Hydraulically actuated Robotic arm

As soon as the NIT Trichy's pragyaan'13 is launched, I did a survey on the competitions as usual there are competitions on Line Follower bots, Obstacle avoider bots . But, one competition was something different that is designing a Hydraulically actuated robot arm, which means absolutely without using any kind of electronics / motor actuators we need to design and accomplish the task of rearranging the disordered cups in order. This seemed a bit different to me, because so far my world of robotics was filled with electronics like microcontrollers, stepper motors...blah..blah..

So I've decided to participate in that competition. Here it goes.

At first, there was a abstract selection of which the selected will be qualified to the next round of space configuration. Worked hard enough and mine got selected and this is how I made it.

Materials and tools used:

                                 Ply wood sheet, Aluminium sheet, Card board, glue, scissors, Nuts and bolts(4mm), wood plank(15"x15"), pencils, syringes(50ml,20ml,10ml), Cello-tape, threads.

Basic principle:  

 Pascal's law or the principle of transmission of fluid-pressure is a principle in fluid mechanics that states that pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure ratio (initial difference) remains the same

                    Our hydraulically actuated mechanical arm works on the principle of Pascal's law.where water is used as the hydraulic fluid and syringes as hydraulic cylinders.

Design abstract :

              I have been making, designing the hydraulic arm simultaneously, so by giving the images of each step makes us to prepare the abstract easily. we are sure that even if you skim through our images you can understand our abstract.

                     Our hydraulic arm is divided into four major components.

                                   they are,                 1)Base

                                                                   2)Stand

                                                                   3)Arm

                                                                   4)Gripper

let me describe each of them clearly,

Base:

                                           To support to entire arm, to make the arm rotate a base, which is wooden plank of dimensions (15"x15") is a perfect one. to that a hole of 1 cm diameter is made in the upper middle portion as shown in the figure. though it a nut and bolt is passed. 

Stand (height 12 inches):   

                              Stand is the component connecting Arm to the base it the component which bears the entire weight of the hydraulic arm. so to make it tougher and easy to work we choose Ply wood as the material. we cut it in to two similar shapes as shown in the figure

ARM:

To make the arm we have choosen aluminium as the material, since it is a lighter and tougher metal it is better. the arms are rectangles with holes drilled at the respective positions as shown in the figure. with the help of 4mm bolts it is fixed but not completely tightened to the stand. Through  the larger holes a wooden rod/pencil is passed which can held the two arms. A small wooden block of dimensions 2"x2" which is having a cylindrical hole of diameter of 2.5 cm is fixed in between the arms and fixed to them with the help of nails as shown in the figure.this wooden block holds the syringe (20 ml)  which operates the aluminium gripper holder.this wooden block is movable axially(taking  the nail as axis). 

Gripper:

   The gripper has two sub parts

1)outer body

2)gripper arm