Something different. How about this.....

Started by unknown · date unknown · 16 posts

1. Steve

   #1 · 31 Aug 2012

   Dear members,
   
   Sometimes you see other interesting things on the internet, like the motion wheels with help of magnets.
   Have a look at this video.
   
   Do you think this is for real?
   http://www.youtube.com/watch?v=RkLfpXpO5sQ&feature=channel&list=UL
   
   I also attached it...

    Perpetual Motion Machine. Magnetism & Gravity..flv

2. sebosfato

   #2 · 31 Aug 2012

   And they said was impossible to make a perpetual motion... ha
   
   good one steve... thanks
   
   I will construct an improved version of it today for fun...

3. Steve

   #3 · 31 Aug 2012

   I wish i had the time you have available..
   
   Steve

4. sebosfato

   #4 · date not recorded

   Quote from: Steve on August 31, 2012, 12:22:16 pm

   I wish i had the time you have available..
   
   Steve
   

   
   Wish i could have some money and at the same time still have time, i'm not efficient trying to get a balance... Or i work too hard or don't work at all =) .   
   Its all about making decisions...
   
   I'm going to use a bicycle wheel for this stuff i will put the iron ball inside the tires and run it with a magnet...
   
   
   hope it works =)

5. Steve

   #5 · date not recorded

   May i say that you found a very smart way to replicate this? 
   
   Steve

6. sebosfato

   #6 · date not recorded

   Helo Steve
   
   The idea was nice... but didn't worked as i expected  the steel ball i got was too light... it was 15mm diameter... an probably the bicycle wheel was too heavy, and not well balanced.
   
   I had to buy a neodimium block 20x20x20 too because i had no magnets here to play...
   
   Thinking about the torque
   
   T=F x r *sin(teta)
   
   And F=M*G
   
   
   ....
   
   I don't know if the video is false, since the ball should be attracted in the direction of the magnet and than stops there it shouldn't spin further... maybe thats why he didn't let it run for too long... I mean the magnet will attract the all points of the sphere it will find equilibrium... i guess
   
   What you think about?

7. Steve

   #7 · date not recorded

   Hmmm, finding its equilibrium might be true....
   Not sure, however.

8. Steve

   #8 · date not recorded

   It seems even to accelerate in the beginning...

9. sebosfato

   #9 · date not recorded

   http://www.ebooksread.com/authors-eng/gardner-dexter-1822-1908-hiscox/mechanical-appliances-mechanical-movements-and-novelties-of-construction-for-ala.shtml
   
   This is the book the guy mentioned at the start....
   
   I watched it very close...
   
   the sin of 20° is 0,34
   
   so the torque the ball should cause to turn the wheel is the mass of the ball times G times 0,34 times the radius of the wheel...
   
   the problem i see is that the moment of inertial of the ball is much smaller than the rotor... thus the transference of rotation is really poor...

10. sebosfato

    #10 · date not recorded

    Maybe the wheel should not touch the external radius of the sphere... this way it can be out of equilibrium.... i guess... i'm building  new one with two children bicycle wheels =)
    
    It will look just like the one in the video, except that one seems made of wood probably balsa or something else light weighted,,,
    
    
    notice how the ball stands close to the corner of the magnet... maybe i need a longer magnet to achieve this effect...

11. Steve

    #11 · date not recorded

    Which kid cannot bike now anymore?
     

12. sebosfato

    #12 · date not recorded

    Good one !
    
    I bought a 40mm steel ball... it weights around 260g... so 2,5 newton... the wheels are plastic...
    
    
    
     

13. Steve

    #13 · date not recorded

    Quote from: sebosfato on August 31, 2012, 23:43:19 pm

    Good one !
    
    I bought a 40mm steel ball... it weights around 260g... so 2,5 newton... the wheels are plastic...
    

    
    Thats a good size ball. Iron?

14. sebosfato

    #14 · date not recorded

    here it is.., but no success yet in making it self spin =)
    • 
    • 

    Foto criada em 2012-09-01 às 16.34 #3.jpg Foto criada em 2012-09-01 às 16.34.jpg

15. Steve

    #15 · date not recorded

    Great second attemp, boss!
    You need more magnetical attraction?

16. sebosfato

    #16 · date not recorded

    Actually i don't know.. i need now more time to improve it... the magnet is so strong that the ball opens the wheels making it drop.. i need better solid rotor... i'm planing to add some screws for that task...
    
    Is really strange... how can it spin?...
    
     when it should be working i will make some more images...
    
    
    I'm thinking if the length of the magnet and its geometrical configuration relative to the sphere diameter is a parameter to play with...