Serving with pure backspin

Hi Pingskills! 

I have recently been doing a number of backspin serves. I believe I have the technique right (bat angle is facing up, even backwards!) and the fine brushing contact, getting plenty of spin but somehow still manage to get some side spin. Is this unavoidable due to the pendulum motion? How can I avoid putting sidespin on the serve and just get more backspin?

I figured if I don't follow through the motion of my serve it doesn't give me enough power and spin, so I've tried following through but the sidespin is unavoidable. Hope this makes sense.

Thanks! 

Hi Derrick,

The sidespin happens because the bat is tilted with the end of the bat pointing slightly towards the ground.  If you lift the end of your racket up so that the racket is completely flat to the ground you can get straight backspin.