The curly Q on top of the tensioner post can be positioned in a number of ways.
It can allow for "straight thru" yarn path which does not add any additional tension to the yaren as it goes onto the ball winder.
The normal position, however, is about 20-40 degrees off of center which means you turn it away slightly from the spindle by the amount equal to 1/2 or 1 complete 45 degree angle. Turn it toward the direction of the rotation so as to "feed" the rotation with yarn.
DO NOT make the yarn turn 90 degrees as it exits the curly Q or that will cause severe tension to be added which will make your ball tight and may cause a wonky ball.