Soda Bottle / Pipe Coupler for POV Baton

This is based on the Genesis Poi project.
https://www.thingiverse.com/thing:918847

Can also be used for coupling bottles to pipe for fluid projects!

Got tired of poi, wanted to give baton a try. ~~Secret advantage is that an extra battery can be hidden inside the pipe, or even extra electronics to provide fancier or larger pattern sets, not to mention controls.~~

EDIT 11/19/2017: After trying to twirl for the first time using 1/2" PVC and failing miserably I looked up the standard diam