Mounting holes for motor: 22mm (across) m3 (can be edited with included step files)
please use a motor with high torque, and make sure your cable is fixed and cannot move too much, otherwise the cables will just get pulled to the side by the tape

The two black parts attach with 3x M4 bolts. the bolt is supposed to thread itself and stay attached. a nut is not necessary.

Printed black in PETG-GF and orange in orange PLA prusament. 

For the part that holds the tape, it is attached with a long m3 screw and 2-3x 3x10x4 bearings which can be pressed fitted in.

Some 9v batteries vary in size (especially cheap ones). Double sided tape may be needed if your battery is not tightly held.

The DPDT switch hole is 13.5*20mm and the wiring diagram is in one of the photos

I encourage editing your .step file to fit your motor and tape roll

 

Inspired by this video. This is a portable 3d printed version with less hardware