Introduction: Electrostatic Turbine: Basic & Enhanced Versions
Static electricity is high voltage (HV) at low current. That unexpected ZAP! occurring when you walk across a carpet and touch a metal object demonstrates HV conduction by ionized air particles. Ion wind turbines use electrostatic forces acting between these particles to produce mechanical movement.
I decided to go green by making this desk-top project from mostly dollar-store hardware; re-purposed plastic, cardboard and aluminum disposables from my kitchen recycling bin as well as some curbside junk from the neighbors next door. The turbine uses foil electrodes that encircle a plastic, tubular rotor. Each electrode has a sharp edge that sprays a stream of positive or negative ions on the rotor's surface. When these electrodes are arranged so they alternate in polarity around the rotor, each electrode repels a rotor segment carrying the same charge and simultaneously attracts that rotor segment carrying charges deposited by the preceding electrode.
Many sources of static electricity --from old CRT screens that "crackle and pop" when powered up, to room air ionizers -- will spin a reasonably well constructed turbine. You can view an enhanced version, constructed from better components and featured on this page w/the basic version, in operation here:
Step 1: Parts List for Basic Version
Step 2: Make & Line Rotor Cylinder
Construct rotor by removing the top and bottom ends of a cat food container to form a 2” long cylinder. Remove label and sand edges with fine paper until level.
Cut aluminum strip to specified size and line inside of cylinder. Trim width as needed to minimize overlap. Strip will serve as a conductor to attract ions to the rotor and also provide a seat for the rotor disks.
Step 3: Prepare Rotor & Flywheel Disks
Covers from 3-ring binders are perfect sources for 1/8” cardstock used for this project. First, remove the plastic sheathing from the binder. Cut and drill three disks as specified for the rotor and flywheel.
Insert the #6 x 1-1/2” metal bolt through the holes. Clamp disks firmly against the bolt head with a lock washer and nut. Chuck assembly in an electric drill. Using a sanding block and medium grit paper carefully grind disks to a diameter of 2-1/4.” Rub a thin layer of glue on the surfaces and edges of the disks to strengthen the cardstock. Allow disks to dry and sand lightly with fine grit paper until surfaces are smooth.
Step 4: Assemble Rotor
Press fit one disk into each end of the cylinder; they should fit snugly and rest against the aluminum liner installed in STEP 2. The outer disk surfaces should be flush with the edges of the cylinder. If the disk diameter is too small, just wrap some paper tape around the circumference to achieve the necessary diameter. Trim excess tape until disk surfaces are level.
Bond the liner to the inner cylinder wall with a small amount of glue. Do not glue the end disks in place at this time — you will need to balance the rotor later. Place the third disk aside for later use in STEP 13.
Cut the rotor shaft to size and slide it through the disk centers. Make shaft collars by removing threads from two #6 nylon nuts with round hobby file until they fit snugly over the shaft. Slide one collar to the end of the shaft and secure with glue. Place this assembly and remaining collar aside at this point.
Step 5: Cut, Mark & Punch Rotor Cage Disks
Cut and drill center holes for the four disks to make the cage floor and roof. Remove 1/8” from the edges of the disks to make a flattened base for mounting your turbine. Sand edges until level.
Mark placements on one of the disks with a protractor to accommodate four support columns and four power rods. The placements must be equally spaced at 45 degrees and 1/4” from the circumference. Use this disk as a template for the three remaining disks.
Make the eight placement holes in each disk with a paper punch. Verify alignment of the holes as well as the flat edges of all disks. Apply glue sparingly to join two disks to make the cage floor. Repeat this step with the two remaining disks to make the roof.