How to add gravity simulation - on motion study in SolidWorks 2012?

This is how I see assembly in SolidWorks:
In assemby mode you add parts and mates between them- mainly for making 2d or check collisions.
When you want make a movie showing how your machine works - you should use motion study and animation option.

And If you want make a gravity simulation or other contact between elements you should use motion study- BASIC MOTION option. (of course you might make a movie of this)
And this tutorial is about BASIC motion elementry options.
Link to model of this tutorial:
SolidWorks - Ball separator, classifier - motion study

  1. Step 1:

    We gonna create ball classifier and add the gravity.
    The balls will roll down the gutter and fall to separate boxes.

  2. Step 2:

    New part. Draw a ball.
    I make 4 configurations of diameter and 4 displey states for each diameter.
    So i have one file to ball and 4 different balls.

  3. Step 3:

    New part. 3d sketch- patch of gutter
    Another sketch - Closed profile of gutter.
    in the same part i draw 4 boxes- shell and pattern options.

  4. Step 4:

    New assembly. Add gutter and some balls together.
    The balls are inserted in very unpleasant positions so we must add the mates.
    Click one clik mates- click tangent, click one ball and one face of gutter.
    repeat all for another face of gutter and the same ball.
    The ball is in good start position for gravity simulation.
    Do the same for each ball

  5. Step 5:

    Now it is time for simulation.
    Click on tab Motion Study in Left down corner in SW.

  6. Step 6:

    Add gravity - click on green apple.
    Choose direction of it. In our case it will be X axis.

  7. Step 7:

    Clik CONTACT option.
    Next odd objects to contact in simulation. All objects in our case.

  8. Step 8:

    Click Calkulate button

  9. Step 9:

    And this is the poit when our assembly MATES gives us problem.
    The balls rolls down the gutter with the gravity but they are still in TANGENT MATE.
    Balls stops at the firs wall.........

  10. Step 10:

    In motion study tree ( not assembly TREE!!!!) we choose all tangent mates. right click and SUPPRES.

  11. Step 11:

    When all is done click another time calkulate button and wait.
    The balls shall roll down and fall to boxes......