The reason it is so fast is simple.... it doesn't carry the battery. Power is supplied by the wires leading to the airplane. This means you can get crazy with motors and props but not have to worry about weight.
Here's what you'll need. I'll go over the details in the text but i always give options and ways to make it simpler or more complicated...
For the Airplanes You'll need:
-An assortment of small electric DC motors... 3-9 volts...
-An assortment of propellors... whatever you can find.
-Thin, 3mm foam sheets or foam trays from your butcher.
-Balsa stick, about 16" long by 3/16" by 1/4"
-Wire 22G stranded, about 2 feet.
-5 minute epoxy
-1/16" welding wire or piano wire
-small plastic wheels.
-soldering pencil, solder.
-Power supply... a variable type with at least 12volts at 2 amps would be good. If not around, just use a battery.
-If you want to get into electronics, at least one multimeter.
For the Tether Pole You'll need:
-1" dowel 3 feet long, 1/4" dowel 1 foot
-3' square 1/2" plywood
-2 skateboard bearings
-22 G enameled wire... about 40 feet.
-22 G stranded wire... about 30 feet.
-5 minute epoxy
-A handful of wood screws.
-Hand drill with an assortment of bits.
-a saw if you need to cut the wood base.
-soldering pencil and solder.
Step 1: The Layout and Design
What i will supply is a set of worksheets i use for basic design layout. Here's the basic proportions worksheet. It is attached as a WORD document, too.
Basic Airplane Proportions…
The wing length should be about 5-6 times the width. The width of the wing from leading edge to trailing edge is called the CHORD.
The length of the body of the airplane (called the FUSELAGE) should be about 70-75% of the wing length.
The distance from the leading edge of the wing to the propeller should be about 15% of the wingspan. (wing length)
The distance from the leading edge of the wing to the horizontal stabilizer should be about 3 times the chord of the wing.
The horizontal stab should be about 25% of the wing area.
The vertical stabilizer should be about 10% of the wing area.
The plane should balance at about 25-33% of the wing chord.
For older kids i will discuss the proportions than let them loose. I make sure they do everything with paper and pencil first, check over the designs than give them foam. If you need a more step-by-step here is another worksheet i use for kids to setup the design...