fig7 that the drive unit 56 is released from control by the motor 78 at that point and conversely control is re established when the wheel rides off the track an outstanding advantage of the invention is the simplicity thereof for example the computer unit need not perform any computing functions between steps in contrast thereto in previously known devices as the carriages and each of them separately move there must be a function performed constantly in relation thereto but in the present case there need not be any calculations or 34 watching 34 between steps for example in forming the stem 154 of the flower the movement is made from the lower end of the stem to the top thereof and during this movement no sensing or calculating movements need be performed but the computer unit functions according to the information entered at the step represented and then no further functioning is performed or need be performed until the next control step is reached and at that point the information is already entered and the computer unit functions according to that information so entered in relation to this feature just referred to the constant speed of the drive wheel 60 is a great advantage in the simplicity of the apparatus for example the computer unit need not sense any change in speed or to perform any functions because of any change in speed but only perform according to the instructions entered into the computer unit which are based on a constant speed however notwithstanding that advantage it is within the scope of the invention to utilize drive of variable speed and to provide corresponding refinement in computer unit control a further advantage.