A picture of the automatic cocktail bar made for “Merke 2018, Wytgaard, theme Wybiza”. This machine is one of the controls í’ve build for the last -i think- 6 years based on the AFSM software, for our festival. Not planning to build a new one for this year (it is a lot of work for a 3 days village festival), i could not resist building this automatic “limonade cocktail bar”. The bar is build for the children who can mix a glass of limonade. There is a choice out of 3 flavors. The choice of one of the flavors can be made by pushing one of the white eluminated buttons. Then press “start” and the control will prepare the drink. Every drink is prepared while playing an appropriate song.

The technic of the bar consists of:

  • Design philosophy; when a button or LED is blinking, you must do something! In this way the cocktail bar is simple to operate, even for children… 
  • A glass transport system to place the glass under the chosen dosing point of the limonade concentrate. This system is made by 2 RVS sliding bars, a RVS spindle and a stepper motor for driving the spindle.
  • A limit switch. When starting the system, it has to determine the position of the glass transport. This is done by transporting the plateau to the right until it reaches the limit switch. Now the controls knows the zero position and transports the glass to the “start” position (stepper motor 200 pulses is 8mm).
  • An ultrasonic measurement to determine if there is a glass present on the glass transport. The measurement is also used for controlling the change of a glass; an already prepared glass on the transport has to be removed to start a new cycle as a condition for a new cycle.
  • 3 membrane pumps for the dosing of the limonade (based on a fixed time for every flavor).
  • 2 valves; one for dosing an amount of fresh water in the glass and one valve for refreshing the garden hose attached to the machine. For the dosing of drinkwater into the glass; a garden hose is used. Because of the relative long length of the hose it must be refreshed. So when there is no cycle busy, every 2 minutes water is tapped from the garden hose and is drained. This to prevent children to get diarrhea!
  • 5 iluminated buttons for making the limonade mix; in fact the user machine interface.
  • Mega2560, Ultrasonic device, stepper motor, 8 channel relais board, 5 arcade buttons, an APC220 for the communication with a PC and a lot of mechanical stuff.
  • Every suction side (highest point of the concentrate hoses of the bottles) is provided with a very small hole. This prevents the siphoning of limonade concentrate to the dosing point.
  • Little check valves prevent most of the dripping of concentrate (some pressure is required to open the check valves in the normal open position).


  • When pressing the 2 most right white buttons for 5 seconds, the installation is going into the service mode (all LED’s in the buttons are commanded in a “running” loop). Now it is possible to command the pumps and valves by hand, by pushing the related buttons. This is done for pressing the limonade out of the system when the installation is stopped for a while; remove the limonade out of the bottles, fill with water, go to the service mode and push the white button…. Leave the service mode by pressing the same buttons for 3 seconds.
  • The earlier mentioned CIP fase of the garden hose to prevent from getting diarrhea.
  • When a choice is made and “start” is pressed; a message is send to the PC with the choice. This triggers one of the three songs to start while preparing the most delicious drink. The songs are played by the PC running the scada part of the AFSM (visual basic).