Ideas for a Robotic arm using PLC

Hi! I am thinking to build a robot arm using PLC for our final year project, can you give me some ideas on how to do it? we are currently planning to use pneumatics and PLC for the "brain" of the arm, and the main purpose of the arm is to automatically dipped something into paint for a period of time and move it to a certain location. any Idea will be appreciated, thanks !

i am not sure i understand what is meant by a robotic arm in this case. in order for something to be a robotic arm, it need to have some positioning capabilities.

normally this is accomplished by use of servos but post mentions pneumatic. pneumatics are normally used for fixed travel (length of cylinder stroke) or for travel that is restricted by process (gripper stops moving when object is held, amount of travel depends on size of object held by gripper). if you plan to stop cylinder midway as a way to control position, you will be fighting loosing battle. pneumatic pick and place machines are very simple and easy to program but as mentioned, travels are predefined. if you are looking for sample code, check example "pick and place" here
https://forums.mrplc.com/index.php?app=downloads&showcat=17
it is a simple counter based FSM, incl. mode control and diagnostics.

to control several servos using PLC is possible of course but the cost will go through the roof. if you are students doing final year project, why not use microcontroller and hoby servos or stepper motors? you can get low cost yet powerful development kit like STM32 Discovery Board for under $20.

even better than servo control is stepper motor control for position. Direct drive from micro...

and I agree with "panic_mode".... PLCs cost way way way too much... it's just a glorified microcontroller that someone preprogrammed with a programmable interface and modular I/O system. For instance, I supply controller boards @ < $200 that do the same job as a $1200 PLC.

Tnx for your replies, I think you guys are right, I am now planning to use arduino instead of PLC, and I will also use a stepper motor as the actuator, could you give me an idea on how to make a user interface for this where we can set the timing and positioning of the arm?