Measure 7 inches in length on the 1x4 with the ruler, mark it off with the pencil, and saw it off. This will serve as the base for your camera mount. Measure, mark off, and cut the same length from both PVC pipes.
Take one of the 7-inch PVC pipes. Attach it to bottom of the 7-inch wooden base by drilling three screws. Drill these screws through the wood then into the back of the PVC pipe. Drill in two screws in the ends, and one screw in the middle to ensure it does not bow. Repeat this step for the other PVC pipe.
Drill holes for the skateboard wheels into the PVC pipes at the bottom of the wooden board. Looking at the open end of the PVC pipe make sure to drill the first hole at the 8 o'clock position. Move farther down the pipe, and drill the next one at the 4 o'clock position making sure to leave enough space for the wheels. Make sure the wheels don't rub together. Take a 1/4 inch bolt, slide it through a wheel, and put the bolt through one of the PVC pipes. Place two washers where the bolt comes out, then screw on a nut. Alternate from bottom right then bottom left of the PVC pipe until you have four wheels on one--two on one side and two on the other. Repeat this step for the other pipe.
Measure and mark off the center of the wooden base. Drill a hole into the middle of the base. Insert the last bolt through the bottom of the wooden base where the PVC pipes are.
Screw on the detachable monopod camera mount. Attach your camera to this mount.
Lay down the remaining PVC pipe, and place the wooden base upon this.