The Print and Cut station was responsible for printing the picture selected by the user and and cutting it to the appropriate size and shape.  In order to cut the paper we decided to use a method similar to a hole punch.  The paper would feed in between two plates, and when in the correct position the plates would squeeze together clamping the paper.  Once clamped a punch would come up from underneath the paper to cut it.  The upper and lower plates were made 1/2" thick in order to help guide the punch and allow the punch to remain recessed in the upper plate. 

The Dispensing station was responsible for singulating the button components, the front, pin backing, and mylar.  Because of the size and shape of the buttons it is very difficult to singulate them automatically as they will easily nest or tangle.  As such cartridges were designed with a slide that would hold several pre-separated parts to allow for automatic running.  The parts would slide down the cartridges and load into a fixture, when a part was detected in the fixture it would extend to the pickup location for the gantry robot.  As the fixture slid forward the cartridge opening would be blocked to prevent more parts from dispensing.  The cartridges could hold 15-20 parts each, allowing several buttons to be made before reloading was necessary.

The assembly station is where the various components are put together and crimped into a button using a pneumatic press.  The crimping operation used to produce a button happens in two parts, requiring three dies.  The button front, picture, and mylar are placed in the first die, a press operation is done and the components are then held in the upper die.  The button pin backing in place in the second die and another press operation is done.  In this operation the front, picture, and mylar that are already in the upper die are crimped around the pin backing in the lower die.

To allow for this two stage pressing operation we decided to use a rotary table.  The two lower dies are mounted to the rotary table and braces are placed under to presses to prevent the table from warping during press operations.  This station also performs an inspection on the picture after it is placed in the first die that will check its orientation and correct it if necessary.

The rotary table is also useful for reducing the length of travel for the gantry robot as it can move the dies closer to the pick locations of each component, as well as presenting the completed button to the packaging robot.

The packaging station removes the completed button from assembly and places them either in a box for packaging or down a chute to present it straight to the operator.  The HMI station communicates which selections the user has made for packaging method, quantity, and when to eject a box.  A Lynxmotion SES Kit hobby robot was used as the material handler for the station and boxes are presented to the robot using a conveyor system.

The gantry robot is the main material handling device to the system.  It is built using Allen Bradley servo motors and Ultra 3000 controllers, extruded aluminum for the frame, and 1/2" diameter ACME thread lead screws for the X and Y axes.  The gantry is capable of +/- .001" accuracy in both X and Y axes and can be programmed for various speeds and accelerations.  The Z axis is a simple pneumatic cylinder with a 2" stroke with a vacuum gripper on the end.  This very short cylinder was used because all the pick and place locations were designed to be at the same height, this was both to simplify the picking and placing of parts as well as reducing the distance each component would travel.  Since a vacuum gripper was being used we ran the risk of the components shifting, especially the paper and mylar, as they moved from one spot to another.  We minimized this risk by keeping both reducing their vertical and lateral movement.