robotics dredger

1. 3.4.4 Actuators
We used DC motors to actuate the pulleys. With the help of switches. We can
Move in both direction of the motors. A total of 3 DC motors are used for operation to
Carry out. Two DC motors are fitted at the bottom side of slider mechanism use to actuate
Pulley.
Motor-1
One motor is used for opening and closing of the grab. Opening and closing of
Grab mechanism is to collect the sludge in scoops and remove it to hull boats.
Motor-2
Another motor is used for vertical motion of the grab assembly. It lifts the scoops
From water surface in upward direction and vice versa. Also collecting grab in hull boats.
Motor-3
Third motor is for the horizontal motion of the slider assembly by belt and pulley
Mechanism. First motor should be operated during the vertical motion of grab assembly
Simultaneously with the second motor. An attempt is made to show all the motors in one
Fig. We used a battery to run DC motors.
3.4.5 Two Hull Boats
We aimed in placing the grab mechanism in the middle of the boat such that the
Stability of the boat won’t be affected during operation. For this purpose, we proposed to
Have two hull connected with some gap in between for the grab mechanism. These hulls
Are made up of plastic. The main aim to use of hull boat is stability increases and boats
Can’t be wobble during operation. Both boats are connected by using frame. Frame is
Made up of m.s.material L-shaped rod. Actual slider mechanism is directly placed on the

2. Frame. Due to frame and two hull boats assembly as shown in figure stability of hull
Boats increased to large extent. We connected the two hulls using aluminium rods so that
One of the two hulls won’t wobble during the operation. The two hulls connected with
Aluminium rods are shown in figure.
For extra stability of the system, we fixed a fixed a firm mild steel frame on the two hull
boats as shown in figure. Mild steel frame is painted after a coating with varnish to prevent it
from rusting.
3.5 DESIGN CALCULATIONS
3.5.1 Grab mechanism
We used simple grabbing mechanism for grab the sludge using pulleys and string.
Design of scoops:
Design procedure for scoops is as follows
Weight of material lifted by scoops:
Scoops is nothing but elliptical tank or cylinder.
Volume=𝐴 = 𝜋AB1
= π *11*12.5*1
= 5612.75 cm3

3. =5.612 litre
Total mass of water Hyacinths carrying by scoops:
Density of water hyacinth = 260 kg/m3
= 0.26 kg/litre
Mass = 5.612 * 0.26
= 1.45 kg
Scoope can carry 1.45 kg mass of water hyacinths at time
Weight of scoope:
Elliptical Area = πab
= π * 12.5 * 11
= 431.96 cm2
Volume = Elliptical Area * thickness
= 431.96 * 0.1
= 43.196 cm3
Rectangular area = length * width
= 5 * 7
= 35 cm2
Volume = 3.5 cm3
Curve area = 27 * 13
= 351 cm3
Volume = 35.1 cm3
Total volume = 2 * (43.196+3.5+35.1)
= 941.12 cm3

4. Weight of scoops = volume * density
= 941.12 * 7.860 * 1
= 1286.81 gm.
Force Analysis of Link
Overall mass of scoops = 1.3 kg
Force required to apply by each link to open the scoops
= 1.3 * 9.81 /2
= 6.37 N
Shear force calculation:
Bending moment calculation:
B.M. at B = 0

5. B .M. at A = 6.37 * 0.23
= 1.54 N-m
Dimension of link:
3.5.2 Selection of string
Tension on string in grabbing Mechanism
Tension on each string = 6.30 N
Dimension of string used
Diameter of string = 1 mm
Cross sectional area of string = π/4 * d2
= 0.785 mm2

6. Maximum Load Lift by the string = 49 N (5 kg)
Tensile strength of string = 49/0.785
= 62.42 N/mm2
Introducing Factor of safety = 3
Tensile strength = 62.42/3
= 20.80 N/mm2
Actual Tensile stress on each string = T/A
= 6.30/0.785
= 8.02 N/mm2
Since tensile stress is less than tensile strength of string.
8.02 < 20.80 ………Hence String is safe.
3.5.3 Tension in string in Lifting Mechanism
Total weight carried by string = 26.84 N
Total weight carried by each string = 13.42 N
= 13.42/0.785
= 17.09 N/mm2
Tensile strength = 20.80 N/mm2
Since tensile stress is less than tensile strength of string.
17.09 < 20.80
Hence string is safe.
3.5.4 Motor selection
Motor used for grabbing and lifting mechanism
Total weight which has to lift by the motor =

7. Weight of water hyacinth +weight of scope = 26.84 N
No. of motors = 2
Weight on each motors = 13.42 N
Diameter of pulley = 1 cm
Torque = tension in spring * radius of pulley
Tension in string = 13.42 N
= 1.36 kg
Torque = 1.36 * 0.5
= 0.6838kg-cm
 Specification of motors
Type: DC gear motor
Voltage: 12 volt
Speed: 10 rpm
Torque: 6 kg-cm (0.588 N-m)
3.5.5 Motor, pulley and Belt for sliding mechanism:
Total Load = total load hang by slider + weight of motor used
= 2.72 + 2 + (2 * 125)
= 2.72 + 0.25
= 3 kg
Specification of motors:
Type: DC motor
Voltage: 12 volt
Speed: 50 rpm

8. Torque: 1.4 kg-cm
Specification of pulley:
Dimension of pulley:
We used two pulley for sliding mechanism one at the motor shaft and another at
end of frame. Pulley
Length of belt
Belt is fitted on pulley. It is made of leather of 4 mm diameter.
Length of belt = 2 * distance between two pulleys + π d
= 2 * (58+ 58+35) + 3.14
= 305.14 cm
3.5.6 Designof Hulls
Dimension of hulls,
Height = 85 cm
Radius = 29 cm
Volume = ½ * π * 292 * 85

9. = 112231.45 cm2
Total volume of two Hulls = plastic
3.5.7 Dimension of frame
1. Base frame = 153 * 92
2. Vertical Frame = 153 * 66.5
Material for Frame = mild steel
3.6 System Manufacturing
Fabrication is a process of making components by cutting, bending and
Assembling. Fabrication is the extended phase in our project. After completing design of the
machine. We are in the process of doing fabrication and we will continue it in the further
semester. After designing all the components and selection of safety and measuring
instruments the next step is to fabrication work of the project.
Fabrication work is done at-
‘Sai’ Workshop
Yeola, dist-Nashik
3.6.1 Frame
 Material required
a. L-size c/s frame of the size 0.5” * 0.5” and length 153 cm (4 nos).

10. b. L-size c/s frame of the size 0.5” * 0.5” and length 66.5 cm (4 nos).
c. L-size c/s frame of the size 0.5” * 0.5” and length 92 cm (4 nos).
d. L-size c/s frame of the size 0.5” * 0.5” and length 153 cm (4 nos).
 Step followed to manufacture the frame
a. At first we are taken raw size L-size mild steel bar and cut them into above
required size by using cutter.
b. Then we finish the cutting edges by grinder and files.
c. Then we join the all angle frame to each other one by one using the welding
machine. We join this skeleton of the frame according to drawing means in the
prescribed fashion.
d. Join all part of the frame with help of welding machine after above welded part
smooth grinder done.
e. Here the manufacturing of frame is completed.
 Process sheet of frame
Table 1 process sheet for main frame
Sr.no Operation
description
Machine
used
Tool used Assembly
with
Time in
min.
1 marking scale By hand - 15
2 cutting Cutting
machine
Grinder
cutter
- 15
3 Welding Arc
welding
- Assembly
with frame
20
3.6.2 Scoops

11.  Material required
a. Sheet metal of size 50 cm * 30 cm
 Steps followed to manufacture the scoops
a. At first we take metal sheet of size 50 * 30 cm as raw material.
b. Cut them into required size by cutter
c. Marking is done as per the design on raw material and then cut the sheet metal.
d. Then we finish cutting edges by grinder and files.
e. Then for fitting of scoops into metal box drill is made at parts of scoops
f. Then we cut two parts of size 27 * 13 cm to joining of scoop
g. Then we join all parts as per design by welding process by using welding
machine
h. We used electric arc welding machine for this process.
i. After that finishing is done by smooth grinding machine.
j. Here the manufacturing of scoops is completed
 Process sheet of scoops
Table 2 process sheet for scoops
Sr.no Operation
description
Machine
used
Tool used Assembly
with
Time in
min.
1 marking scale By hand - 15
2 cutting Cutting
machine
Grinder
cutter
- 15
3 Welding Arc
welding
- Assembly
with frame
20
4 finishing Grinder Grnder 15
3.6.3 Links
 Material Required
a. Rectangular shape MS solid rod of 1cm * 2 mm of length 23 cm(4 nos).
b. Rectangular shape MS solid sheet of size 19cm * 7.5cm(1 nos).
c. Rectangular shape MS solid sheet of size 10cm * 6cm(1 nos).
d. Rectangular shape MS solid sheet of size 10cm * 2cm(2 nos).
e. Rectangular shape MS solid sheet of size 6cm * 2cm(1 nos).

12.  Steps followed to manufacturing the Link
a. First from raw material cut 2 rods
b. Two metal strips of size are made champer at ends.
c. For connecting links and surface chamfer and given the circular shape by
grinder.
d. For link 2 metal is cut in rectangular shape of size 1 * b and cut the centre
position
e. Grind finishing is done by using grinder.
f. As per the design metal strips are cut for manufacturing of link 2. These are
joined.
g. Electric arc welding.
h. After this finishing is done by grinder machine for both link 2 and link
3.Process sheet of links
Table 3 proceses sheet for links
Sr.no Operation
description
Machine
used
Tool used Assembly
with
Time in
min.
1 marking scale By hand - 15
2 Cutting Cutting
machine
Grinder
cutter
- 15
3 Welding Arc
welding
- Assembly
with frame
20
3.6.4 Slider
 Material required
a. Rectangular c/s aluminium hollow bar of size 4cm * 1.8 cm of length
26 cm (3 nos).
b. Rectangular c/s aluminium hollow bar of size 4cm * 1.8 cm of length
25 cm (3 nos).
 Steps followed to manufacture the slider
a. At first we take rectangular c/s aluminium hollow bar of size
4cm*1.8cm.

13. b. Three parts of same size cut by cutter.
c. Two parts of size cut by cutter
d. Then rectangular shape is formed from cut section of aluminium
bar by using screw.
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f. From the bottom side using pulleys are fixed as per design by using
screws.
g. Two motors are also fixed at opposite sides’ rectangular frame
formed by using screws and L-shaped rods.
h. Here the manufacturing of slider is completed.
,