Free 186 More Best Homemade Tools eBook:  
Get tool plans

User Tag List

Results 1 to 6 of 6

Thread: Hand-cranked shell game

  1. #1
    Jon
    Jon is online now Jon has agreed the Seller's Terms of Service
    Administrator
    Supporting Member
    Jon's Avatar
    Join Date
    Jan 2012
    Location
    Colorado, USA
    Posts
    26,433
    Thanks
    8,100
    Thanked 40,246 Times in 11,775 Posts

    Hand-cranked shell game

    GIF and short video of a hand-cranked shell game from Per Helldorff.


    https://diqn32j8nouaz.cloudfront.net/shell_game.gif


    186 More Best Homemade Tools eBook

  2. The Following 2 Users Say Thank You to Jon For This Useful Post:

    PJs (Jan 22, 2017), Seedtick (Jan 22, 2017)

  3. #2
    Jon
    Jon is online now Jon has agreed the Seller's Terms of Service
    Administrator
    Supporting Member
    Jon's Avatar
    Join Date
    Jan 2012
    Location
    Colorado, USA
    Posts
    26,433
    Thanks
    8,100
    Thanked 40,246 Times in 11,775 Posts
    I still haven't figured this one out. Clever use of moving magnets?

    2,000+ Tool Plans

  4. #3
    Supporting Member mklotz's Avatar
    Join Date
    Aug 2015
    Location
    LA, CA, USA
    Posts
    3,525
    Thanks
    362
    Thanked 6,559 Times in 2,161 Posts

    mklotz's Tools
    Suppose EACH cup contains a ferrous ball held to the inside top of the cup by a weak magnet. By moving a stronger magnet concealed beneath the table under a given cup, the ball in that cup is pulled from its restraining magnet and held to the table when the hands are lifted. When the hands come down, the under-table magnet moves away and the ball is sucked back up into its cup.

    The rotating circular platter has pins placed at different radii. I think they are the ones locating the under-table magnet.

    Just a guess, but that's how I would think about designing it.
    ---
    Regards, Marv

    Failure is just success in progress
    That looks about right - Mediocrates

  5. The Following 3 Users Say Thank You to mklotz For This Useful Post:

    HobieDave (Mar 22, 2020), Jon (Jan 23, 2017), PJs (Jan 23, 2017)

  6. #4
    PJs
    PJs is offline
    Supporting Member PJs's Avatar
    Join Date
    Sep 2014
    Location
    Northern CA
    Posts
    1,844
    Thanks
    8,427
    Thanked 1,129 Times in 725 Posts

    PJs's Tools
    Good catch Marv, Thanks! I was wondering my self how the magnet in the hands might work but did notice the little flags on the horizontal disc seemed to be doing something else.
    ‘‘Always do right. This will gratify some people and astonish the rest.’’
    Mark Twain

  7. #5
    Supporting Member mklotz's Avatar
    Join Date
    Aug 2015
    Location
    LA, CA, USA
    Posts
    3,525
    Thanks
    362
    Thanked 6,559 Times in 2,161 Posts

    mklotz's Tools
    You can see the flags pressing on a small, movable wooden bar that's under the table.

    I based my analysis on the fact that the spherical ball does not roll when it's revealed. Given the vibration induced by the hand-cranked motion, some force must be restraining it; the logical candidate is magnetism.

    The gray skirt on the table is not just decorative; it's there to hide your view of what's going on underneath.
    ---
    Regards, Marv

    Failure is just success in progress
    That looks about right - Mediocrates

  8. The Following User Says Thank You to mklotz For This Useful Post:

    PJs (Jan 23, 2017)

  9. #6
    PJs
    PJs is offline
    Supporting Member PJs's Avatar
    Join Date
    Sep 2014
    Location
    Northern CA
    Posts
    1,844
    Thanks
    8,427
    Thanked 1,129 Times in 725 Posts

    PJs's Tools
    You are the Man Marv...and your observation just made me figure out why the pegs are in an elliptical pattern to vary the motion on the lever to move the magnet in a linear motion for each hand. Still can't figure out what that inboard one is for though! This is a good test of critical thinking, imho.



    2,000+ Tool Plans
    ‘‘Always do right. This will gratify some people and astonish the rest.’’
    Mark Twain

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •