Spring Sprinter

Discussion in 'The Projects Forum' started by Hello, Jan 12, 2009.

  1. Hello

    Thread Starter Active Member

    Dec 18, 2008
    82
    0
    Can you please have a look at the attached file.

    It is a design project.
    I am having difficulty in understand what a '..... moves-up an inclined flat surface with a gradient of 1 in 20' means.
    Does it simply mean that the horizontal distance is 20 times that of the vertical height at which the device will move along?

    Also, can anyone think of a possible device that meets the requirements?

    Any help is greatly appreciated.
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Yes, the rise is one inch for every run of 20 inches.

    I probably had a couple of windup toys that would have gone the distance. There are compression springs and tension springs as well as clockwork springs.
     
  3. steveb

    Senior Member

    Jul 3, 2008
    2,433
    469
    Yes, but how do you know I'm not your competitor trying to mislead you? :)

    Aside from recommended devices, you should do calculations of energy and power required. Try to estimate friction force, potential energy change going uphill, stored spring energy etc. It should be feasible to write a computer program that predicts performance. If you can make an accurate model, your chances of optimizing the device and winning are much higher.

    Also, think about materials that will help. For example, Teflon is a good low friction material. Maybe steel rubbing against Teflon without lubrication will outperform another competitor using lubricants with metal on metal.
     
    Last edited: Jan 12, 2009
  4. Solar1

    Member

    Jan 12, 2009
    15
    0

    The device you build must go up a ramp (right triangle) of sides 1 unit high and 20 units long. I suggest looking into a fly-wheel driven by a wind-up sping assembly similar to a child's toy car/truck design.

    This would easily carry the load on the flat surface and gradient.

    Best of luck.

    Solar1
     
  5. Hello

    Thread Starter Active Member

    Dec 18, 2008
    82
    0
    Thanks,
    Very good idea.
     
  6. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,170
    395
    Just thoughts: 500 gm load @1:20 = 25 gm pull[ + losses]=50 gm. Ballbearing wheeled trolley going up i: 20 ramp took 11 nickels US.with 3 rolls of nickels as load. nickel= about 5.35 gm, so load = 642 gm, force = 58.3 gm, or just for 500 gm ,force =45 gm. So for the work ti be done ,200 cm X 50 gm = 10,000 cm gm. A small spring,1.2 cm od X 3.5 cm long with .091 cm dia. wire requires 2kg to stretch 10 cm;average 5 cmX 1kg or 5,000 cm gms., need 2 springs. Now for the questions: any limit on dementions of trolley. What facilities do you have to work with, drill press table saw,tap & dies,etc. ;or do you have to purchase everything??
     
  7. Hello

    Thread Starter Active Member

    Dec 18, 2008
    82
    0
    'I suggest looking into a fly-wheel driven by a wind-up spring assembly similar to a child's toy car/truck design'.

    I can't think of how to assemble a clock-spring in the fly-wheel for it to move, as you suggested.
    I have attached a drawing of the fly-wheel, can you please have a look at it. Maybe you can think of a possible assembly.

    Any help is greatly appreciated.
     
  8. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,170
    395
    Tell us about your windup mechanism. On one winding how many revolutions does the outpot shaft make? What is the torque at start and finish. Attach an arm to shaft, say 10 cm and with spring scale measure force. Skip flywheel for now.
    What facilities do you have to work with? ;or do you have to purchase everything? Any restrictions on size of trolley? How much space for load?
    Preleminary trolly drawing finished, need answers.
     
  9. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Removed bad idea
     
    Last edited: Jan 25, 2009
Loading...