Insert the timing pulley into shaft of the stepper motor with the tightening bore end first. Reference the photo for the position.
Depeneding on how loose or tight the tolerances are, you may need to apply some adhesives to permanently attach the parts together. I recommend applying directly to the bottom of the clips and sliding them in.
Congratulations, the build is complete!! All that's left is to do is test the connection and get some epic timelapses!
Download and launch the Adfruit bluefruit LE connect mobile on your device. Power on the Arduino. The Bluefruit LE module should appear in the list of devices. Tap on the connect button and then the control pad.
Now you can press the button to move the slider! Check the next page for usage details.