Need help!!!!

[AZDriftR]

ok here is the deal.. in my MET intro class we have a project that is supposed to be with a partner. both the ppl in the group work toward thinking about, designing, building, and testing a machine. well i was late to class and becamse the odd man out and have no partner. well that means i have to do the work of 2 ppl all bymyself. so i talked to the professor and he said since there are only so many ppl in the class and i didnt have a partner that he would allow me outside help. well i could think of no better place than this forum for alil outside help. (laugh)

 

[toucci]

cool! (yupnope)

 

[AZDriftR]

design and build a device that will propel itself along a taut line (3/16" diameter, braided, polypropylene clothes line) having an approximate slope of + 1/10. the device must start from rest from a designated location on the line; no push starts are permitted! it must propel itself. the objective is to travel as far as possible from the starting point. obviously, a trial ends when the device looses power and comes to a stop. however, if the device reverses direction, the trial does not end until the device comes to a stop. no portion of the device may be left behind at the starting line

this is a competition! the winninng design will be determined on the basis of themaximum distance traveled for a single run. the project grade will consider originality, soundness of design and appearance.

Design Specs
1. maximum dimentions 4"x6"x8"
2. maximum weight=4 ounces=.25 lbs=114 gmX acceleration of gravity
3. source of energy for propultionn: maximum of one standered NO. 32 (.125"X3") rubberband
4. the device must be designed such that it can be placed on the line and ready to begin a trial within one min of being given access to the line. this includes installation of rubber band, if needed.
5. permissible building materials: no restritions on the type of material used except that all the components must be inexpensive and cost no more than $20 all together.

ANY HELP WOULD BE ABSAFUCKINGLUTLY AMAZING!!!! THANX

 

[AZDriftR]

cool! (yupnope)

ya i nkow it sux... but what i need is like ideas for the propulsion of the machine.. so far i have it being propelled by a propeller and an idea involving 2 gears climbing the rope.. i also need some way to make it so the machine only goes up the rope one way and not back down.

 

[toucci]

here's my idea: a rubber band stretched between two posts, one of them being a T shape with the crossmember and the other a stationary I shape, with the crossmember having teeth that fit into a worm gear on top that is hooked up to a drive wheel

the hard part besides manufacturing will be getting the best gear ratio possible while still overcoming the system's friction

edit: oh poo, I didn't realize the rubber band is that small. in that case I think the propeller idea is the best (and much easier)

as for the one way thing. just buy a one way bearing for the roller.

 

[AZDriftR]

ya the propeller idea is ok but these have to be "original", and i want something cool to work on.. the idea you were talking about sounds really cool but you really lost me on worm gear..hehe. if you can sketch up alil rough sketch in paint or something so's i can understand you thinking that would be awesome. and i can find some way to make the rubberband work with it im sure.

 

[AZDriftR]

does anybody else have any ideas on what might work best? or even some ideas that are alil out there would be cool.. the originality of the design is very important

 

[AndrewF150]

Balloon+little half ping milk carton+straw=mad string traveling machine!!

I know it sounds stoupid, and simple...but taking the same idea you can apply it to a more advanced method.

Basically what I did back in the day(6th grade) was cut a small hole in the back of the milk carton, slip the balloon inside, and than fasten the straw to the top of the carton. Slipped it on string, and than blew up the balloon....let it fly! The little SOB flew down the string....till it hit the wall.

But in your case I can see you have to use a rubberband...hmmm.

In your situation I would probally use a very small pully, that can be put on the line, and than use the rubberband to actually spin it..too hungry right now to think of more....I am gonna go eat and maybe something will come to mind.

 

[Prodigy]

Is it too late to think of ideas?

 

[AZDriftR]

ya.. i mad a machine using 2 coke cans and a string and some balsa wood.... i got a B.. oh well.. thanx anyways

 

[2003blkmp5]

hmmm I dont think this would have enough "steem" so to speak, but what about using some sort of counter weight. where the weight would be attached to a free rod, that also attached to the pully, kind of like a piston on a car, the rubber band would be inbetween acting as a spring... to start it you would pull down the counter weight, and let go to start the wheel. the rubber band would kind of keep it going, as the counter weight bounced up and down propelling the machiene... its just an idea, i dont know how far it would go... but hey, any ideas help...

 

[AZDriftR]

ya sounds like a pretty good idea.. but the project was due last week and i made a fairly decent machine that went 17feet... some kid used his rubber band in a turbine powered machine.. he took 2 coke cans and cut the tops off of them and made a boilerby duct taping them together with a smal hole the size of a penny on top with a tube sticking out.. the he made a smal turbine out of another aluminum can, and a shaft to connect it to a gear. then that gear was attached to a pully, and the intire thing was weighted to stay on the rope.. then he put the rubber band in the boiler! and heated it up (the teacher was like WTF.. but accepted it because ultimately the rubberband was the power ) the hot air turned the turbine which turned the gear and the thing was slow as s*** but went all the way up the rope, and when it got to the top it was still spinning!!!!!

 

[Prodigy]

Cool.

(off topic) - do you have any pictures of your car showing your new wheels?

 

[AZDriftR]

ya my buddy does on his digital..ill have to get some to show you...