Can't get ball over net with pendulum serve

I have been trying to learn the pendulum serve.  However, the great majority of the time, the ball does not go over the net, and does not have much forward velocity.  However, it does have a lot of backspin, as it will roll back to me after hitting the net.  What should I do to give it more "oomph" to get over the net?

Hi Evan,

Try to hit the ball more down into your side of the table and hit it harder.  Don't worry if it bounces high to start with.

The first bounce can be about 30cm from your end of the table.  Hit it hard!