title: The Child SKSpriteKITnodes in the coordinate system doesn't work
body: <p>The Child SKSpriteKITnodes in the coordinate system doesn't work well I am trying to move the SKSprite nodes from Top To Bottom But they Get stop in the middle ?</p>
  
  <pre><code>ColorCoin *coin = [[ColorCoin alloc] initWithImageNamed: coinName] ;
  
  SKAction *move = [SKAction moveToY:0 duration: 10];
  
  CGFloat screenWidth = [self dropNode].size.width;
  
  
  int x = arc4random() % (int) _dropNode.calculateAccumulatedFrame.size.width;
  
  coin.zPosition =0.0;
  
  coin.position = CGPointMake( x, _dropNode.calculateAccumulatedFrame.size.height-30);
  coin.name = coinName;
  
  [coin runAction: move];
  
  [[self dropNode] addChild:coin];
  </code></pre>