GROUP 20DMP PRESENTATION

The finished product

Subsystems

2) Rotating door- to implement the opening and closing of the vending machine and allow access to receiving chamber.

1 ) Cup separator - Use of a solenoid to drive a wedge separation design to separate the cups from the rest of the stack. A Cup gripper was also used in order to hold and prevent the cup from tipping over after delivery from stack into the receiving chamber.

3) Outer body casing – the aluminium outer shell provides an aesthetically pleasing design while the shelves provide structural rigidity and hold the whole machine together. The two previous subsystems are located on different levels of the machine.

Rotating platform

Cup separator

Outer body casing

Sensors and

actuators

Roller switch Solenoid motor

The wiring required for the sensors and actuators

Justification of Final Choices

We chose aluminium for the outer body casing due to its aesthetic appeal and its malleability, which would make it easy to shape.

A streamline design was chosen for its simplicity to build and work with. MDF was used for the shelves because it is a soft material to work with

and would allow changes to be made if necessary. It provided enough strength and rigidity to allow us to place our sub-systems on each level without deforming.

The wedge separation technique for cup separating was used due its ease of implementation. The solenoid was used to power this, as it provided the linear motion we required.

We chose the revolving door design due to its user friendliness and the easy in which the actuation could be applied.

Manufacturing and Assembly Plan

Day 1

• Cut internal shelves to the correct dimensions.• Drill holes into aluminium sheet and cut out slot for

door.• Shape cup catcher.• Writing code on to wiz c environment.

Day 2

• Bend aluminium shell to correct shape.• Cut out and shape cup separator• Construct rotating door• Burning code onto microchip and starting of wiring

Day 3

• Add cup support and wedge to cup separating subsystem.

• Attach cup separating support to internal shelf.• Connect cup separator t o solenoid.

Day 4

• Connect bevel gears to motor and to shaft of rotating door.

• Cut storage tubing to correct length

• Construct motor housing and connect motor to bottom shelf

• Connect revolving door to motor

Day 5

• Screw the PCB board onto the middle internal shelf.

• Connect LEDs to outer aluminium shell.

• Modifying code• Testing machine

Challenges and modifications Attaching the shelves to the outer aluminium shell. Due to the weakness of the

MDF in the horizontal direction, the MDF started to split. We attached brackets to the aluminium shell and to which the shelves were attached. This

altered the height that each level had originally been allocated. Aesthetics were affected but the performance remained unaltered.

The bevel gears attached to the motor were not able to provide a great deal of torque to rotate the platform as they were not meshing properly. This meant that the door would not rotate. The motor was directly attached to the rotating platform. This allowed the door to rotate

smoothly. The solenoid used in the cup-splitting mechanism did not have enough stroke

power to make the splitter head return back to its original position. Rubber bands of varying elasticity were tied to the splitter head and tested to see if the head

would return back to its original position. By a method of trial and error, one of the rubber bands were chosen to be included in the final model. However this problem was not fully resolved.

Hard to replicate the precision of our drawings and meant that the machine did not run smoothly as anticipated in the design phase. Lowering levels of accuracy.

In the coding part, we found it difficult to find an algorithm that would re-set the entire device if an error was detected. The user was guided to press the

reset button already present on the electronics board to re-set system if necessary

Motor being re-placed

Merits of our system

User friendliness Simple design A cup gripper which provides the reliability that the cup after

being split from the stack doesn’t tip over. A easy LED-System which directs user about the status. An open-back which allows for the user to quickly reset system.

It is also helpful for maintenance works to be carried out on it. A lot of space on the racks to put tea bags or sugar. It has great

potential to be turned into a system where the liquid is delivered into the cup.

Open back of machine

LED display

Cup gripper

Cost of the product

Our product was estimated at a cost of GBP 85 We would like to sell the product for a minimum of GBP

102, i.e. at a profit of 20%We attribute the cost to materials and actuation

systems needed to build the product.This profit would help us to also cover for the man-

power needed to build the product.

Things we’d like to improve on

Building a better user-interface Implementing more fault check conditions- Use the infrared

sensors to detect cup presence and then start filling. Implementing a direct switch for reset of system-rather than

for the user to go all the way back. A cup stack empty check-which can be implemented through

infrared sensors.

THANK YOU ANY QUESTIONS?