A very original, budget oriented (high tech) effort there redbastard
That would defivately be a medal candidate at our annual "Spring Thaw" nav-rally for the award; "most innovative home build roadbook holder". We've had some doozies over the years; ranging from dozens of various transparent plastic lunch boxes with manually operated wood dowel spindles, a tobacco can with lexan goggle lens cover and only one drive spindle. There have been cigar boxes of various types, and once even a small metal munitions box that the guy had fit a little electric drive motor to!
words of advice for you (I am sure you can relate to, when the school is over
1. Watch out for bushes, scrub and overhang brances to the left side of the trails/tracks.
2. Don not
stack/fall/crash the bike on the left hand side...
Else, I am imagining (in my minds eye), the image of an electric drill drive unit dangling from the left handgrip attatched by the wires, with the white plasic remains of a shattered Acerbis RB housing sitting on the mounting brackets, and a toilet roll of white paper streaming from the handlesbars in the breeze!
Good luck at the ride!