Study "Assembly Motorized.skp".
Obtain the following:
1) Gear Motor - Pololu part number 2366 (http://www.pololu.com/product/2366).
2) Coaxial Power Jack - Radio Shack part number 274-1583.
3) 1.5 Vdc Power Supply - Radio Shack part number 273-315 with the "N" style plug (273-345, you get one free with the power supply).
4) White lithium grease.
5) Light machine oil.
Print the thing parts.
This is a challenging build. Test fit all parts before final assembly. Depending on your printer settings, the colors you choose, etc., you may need extensive or minimal sanding, filing, scraping, etc. for all parts to function properly. For example, the cams and "Gear Axle.stl" should fit on "Axle.stl" tightly. Also, the ripples should slide easily in "Guide.stl"; if not, trim the guide holes in "Guide.stl" with a modeling knife and sand, file and/or trim the lifters on each ripple until they do.
Solder a 3" wire between the gear motor "plus" terminal and the coaxial power jack "Center" terminal. Solder another 3" wire between the gear motor "minus" terminal and the coaxial power jack "Shield" terminal.
Press "Gear Motor.stl" onto the gear motor shaft.
Press the gear motor assembly into "Base.stl.
Assemble the axle as shown in "Assembly.stp". Note the top of "Axle.stl" has small tick marks that indicate the position of "Gear Axle.stl" and the cams. "Gear Axle.stl" should be centered over its tick mark, and the cams should be located to the outside edge (see "Assembly.skp") of their respective tick marks.
Place the axle assembly into "Base.stl". You will need to slightly spread the axle mounts on "Base.stl" to install the axle assembly. Once installed, if the assembly does not spin smoothly, remove and slightly enlarge the axle holes in "Base.stl" using a 5/16" drill bit (in reverse), file and/or modeling knife. Lubricate the surfaces of the cams and bushing surfaces with white lithium grease. Finally, when you are sure the cams and gear are correctly positioned and perpendicular to the axle, a small dot of thick cyanoacrylate on the gear and cams will aid in holding them in position.
Install the coaxial power jack into "Guide Tube.stl"
Press "Guide Tube.stl" onto "Base.stl" making sure the alignment pin in "Guide Tube.stl" aligns with the alignment slot in "Base.stl". Also make sure the wiring does not interfere with any components of the axle assembly.
Press "Guide.stl" into "Guide Tube.stl", making sure the alignment slot in "Guide.stl" is in alignment with the alignment pin in "Guide Tube.stl" and that "Guide.stl" is fully seated in "Guide Tube.stl".
Lubricate the holes in "Guide.stl" with light machine oil.
Insert the ripple components into the slots in "Guide.stl". The angled surfaces of the lifters must face the rear (towards the coaxial power jack). They should drop in easily with no assistance. If they do not, remove the ripple components and "Guide.stl", and sand, file, trim with modeling knife, etc., until they do, then reinstall.
Plug the "N" style connector onto the power supply, positive tip.
Plug the connector into the coaxial power jack.
Plug the power supply into a wall outlet.
Run the initial assembly at 6 Vdc for about an hour or so to allow break in, then at 3 Vdc for about another hour or so. After that, you should be able to run this thing at anywhere from 1.5 Vdc to 6 Vdc.
Admire your Ripple Effect, and make some waves.