Hi Tim,
Firstly this is great to see videos being sent in to us and we really think it’s a god way to learn, watching yourself and then getting feedback. You are getting a really nice contact and a lot of backspin on some of these serves so that’s great!
To get the serve to go long you do need to reduce the feeling of brushing under the ball slightly and go for more speed, so at the moment your bat angle is great for creating loads of spin as you come under and up the back of the ball however to get the serve longer you need to keep the bat angle so you can chop down the back of the ball and hit through towards your opponent more.
This is quite difficult to explain in text so I have added a video to show you what I mean and explain it better, I hope this helps!
