Several musicals and many children's plays call for a "Cinderella-style carriage." A carriage that can actually carry Cinderella, and convey her to and from the stage, can be constructed using ordinary home improvement store materials. Such a project may take the efforts of several talented set builders over a period of days, but the final result is sure to receive a deserved round of applause from a delighted audience.
Determine whether the carriage must be an actual rolling carriage, or whether the unit can be merely mounted on a rolling platform. If it has to be a real carriage, you will need to locate a large, tall utility cart or construct a basic "undercarriage" with suitable wheels that freely turn on two axles. If the carriage can be moved using only a platform as a rolling base (painted black to make it less visible to the audience), construct this base using standard theatre platforms. Attach six or more 3-inch to 4-inch diameter, 360-degree swivel head caster wheels to the bottom of the platform framing so they spin freely. Engineer the weight-bearing requirements of this mobile platform carefully; it's better to have too many or too large casters on the platform than to find out too late that the rolling unit sags or scrapes the stage floor due to too much weight.
Cut 3/4-inch plywood into two long "moustache" shapes that curl up on the ends. These form the long sides of the "carriage box." Cut them to the desired length and height. Cut 3/4-inch plywood into two end pieces for the carriage box, plus any inside bracing. Assemble this carriage box with a top made of 3/4-inch plywood.
Mount the carriage box on the real wagon undercarriage or on a fake undercarriage. A fake undercarriage can be constructed like a table with four stout legs. Brace the legs heavily. Paint the undercarriage black to make it "disappear." Cut "wheels" from 3/4-inch plywood and mount them over the legs. Add a seat or bench to the top of the carriage box.
Test the carriage before proceeding. Seat Cinderella and any other actors on the unit, and test whether the carriage will roll easily under the weight. If not, make necessary engineering adjustments.
Cut sections of 1/2-inch PVC pipe into lengths to form an onion-shaped dome or "cage" for the carriage. Anchor one end of these pipes to the floor of the carriage box using plumber's hardware. Bend the pipes up and then in, towards each other at the ends, so they meet at the top and form a cage shape. Cut an octagon shape from 3/4-inch plywood to form a "cap." Anchor the free ends of the bent pipes to this cap so the pipes retain their cage shape. Cross-brace this cage using wire or 1/2-inch PVC pipe sections. Be sure to leave a space between the pipes for any carriage doors. Make swinging doors from 1/2-inch plywood or PVC pipes.
Paint and decorate the carriage unit to suit.
Use actors costumed as horses, or make horses from chicken wire and paper mache and mount them on rolling platforms.