can think of is to power a fly wheel
to a certain rpm then attach it some how with gears to the axle of the
cart. anyway I'm still thinking so suggestions would be appreciated.
cheers.
Reply to
Matt Baron
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You could put water in it which powers some sort of turbine which powers the axle. The amount of water correspounds with the distance you want it to go. This can also be replaced by a dead weight which falls, but then the height of the cart has to be bigger as the height of the slope.
If you need more power or speed, you can put a container with water under pressure, by putting pressurized air on top (the typical water rocket design), you would not need any mechanical design at all, just use the rocket effect.
When they don't exclude chemical energy, any form of chemical motor (diesel ...) can do. Just put some fireworks on the back, and set the thing off ....
Timothy
Reply to
Timothy
try a pulley and weight
what's my final grade?
Reply to
No Spam Man
compressed air water jet. Model aircraft " jetex ? " rocket. If an external tow was allowed, a falling weight. Model car gloplug or diesel engine. Model steam ( or compressed gas ) engine. If you can cross the start line at speed, an approach ramp. Put a sail on the cart, use a fan ( hand driven ? ). Train a mouse ( or other animal ) to pull it or gear a mouse treadmill to drive the wheels. have a sting loop down the course and wind it along from a pulley behind the start.
-- Jonathan
Barnes's theorem; for every foolproof device there is a fool greater than the proof.
To reply remove AT
Reply to
Jonathan Barnes
Use the energy equations and assume only 80% of the moving energy will be conserved.
In other words, you will need this much energy stored near or in the car to get the car moving with enough kinetic energy after five meters to get up the ramp this high ( where it stops at a height where it now has all potential energy).
Storing energy by mechanical springs uses the spring energy equation. By mass falling, potential energy converting to kinetic. By compressed gas, gas springs that give up less than 80% of what they had stored, etc. Coming back down is easy.
Reply to
Hobdbcgv
All these suggestions are good ones but in my first specification i forgot to say that to power the cart to start with we must use a variable power drill that will go up to 800 rpm. in the chuck a shaft is mounted with a rubber disc on the end of it. this is why i thought using a fly wheel may be the only solution as before the cart can be let go to run it must have no kinetic energy only potential.
Reply to
Matt Baron
What about a rubber band?
Matt Bar>
Reply to
Bruce Durdle
If you learn nothing else from the course, at least remember that incomplete specifications are a waste of everyone's time.
-Mike-
Reply to
Mike Halloran
In the precursor thread,
Maybe we should all agree not to respond to questions unless they're cast in terms of a formatted RFH - 1.) Background, 2.) Purpose, 3.) Scope, 4.) Constraints, 5.) Schedule, 6.) Terms. Make the correspondent think about the problem at least to the extent of forming a coherent question. Or maybe finding the answer him/herself.
"Background" should include the name of the course for which homework help is being requested, along with the name of the institution, and the email address of the teacher or professor. In case of really ignorant or stupid work-related questions, the name and email address of the correspondent's boss should be included.
"Constraints" should outline whether or not the First and/or Second Law must be observed. (If either or both can be suspended, the word "QUACK" must appear in the Subj. line to streamline inbox management.)
"Terms" could be omitted unless other than "Free."
"Schedule" could be omitted unless other than "Immediate."
It'd be kinda like self-moderation.
Fred "Jus' dreamin'" Klingener, PE (Ret.)
Reply to
Fred Klingener
Withholder!
You say, BUT in your first sentence, excluding the 'good ideas'. That's not the case. All of the ideas can be used AND powered by the drill. i.e. The Water Turbine. Use the drill to pump the water from a cart mounted tank near the bottom into an elevated tank. Remove the drill and the potential energy of the elevated water powers the turbine...
Reply to
Dan Bollinger
Use a coiled spring. It is not *elastic* and is mechanical. The electric drill will load it and the spring energy will propel the vehicle. When I was a kid that was the means of propelling my toys. "D" size "batteries" cost an enormous ten cents each. Jim Y, PE (retired)
Reply to
Jim Y

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