This linear rail launcher works on the the same principle as a homopolar motor. The replacement axle of the F-117A model as seen in this video is made from a steel rod. The parts are added to this rod as noted ( inboard to outboard on each end ) one 3/16"dia. flat brass washer, one 3/16" steel nut with threads drilled out, one 1/2" dia. x 1/8" Thk. nickel plated rare-earth ring magnet, two 3/16" steel washers and one 1/2" dia. x 1/8" Thk. nickel plated rare-earth rod magnet. Note: Make sure all the poles of the outboard magnets are the same ( facing out ) or the linear launcher will not work. A live demonstration of this rail launcher will be held at "Malvern Town Centre" on Saturday March 1st, between 10am to 4pm. Scarborough, Ontario. All viewer are welcome to attend...and its free...