The Cakes N Cookies Froster (CNC) is an extension to an existing CNC machine. We bought cake decorating supplies and modified our CNC software to squirt cake frosting at the right time to make a happy Christmas decoration. The 'froster' is made from a decorating bottle for cake frosting, this is inside of a salad dressing shaker, which encases a stepper motor. The stepper motor drives a push plate to force out frosting. To prevent drip, the stepper motor is programmed to retract slightly between strokes (drawing). During strokes the push plate is continuously advanced at a slow speed set by a potentiometer.
Video: http://www.youtube.com/watch?v=P5hXYrbJSrU
Overall what happens is the CNC software reads a file that we've designed, in this case the word "xmas" (we apologize for the non-use of Christmas but the cookie is simply too small!) with a circle around it. This pattern is translated to movements (strokes) by the CNC software. Stepper motors on the CNC machine executes these movements, so the machine moves into position for each part of the pattern. At the same time, an additional stepper motor in the cake froster section pushes out frosting at appropriate intervals to make the pattern. The froster head is lifted between each stroke because we found that this makes a nicer pattern.
We encountered some frosting problems with this: it is not great for small cookies, since the frosting is so runny, either a stiffer frosting or a larger cookie might be better for a more precise design. Another, and more serious problem is what to do with the many cookies that were prototypes, and are now rather ugly, sugar covered rejects that we must somehow find a way to 'dispose' of. :)
Hope you have a happy Christmas! Next up...laser etched cookies... mmm toasty!
