MobiARM

8/21/2019 MobiARM

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MobiARM is not a toy.Robosoft Systems® employs high performance motors and

electronic equipment.Robosoft Systems® cannot be held liable for damages or injuriescaused by the improper or un recommended use of MobiARM.All advanced modifications or deviations from the directionscontained herein are considered to be at the risk of the MobiARMowner, and are not supported by Robosoft Systems®.

This is the MobiARM Owners Manual v1.00 for the robot MobiARM.For more information go to http:// www.robosoftsystems.co.inor contact us at [email protected] rights reserved.

Owner’s Manual

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Important Note

This manual refers to the product MobiARM. It can also be used in Robo-Bricks(a workshop conducted by Robosoft Systems®). All the shown compo-nents will not be available if the product is bought in parts. Nevertheless, youcan refer to the specific section as that of the parts that you have bought toknow the assembly details. The components shown in this manual may not be

the same as those in the packaging and may change without notice.Hereafter MobiARM will be referred to as“Robo Bricks” in the

manual to maintain compatibility with other products.For further details and supported accessories, please visit our website

http:/ / www.robosoftsystems.co.in/ roboshop.

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This symbol indicates that improper use can lead tophysical injury or damage to the robot itself. Iturges you to exercise precaution.

This symbol indicates that there is some additionalinformation or tip that you can use.

This symbol indicates that you should make a noteof the point.

Conventions

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Safety instructions 01

About us 02

Introduction 03

Bricks features 04

Robot overview 05

Package contents 06

Assembly 08

Know your board 52

Connections 54

Example 56

Frequently asked questions 57

Appendix A 60

Appendix B 63

Appendix C 68

Appendix D 72

Appendix E 76

Contents

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www.robosoftsystems.co.in

Safety Instructions

Be careful while using the screw driver, place the assembly on a

platform & then tighten the screw. Don‘t tighten the screw

keeping the assembly in your hands, the screw driver may slip

& you could injure yourself. In case of cuts and bruises, wash

your hands with water, apply antiseptic lotion and consult a

doctor immediately.

Don‘t work on your machine with wet hands, since there are

electronic parts in your machine & it depends on 230V mains

supply for operation there are chances of getting an electric

shock (It can cause severe injuries or loss of life)

The gear box is an electromechanical assembly which works

desirably when provided with appropriate supply please don‘t

try to move it forcefully with your hands as this can cause per-

manent damage.

The components on the two electronic circuits have soldered

joints on the bottom end which are vulnerable to short circuit.

To avoid such a situation do not place the circuits on conduct-

ing surface when the supply voltage is there, otherwise there

can be a short circuit between the soldered joints causing per-

manent damage.

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About Robosoft Systems®

Robosoft Systems ®is a young & dynamic organisation still in its nascent stage.

It all started with a vision back in 2008 when a group of young engineer‘s bitten by the

entrepreneurship bug came together for transforming their ideas into reality, & it had to be

the dynamic field of Robotics just like the young minds themselves.

Just one year into its inception & the company is creating waves in the field of

Educational & Industrial Robotics with a wide range of intriguing products. We at

Robosoft Systems® believe in passing on the good knowledge. With 70% of the countries

population being young generation, the future lies in the schools & colleges, hence we

have been conducting WORKSHOPS at schools & colleges all across INDIA many of

them in association with the most respected media organisation TIMES OF INDIA(NIE)

and one of the most prestigious Technical Institutes in the world IIT Bombay .The

WORKSHOPS have become an instant hit since it provides the students the ultimate stagefor understanding science to its core concepts & going beyond the limits of textbooks.

On the technical front the company has had path breaking success lead by a

dedicated team of R&D engineers. The company has been launching products defying

cutting edge technology. This pursuit of excellence has won the company many accolades.

Recently the company entered into a joint venture with SOLARBOTICS®CANADA, a

company which deals in high end SOLAR BOTS.

Managing Partner

Robosoft Systems®

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Introduction

This manual has been written keeping in mind robotic enthusiasts from all

age groups. It will take you right through the building steps of the Robo Bricks to con-

trolling it.

Robo Bricks is a basic level robot from Robosoft Systems®. It helps you to

get a feel of what robotics is all about. Robo Bricks has been developed by bringing to-

gether the laws & concepts of Physics, Electronics & Mechanics hence it helps one to

inherit this knowledge as one is implementing it.

Robo Bricks is basically a manually controlled wired robot which uses Cat-

erpillar type track belt locomotion. I t is quite evident from the name that it will be used

for dumping purpose; therefore it has a bucket which is lifted with the help of a gear box.

The gear box is dominantly a mechanical assembly which uses different types of gears viz.Worm gear, Spur gear. Robo Bricks is rear wheel driven wherein two DC motors of 12V,

45 r.p.m. rating are used, a third motor is used in the gear box which is a 12V, 60 r.p.m.

motor. The motors used here are high Torque motors. On the electronics front this ro-

bot has two modules first being the PCB which is used in the Sandwiched Joystick & the

second one is the main board or the motor driver module which will be enclosed in the

main body of the Robo Bricks.

Statutory Warning:

This is a highly addictive robotics kit; please doyour school homework before starting.

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Bricks Features

Strong metal chassis

Pick & Place Robot

Track & Belt type locomotion

Added Accessories : 12V Adaptor, CD, FRC Cable

Attractive LED Joystick

Capability to drive 4 motors simultaneously

Provision for battery powered operation

Ready ADD-ON‘s available for modifying the robot

Can be easily up graded to a wireless machine

High gear ratio in the gear box

Locking of gear box due to one side transmission

User friendly control interface

Nylon gears for longer durability

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Robot Overview

All the diagrams in this manual arenon-scaled and have been provided forrepresentational purposes only. Do nottry to imitate the diagrams for any useother than referring to them.

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Package contents

X 1

X 88

X 2

X 4

X 4

X 11

X 8

X 18

X 7

X 2

X 8

X 4

X 4

X 4

X 2

X 3

X 2

X 2

X 3

X 10

X 52

X 52

X 2

X 4

X 1

X 1

X 1

X 1

X 1 X1

X1

X 4

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X2

X2

X1

X1

X1

X2 X2

X2

X2

X2

X4

X4

X4

X4

X4

X4

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Side Plate Assembly

Let us identify the parts that you will need to make the base frame.

4X6mm Screws X 12 Lugs X 6

218X60mm side plates X 2

All you kids out there, please don‘t get over-excited while using the screw driver.

Although it doesn‘t seem to be a hazardous job but there is a possibility that you

may end up sticking band aids on your fingers if you don‘t obey our instructions.

Please refer the Safety & handling section on page --- for tips on how to use a screw

driver.

Step 1

Screwdriver

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Fix the lugs on one of the side plates with the help of 4X6 screws as shown inthe figure.

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Hooray! You are now done with the first plate. You will now have to do exactly the

same with the second plate! After you have finished with the second plate, you will

now have two plates with lugs fitted to both of them.

Before you start with the next part, please ensure that all the screws are not fully

tightened. They must all be at least one round loose.

As Humans we have a tendency of tightening the screws completely, & that is quite

normal but in this case please be a bit abnormal & don‘t tighten the screws

completely, tighten them only up to 70-80%. Otherwise you will face problems later

on, this is because the Robo Bricks is dominantly a mechanical assembly hence there

should be some margin for movement for the screws.

Attach the lugs to the plate one by one. Do not try to attach all of them at once.

While attaching the lugs, keep the lug laid on a table (not asstanding as shown in

the above diagram) and place the plate on it in such a way that the holes on the plate

match exactly with the holes on the lug. Then hold a screw above the hole exactly

perpendicular with one hand & tighten the screw with a screw driver with the other

hand & you will see that the screw will head straight into the lug. This is a very handy

tip; please follow it religiously so that you don‘t have to sweat out tightening the

screws.

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Base Assembly

Now that you have finished with the first step, we will move on, i.e. fixing the 2

side and front plates to the base plates. Let us first identify the parts that you will

require in addition to the parts that were required in the first step.

218X150mm bottom plates X 1

Please note that the plates that we have used till now are all provided to you in

pairs. They look the same and you can use them in any order that you want. It does

not matter which plate you are using, as long as you use the specific size of plate

which we are telling you to.

Step 2

4X6mm Screws X 14

Screwdriver

150X60mm

front and

back plates

X 2

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Fix the lugs onto the side plates with the help of 4X6 screws as shown in thefigure.

N o t i c e t h e t w o b i g g e r h o l e s o n t h e t w o

e n d s o f t h e s i d e p l a t e s ; o n e i s o v a l i n

s h a p e & t h

e o t h e r o n e i s c i r c u l a r i n s h

a p e . M a k e s u r e t h a t t h e o v a l h o l e i s

f a c i n g t h e o v a l & c i r c u l a r h o l e i s f a c i n

g t h e c i r c u l a r h o l e a s s h o w n b e s i d e .

T h e f o u r h o

l e s o n t h e b a s e p l a t e m u s t c o m e o n t h e s i d e w h e r e t h e r e a r e c i r c u l a r

h o l e s .

Fig 1

Fig 2

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R e m e m b e r n o t t o

t i g h t e n t h e s c r e w s f u l l y !

Fig 3

Fig 4

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Step 3

Motor and Dead Axle Mounting

Now we will have to mount the dead axle and the motor to the base assembly that

you have just made. Below is the list of components that you will need to complete

this step.

DC Motor 45RPM X 2

Dead

Axle X 2

20-22 Spanners X 1

14mm

Nut X 4

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Metal bushings have been provided for proper grip of the motor. An extra lug has also

been provided in case you need one.

These bushings will help to protect the 45RPM motor shafts from breaking under ex-

cessive load. Please use them to mount the motor on the rectangular chassis of your

robot. The bushings will comein betweenthe metal box and the motor itself.

Please note thatYOU WILL NOT USE THE SPANNER TO TIGHTEN THE

MOTOR NUTS.

The wheel should gocompletely inside the shaft of the motor! For reference you can

use the previous diagram in which you can see the hole of the motor shaft even after

the wheel has been mounted.

Thehole on the shaft of any of the motors hasno significanceat all.Do not try to

match the holes on the steel rims of the wheels with the holes on the shaft of the

motors.

The wheels are mounted on the motor shaft with the help of 4X8 mm screws. Ensure

that you tighten the screws only up to the point where the motor starts to make a

little noise on rotating the wheel by the hand.

The wheels which are to be mounted on the dead axle have to be fixed with the help

of e-clips andnot the screws .

Do you remember that we mentioned earlier, thatthe oval holes on the metal side

plates must face each other? The reason for this is that the motor will be mounted

through these oval holes. Later if we require to vary the distance between the front

and rear tyres, we can easily do that by unscrewing the motor nut and sliding the

motor in either direction.

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You will now have to fix the dead axles to the base. Below we have shown how to

N o t i c e h o w y o u h a v e t o p u t t h e d e a d a x l e s . T h e y e l l o w h e a d o f t h e d e a d a

x l e s w i l l b e

o n t h e i n s i d e o f t h e r e c t a n g u l a r m e t a l l i c b o

x f a c i n g e a c h o t h e r .

Fig 1

Fig 2

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Fig 3

Fig 4

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Y o u h a v e t o i n s e r t t h e m o t o r s f r o m t h e i n

s i d e o f t h e r e c t a n g u l a r b o x , i n s u c h a w a y t h a t t h e

s h a f t a n d t h e t h r e a d i n g o f t h e m o t o r s p r o t

r u d e o u t t h r o u g h t h e o v a l h o l e s o f t h e b o x . W h y

d o w e n e e d

t h e s h a f t o f t h e m o t o r & d e a d

a x l e t o b e o u t o f t h e b o x ? W e l l , w e w a n t t o m o u n t

t h e t y r e s o n

t h e m o t o r s h a f t , d o n ‘ t w e ?

Fig 5

Fig 6

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Y o u W I L L N O T t i g h t e n t h e n u t s o n t h e m o t o r a x l e u s i n g t h e s p a n n e r .

Y o u w i l l o n l y u s e

y o u r h a n d s t o t i g h t e n t h e n u t s . Y o u w i l l f i x

t h e m o t o r s o n l y t h r o u g h t h e o v a l h o l e s a n d N O T

t h r o u g h t h

e c i r c u l a r h o l e s . D o n o t o v e r t i g h t e n t h e n u t s o n t h e m o t o r t h r e a d .

Fig 7

Fig 8

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Step 4

Mounting the tyres onto the dead axle and the motors are very easy, but first of all we

must know what we will require to complete this step.

Wheels X 4

E-Clip X 2 4X8 mm screws X 2

Screwdriver

Nose Pliers

You will need the nose pliers only to fix the e-clip. Where do you use the e-clip? Well,

to fix the tyre on the dead axle, we cannot use screw, so we use the e-clip to fix the tyre

to the dead axle.

Wheel Mounting

Among the components shown above, you will have to find a pair of nose pliers for

yourself. It isnot included in the kit. If you don‘t have one, just take the robot and the

two wheels to any local hardware shop who will fix the tyre to the dead axle along with

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Fig 1

Fig 2

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Step 5

Chain Assembly

Now that you have completed with assembling of the base, we will start to assemble

the chain. To complete this step you would need the following components.

Chain Link X 52 Dawble Pin X 52

The steps to build the chain are shown below. You have to insert the smaller end of a

link into the larger end of another link and insert a dawble pin through the holes as

shown below.

Fig 1 Fig 2

Fig 3

Fig 4

Fig 1

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Fig 5

Fig 6

Fig 7

Fig 8

Fig 9

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Note how the links approach each other. Refer to fig 1.

After the holes on the links get merged & aligned with each other, the dawble pin has to be inserted. Refer to fig 2.

Refer to fig 3 and 4 for a final view of the links of the chain after you have inserted the dawble pins.

There are only26 linksin one chain.Do not connect more than 26 links in one chain.

Do notmake a loop once you have connected 26 links. That is, do not connect the first and last links ofthe chain.

Turn overleaf for a graphical overview of the steps to mount the chain on the wheels.

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Step 6

Gear Box Assembly

You have now finished with the base of the robot. We will now start building the gear

box and for this, you need to keep aside whatever you have built till now. First of all

we need to identify the components that we need now.

70X60mm gear

box motor

loading plates X

2

70X60mm gear

box worm

wheel loading

plates X 220-22 Spanner

Lugs X 6

Screwdriver

Dead

Axle X 2 DC Motor 60 RPM X 1

Worm

wheelWorm

gear

Worm wheel

shaft

4X6

mm

Screws

X 16

3X12

mm

Screws

X 1

Bushing X 2

Grub

screw

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Below we have listed the steps which you need to follow to complete the gearbox

assembly.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

W h e n y o u a t t a c

h t h e l u g s t o t h e g e a r b o x p l a t e s , y o u h a v e t o k e e p i n m i n d t h a t

t h e n o t c h e s i n

t h e p l a t e s s h o u

l d a p p e a r o n t h e s a m e s i d e . Y o u w o u l d a l s o h a v e t o t a k e c a r e t h a t t h e g r u b

s c r e w s h o u l d n o t b e o v e r t i g h t e n e d , o t h e r w i s e

t h e t h r e a d i n g i n t h e w o r m g e a

r h o l e m a y g e t

d a m a g e d .

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Fig. 7

Fig. 8

Fig. 9

Fig. 10

Fig. 11 Fig. 12

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Fig. 13 Fig. 14 Fig. 15 Fig. 16

Fig. 17Fig. 18

Fig. 19

Fig. 20

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In the first two diagrams the points to be noted are that the lugs are on the lower end of

the plates so that the holes with the notch are on the upper end. Make sure that the

screws are fixed uniformly i.e. if in one lug the 2 screws are fixed in the lower holes of

the metal plates, then in the screws on adjacent lug should also be fixed in the same

holes. Observe that after putting the plates together, the notches of the holes should

face the same direction. Refer to Fig. 12 to understand it properly.

Observe the Fig. 6 in which the worm gear is mounted on the shaft of the motor. The

hole on the shaft of the motor has nothing to do with the hole on the worm gear. Justinsert the worm gear fully on the shaft of the motor, and then take the grub screw and

insert it in the worm gear as shown in the Fig. 6. The grub screw should be tightened

only up to the limit at which the motor makes a noise when the worm gear is rotated.

In this section we are mounting the worm wheel also known as the Spur gear.

Fig 13. As you can see in the figure, here we are inserting the spur gear in the shaft

provided for it, here one needs to be careful. As seen in the fig the spur gear has a small

rim coming out on its right side, this rim is having a small hole for a screw. Likewise

there is a hole for a screw on the shaft which is slightly offset from the centre. Now

hold the shaft in your right hand such that centre hole is on the right side & hold the

spur gear in your left hand such that the rim is on the right side, now insert the shaft

into the spur gear from the side of the rim such that the centre hole on the shaft is

exactly aligned with the hole on the rim of spur gear.

Fig 15. Once there is proper alignment between the two holes insert the 3x12mm

screw in the holes, try to insert the screw fully into the two holes as shown in Fig.16. This could be a little difficult, place the assembly on a platform & try to apply proper

perpendicular pressure while tightening the screw. It is not necessary that the screw

should go in completely, the primary requirement is that the spur gear should hold the

shaft properly & it should not slip even if you try to.

Fig 16. Before placing the shaft in the gear please make sure that the spur gear is

exactly in the centre of the shaft & not offset, if that is the case follow the instructions

again.

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Step 7

Arm Assembly

Now we will construct the arm for our gear box, one end of this arm will be attached

to the gear box & the other end will hold our bucket. This is slightly critical so you

have to be attentive. Gather the following parts in required quantity to build the arm.

3mmnutsX 4

3X12mm

screwsX 6

Side plates forarm X 2

Before you mount the couplings on the arm plates you have to un-

derstand that there are two angles on the platesα andβ. The rela-

tion betweenα andβ is

α < β While you attach the arm plates to the gear box, you have to take care that

I.β will face downwards when the arm is in front of the gearbox.

II. This implies that the notch will face forwards on both sides of the gearbox.

III. Forward indicates the side where there is the dead axle on the gear box.

When you attach the couplings to the arm plates, you have to consider these

things and attach them as shown in the page beside.

CouplingsX 2

Gearbox

Screwdriver

α β

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Our robot has two arms just like us, & both our arms are identical so should ourrobot have, to achieve this we need to fix the coupling in an appropriate manner.

Fig. 1 Fig. 2 Fig. 3

Fig. 4

Fig. 5

Fig. 6

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Step 8

Gripper Assembly

Finally a relief for you, a very easy part to assemble. But don‘t loosen up now we are

quite close to complete our machine. Let us identify the essential components required

for building our gripper.

Worm

wheel X

3

4X6 mm

Screws X

20

4 mm nuts

X 4

Screwdriver

White

spacers X 4

12 mm

metal

spacers X 4

30 mm

metal

spacers X 4

Oval plates

X 4

Flat plates

X 4

Worm gear

X 1

Main plates

X 2

Arm X 2

U plate

X 1

14 mm

nut X 1

Taperedscrew X 4

12V DC

Motor 60

RPM X 1

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Now insert the motor in the U plate as shown in the figure below. The shaft of themotor has to be inserted completely in the hole which is there in the U plate.

O n c e y o u h a v

e i n s e r t e d t h e m o t o r , t h a n f r o m

t h e o t h e r e n d y o u c a n p l a c e a

4 m m n u t o n t h e

s h a f t & h o l d i t o v e r t h e r e w i t h o n e h a n d & r o

t a t e t h e m o t o r w i t h o t h e r h a n d

s u c h t h a t t h e n u t

g e t s t i g h t e n e d

i n t h e t h r e a d i n g p r o v i d e d o n

t h e s h a f t o f t h e m o t o r . Y o u w o u l d b e a b l e t o

t i g h t e n t h e m o

t o r o n l y u p t o a c e r t a i n l i m i t a f t

e r w h i c h i t b e c o m e s i m p o s s i b l e

t o f u r t h e r t i g h t e n

i t , n o w y o u c a n t a k e a s p a n n e r . I n s e r t t h e b i g g e r j a w o f t h e s p a n n e r i n t h e U p

l a t e f r o m r i g h t o r

l e f t s u c h t h a t

i t h o l d s t h e n u t , t h a n y o u c a n r o t a t e t h e m o t o r w i t h t h e o t h e r h a n d t o t i g h t e n i t

s u f f i c i e n t l y .

Fig. 1

Fig. 2

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Fig. 3 Fig. 4

Fig. 5 Fig. 6

Fig. 7 Fig. 8

T o t i g h t e n t h e g r u b s c r e w p r o p e r l y & e a s i l y r o t a t

e t h e w o r m g e a r s u c h t h a t t h e h

o l e i n t h e w o r m g e a r i s f a c i n g

e i t h e r t h e r i g h t o

r l e f t s i d e , w h e r e t h e r e i s n o m e t a l p l a t e .

D o n o t o v e r t i g h t e n t h e g r u b s c r e w , o t h e r w i s e y o u

m a y d a m a g e t h e w o r m g e a r

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Fig. 9

Fig. 12

Fig. 10

Fig. 11

Fig. 13

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W h e n y o u i n s e r t t h e s p u r g e a r s t h e t e e t h o n t h e s p u r g e a r g e t s e n g a g e d w i t h t h e t e e t h ‘ s o n t h e w o r m g e a r .

W h e n y o u a r e

i n s e r t i n g t h e s p u r g e a r s m a k

e s u r e t h a t b o t h t h e s p u r g e a r s a

r e i n s e r t e d j u s t i n t h e s a m e w a y

a s s h o w n a b o v e . P

l e a s e n o t e

t h a t t h e a n g l e o f t h e s p u r g e a r i s c r i t i c a l , i f t h a t i s n o t m a i n

t a i n e d t h a n o n e w i l l f a c e p r o b l e

m s w h i l e e n c l o s i n g t h e g r i p -

p e r . T

h e a n g l e s o f t h e s p u r g e a r w i t h r e s p e c t t o t h e w o r m g e a r i s r o u g h l y a r o u n d 4 5 ° .

B e f o r e c l o s i n g t h e g r i p p e r w

i t h t h e t o p p l a t e p l e a s e m a k e s u

r e t h a t t h e s p u r g e a r s a r e p l a c e d

p r o p e r l y a s e x p l a i n e d t o y o u

p r e v i o u s l y . I f

t h e y a r e n o t h a v i n g p r o p e r o r i e n t a t i o n t h a n p l e a s e d o t h e c o r r e c t i o n b e f o r e p r o c e e d i n g .

T o f i x t h e o v a l p l a t e t o t h e

s p u r g e a r , y o u h a v e t o u s e t h e

t a p e r e d s c r e w s . Y o u w i l l n o t i c e t h a t t h e r e a r e h o l e s o n t h e

w o r m w h e e l . T h e b i g g e r h o

l e o n t h e p l a t e s h o u l d g o i n s i d e

t h e p l a s t i c p r o j e c t i o n o f t h e s p u r g e a r a n d o n e o f t h e h o l e s

o n t h e w o r m w h e e l h a s t o b

e m a t c h e d w i t h t h e s m a l l h o l e o

n t h e p l a t e .

Fig. 14

Fig. 15

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T a k e o n e a r m o f

t h e g r i p p e r & t w o s m a l l m e t a l

c y l i n d e r s . T h e s e c y l i n d e r s h a v e

t o b e i n s e r t e d i n t h e h o l e s

w h i c h a r e t h e r e i n t h e a r m s a s s h o w n .

F i x t h e a r m s t o t h e g r i p p e r a s s h o w n .

T a k

e t h e a r m c a r e f u l l y & i n s e r t

i t i n t h e o v a l & f l a t p l a t e s u c h t h a t t h e s m a l l c y l i n

d e r s i n t h e a r m d o e s n ' t f a l l o f f .

Y o u h a v e t o i n s e r t t h e a r m

s u c h t h a t t h e h o l e o n t h e e d g e o f t h e a r m s h o u l d

a l i g n w i t h t h e h o l e i n t h e o v a l p l a t e & t h e h o l e a t t h e c e n t e r

o f t h e a r m s h o u l d

a l i g n w i t h t h e h o l e i n t h e f l a t p l a t e .

Fig. 16

Fig. 18

Fig. 19

Fig. 17

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O n c e a g a i n p l e a s e s e e t h e o r i e n t a t i o n o f t h e a r m s , b o t h t h e a r m s a r e m i r r o r i m a g e s o f e a c h o t h e r .

A t a n y p o i n t o f t i m e

t h e o r i e n t a t i o n o f o n e a r m

i s e x a c t l y s i m i l a r t o t h e o t h e r , i t

i s n o t t h a t o n e a r m i s s t r e t c h e d

& t h e o t h e r a r m i s f o l d e d ,

t o

a c h i e v e t h i s y o u w i l l h a v e

t o b e c a r e f u l w h i l e m o u n t i n g t h

e s p u r g e a r s & f i x i n g t h e a r m s .

I f y o u r g r i p p e r l o o k s l i k e t h i s

t h a n i t b r i n g u s t o t h e e n d o f c o n s t r u c t i n g o u r g r i p p e r .

T h i s w a s b y f a r t h e m o s t i n t e r

e s t i n g s t e p i n t e r m s o f b o t h

b u i l d i n g y o u r r o b o t & l e a r n

i n g . I t g i v e s y o u a n e s s e n c e o f w

h a t i f f e e l s l i k e t o b e a m e c h a n i c a l e n g i n e e r .

Again the gripper is a small assembly hence children‘s

may hold it while tightening the screws, please don‘t do

this mistake if the screw driver slips it may hurt you. So

keep the assembly on a platform & then tighten the

screws.

Fig. 20

Fig. 21

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Gear Box and Top Plate Assembly

Gear Box Assembly

Now that we have built one of the most complex part of our robot, the gear box lets

put it t work. You will require the following parts to assemble the gear box .

Do you remember the 4 holes in square geometry which we were talking about? We will use

those holes now. We will fix the gear box firmly on the top plate by screwing it in the 4

holes.

4X6mm

Screws X 14

Screwdriver218X150 mm top plate

Step 9

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Fig. 1

Fig. 2

O b s e r v e t h e

f i g 1 i n t h e p r e v i o u s p a g e y o u

w i l l g e t a n i d e a o n h o w t o f i x t h e g e a r b o x o n t h e t o p p l a t e .

W h e n y o u a r e p l a c i n g t h e g e a r b o x m a k e s u r e t h a t t h e m o t o r b o d y i s f a c i n g

t h e o v a l s l o t o n t h e t o p p l a t e

& t h e f r o n t p a r t o f t h e g e a r b o x h a v i n g t h e d e a d a x l e & t h e a r m a r e f a c i n g t h e o p p o s i t e d i r e c t i o n . N o w t o

f i x t h e g e a r b o x t u r n o v e r t h e a s s e m b l y o f t h e t o p p l a t e & t h e g e a r b o x s u c h t h a t y o u c a n s e e t h e o t h e r

s i d e o f t h e p l a t e , n o w t r y t o a l i g n t h e 4 h o l e s o n t h e t o p p l a t e w i t h h o l e s

o n t h e p l a s t i c l u g s w h i c h a r e

t h e r e i n s i d e t h e g e a r b o x h o l d i n g i t t o g e t h e r .

N o w t a k e 4 s c r e w s & t i g h t e n t h e m t h r o u g h t h e h o l e s i n t h e

p l a t e & t h e l u g s .

T h i s

t i m e I w o n ‘ t t e s t y o u r p a t i e n c e

f r i e n d s y o u c a n g o o n & t i g h t e n t h e s c r e w s 1 0 0 % .

B u t d o n ‘ t

o v e r t i g h t e n

t h e s c r e w s .

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Step 10

To complete the arm and the bucket assembly, you would need the following two

components; the bucket and the gearbox assembly which is affixed to the top plate.

Arm and gripper assembly

Gear box affixed to top plate4X6 mm Screws X 4

4 mm nuts X 4

Screwdriver

Gripper assembly

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T o f i x t h e g r i p p e r w e w i l l r e q u i r e f o u r 4 x 6 m m s c r e w s & 4

m m n u t s .

T a k e o n e s c r e w a t a

t i m e & i n s e r t i t i n t h e h o l e s

f r o m t h e o u t s i d e , n o w h o l d

t h i s s c r e w w i t h o n e a r m & d r i v e a n u t o n t h e s c r e w f r o m t h e i n s i d e a s s h o w n i n t h e a b o v e

f i g .

Y o u w o n ‘ t b e a b l e t o t i g h t e n t h e s c r e w & n u t c o m p l e t e

l y w i t h t h e h e l p o f a s c r e w d r i v e r , a l s o u s e t h e s m a l l s p a n n e r

p r o v i d e d . H o l d t h e n u t w i t h

t h e s p a n n e r t h a n t i g h t e n t h e s c r e w m o d e r a t e l y .

Fig. 1

Fig. 2

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Step 11

Circuit board and base plate assembly

The electronic circuits provided to you in this kit are all finished boards & you need not

change any thing in its. Just gather the following parts to move one step closer towards

completing your robot.

Base PCB

Base metal box

3mmnutsX 4

Screwdriver

3X12mmscrewsX 4

3 mm

spacersX 4

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Basically in this section we have to mount the PCB inside the rectangular box.

Fig 1 Fig 2

Fig 3

T o f i x t h e P C B i n s i d e t h e

m e t a l c h a s s i s w e r e q u i r e s c r e w s , n u t s &

w h i t e c o l o u r p l a s t i c s p a c e r s .

A s y o u c a n s e e i n t h e a b o v e d i a g r a m s

f i r s t c o m e s t h e n u t f r o m b e l o w a f t e r w h i c h t h e p l a s t i c s p

a c e r s a r e

p l a c e d .

O n t h e s p a c e r s t h e P C B i s m o u n t e d . N o w t h e 3 m m n u t s

a r e w o u n d o n t h e s c r e w s t o f i x t h e P C B t o t h e r e c t a n g u l a r

c h a s s i s .

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Joystick assembly

Done with fixing the PCB eh? What else do you think is remaining? How will you

drive the machine? You would need some kind of a steering, right? This is what we call

a joystick, which is what we are going to make! But, as usual, we need to identify the

components that we need to complete this step.

Bottom Acrylic Plate X 1 Top Acrylic Plate X 1 Printed Circuit Board X 1

Hexagonal

Spacer X 4

3 mm circular

spacer X 4

3X6mm Screw

X 4

3X8mm

Screws X 4

Switch cap X 8

Step 12

Screwdriver

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Fig 1 Fig 2

Fig 3 Fig 4

O n c e t h e b u t t o n s a r e p l a c e d o n t h e s w i t c h e s w e a r e n o w a p p r o a c h i n g t o w a r d s f i n i s h i n

g t h i s j o b . N o w t h e l a s t t h i n g

t o b e f i x e d i s t h e t o p

a c r y l i c p l a t e w h i c h a g a i n i s t r a n

s p a r e n t . O b s e r v e t h e p l a t e c a r e

f u l l y & y o u w i l l s e e t h a t i t i s

h a v i n g c u t s l o t s o n i t

f o r t h e b u t t o n s , F R C c o n n e c t o r & t h e 1 2 V D C a d a p t o r . P l a c

e t h e p l a t e o n t h e h e x a g o n a l

m e t a l s p a c e r s s u c h t h

a t t h e c a s t o n t h e p l a t e i s m a t c

h i n g w i t h c o m p o n e n t s o n t h e j o y s t i c k P C B .

N o w t a k e f o u r

s c r e w s & t i g h t e n t h e m

t h r o u g h t h e t o p p l a t e & t h e h e x a g o n a l s p a c e r s . D o n o t o v e r t i g h t e n a n y o f t h e s c r e w s a s

t h i s w o u l d l e a d t o t h

e a c r y l i c p l a t e s g e t t i n g c r a c k e d .

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Step 13

Motor connection and final assembly

Hooray! We have reached the final stage of our robot building! Just two more small

steps and your Robo Bricks will be ready to rock. So, without any more ado, let us see

what we need to complete this step.

4X6 mm screws X 6

Screwdriver

FRC cable

Arm & bucket assembly

Base assembly

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Fig 1

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To fix the top cover of your machine, you have to use six 4X6mm screws. After you have fixed

the screws you can now connect the FRC cable to your joystick and connect it to the power

source which will make your machine to run.

When you fix the screws, fix them in the diagonal order. That is fix the screws at

the diagonal ends and then after you have fixed the diagonal screws you have to fix

the screws at the sides of the top plate. After you have connected all the six screws,

you can tighten them up.

At this point, your robot building is complete! Before you can proceed to run the

Robo Bricks, please spare a minute and tighten all the screws that you have

connected to the machine, fully.But please take care not to over tighten them!

In the later sections, we have provided a detailed overview of how to connect the

motors and the joystick together. Please refer to the sectionCONNECTIONS if

you have any doubt about motor connections.

Fig 2

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Step 16

Now that we have taken all the pain to build our beast its time to take a test drive, but

for that we need to provide power to our machine. We would require the following

accessories to do the same.

Although there is provision for battery operation but the battery is not a part of the kit , you

have been provided with a 12V DC adaptor. Now the job of the adaptor is to provide a low

voltage which is required for the machine. In normal house hold supply points the voltage

is a whopping 230V AC which could easily burn our machine, hence to transform this to the

required 12V DC we need the adaptor .

Powering the joystick

Joystick assembly12 V DC Adapter

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Fig 1

Fig 2

T h e f i g u r e s c l e a r l y s h o w s h o w t o m a k e t h e c

o n n e c t i o n s b e t w e e n t h e j o y s t i c k

& t h e a d a p t o r . Y o u r j o y s t i c k

P C B c o n s i s t s o f a m a l e c o n n e c t e r a l s o k n o w n a s t h e 1 2 V j a c k & t h e a d a p t o r h a s a f e m a l e c o n n e c t o r a t

o n e e n d w h i c h i s t o b e i n s e r t e d t h e 1 2 V j a c k o n t h e P C B a s s h o w n i n t h e f i g b e l o w .

A s s o o n a s t h e

c o n n e c t o r i s

i n s e r t e d t h e L E D j u s t n e x t t o t h e j a c k w i l l g l o w g i v i n g a n i n d i c a t i o n t h a t t h e P C B i s g e t t i n g

t h e r e q u i r e d

p o w e r .

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Joystick PCB

Push Button Switch LED

FRC Connector 12V DC Adapter

Know your board

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Note: There is an important relation between the labelling (A,B....G) on the two

electronic boards. Suppose if you want to move your bucket up by pressing the

button ―D‖ on the joystick & bring the bucket down by pressing ―E‖. Then you

should fix RED wire of the gear box motor in the connector ―D‖ on the main board

& connect black wire with the connector labelled ―E‖ on the main board.

Mainboard PCB

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Before making the connections let‘s first understand the construction of the joystick as to why

we have made it the way it looks.

BC

D E

GF

A H

If you observe the joystick you will find eight push button switches on it. These switches have

been clubbed together in pairs of two i.e. switch A & B are close to each other similarly C &D,

E & F and G & H. There is a good reason behind it, as you must be knowing that a motor can

rotate in two directions either clockwise or anti clockwise, hence pressing one of the paired

switch will move the motor clockwise & the other switch will move it in anti clockwise direc-

tion. Since for achieving forward & backward movement one needs to press two switches, the

switches A, B, G & H have been placed such that it becomes easy to move forward & backward.

The switches C, D, E & F have been specially placed for controlling the bucket, any two of the

above switches can be used & the remaining two switches can be used in the future.

Connections

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There are six different kinds of motions in your machine, viz.

1. Forward movement

2. Backward movement

3. Taking a Right turn

4. Taking a Left turn

5. Lifting the bucket up

6. Moving the bucket down

In order to achieve forward movement the primary requirement is that both the wheels should

move in the forward direction, hence we have to move both the motors at the same time which

implies that one has to press two switches for going forward similarly for moving backwards we

have to press two switches.

There are two kinds of turns, viz.

Simple turn: For a simple turn only one motor is required to work hence you require to press

only one button for taking a simple turn for e.g. when right motor is working & left motor is idle

than your machine takes a left turn, yes you have read it correct its vice-versa it actually takes a

left turn.

Taking a turn across the AXIS of the machine: For this kind of turn both the motors are

required to work but in the opposite directions, hence you have to press two buttons for e.g.

when the right motor is moving forward & left motor is moving backward the machine will take

a quick left turn at the position where it is standing.

Only one motor is required to move the bucket up or down, hence we will use two switches, one

to move the bucket up & second to move the bucket down.

Right and Left Turn

Forward & Backward Movement

Moving Bucket Up & Down

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1. Connect the RED wire of the left motor in ―B‖ & black wire in ―A‖.

2. Connect the RED wire of the right motor in ―H‖ & black wire in ―G‖.

3. Connect the RED wire of the motor in the gear box with ―C‖ & black wire with

―D‖. So when you press ―C‖ the bucket will move up & when you press ―D‖ it comes

down.

A

D E

G

F C

B H

Example

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After lifting to a certain position the bucket is not moving up or the bucket is falling.

Why?

Check the worm gear & spur gear assembly inside the gear box. This problem is probably be-

cause these two gears are slipping and not holding each other. Follow the gear box assembly

instructions on page 42.

The Bucket is locked at one position & it is not moving at all ! Why?

Again check the gear box. This problem is probably due to the jamming of the worm gear &

spur gear into each other. Follow the gear box assembly instructions on page 25.

The machine is not moving at all but the motors are making noise & the motor shaft is

rotating! Why?

This means that the wheels are not holding the shaft of the motor tightly. You must remove the

chain from the wheels & than tighten the screw on the wheel.

The machine is not responding to any button pressed on the joystick! What do I do?

Please make sure that you have connected the 12V adaptor to the joystick & the RED

coloured power LED is glowing. This LED is an indicator that the joystick is getting power

supply. See that you have properly connected the FRC cable on both the joystick and the square

PCB.

The machine is not going forward & backward! What happened?Make sure that the wires of the motors are fixed properly in the connectors on the main board.

See that you are pressing the correct buttons for getting the forward or backward movements.

Check whether the FRC cable is proper or not; if there are any cuts on the cable then it is per-

manently damaged & needs to be replaced.

The Bucket is not lifting at all! What went wrong?

Check if the worm gear is holding the shaft of the motor properly. If the grub screw is not

tightened properly the worm gear will slip on the shaft.

Frequently asked questiions

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The machine is not travelling in a straight path; it deviates! Why? You have been provided with 3 motors in this kit, out of which 2 motors are 45r.p.m & one mo-

tor is 60 r.p.m. Please make sure that you haven‘t interchanged the 45 & 60 r.p.m motors. The 45

r.p.m motors are meant for the wheels & 60 r.p.m for the gear box. If they are interchanged than

the machine will not move straight.

Sometimes this problem also arises due to the tightening of chain on one of the wheels, verify

that the belt or chain on any of the wheels are not tightened fully, otherwise the machine will not

be able to move straight.

When I press a specific button on the joystick, the motor which is connected to that but-

ton doesn’t operate! What might have gone wrong?

The buttons that have been provided on the joystick may go bad after prolonged use. They may

either make contact continuously (sticking) or not at all (dead). If that is the case, you may iden-

tify this situation by trying to press that button and checking if the corresponding LED is glow-

ing or not. Of course you have to connect the joystick to the adapter and switch on the mains

power before you try. If the LED does not glow then we can be quite sure that the button has

gone bad and needs to be replaced. This is with consideration that other things in the circuit are

okay.

The motor is making noise which tells me that the motor is working, but the motor shaft

is not rotating at all or it rotates intermittently! Why?

The motor has a gear box in front of it which is white or black in colour. The rotations that is

produced by the motor are transmitted to the wheels by means of a gear box which is connected

to a shaft. Sometimes, due to unbalanced or large load, the gearbox or the gears itself may break

and the motor loses contact with the shaft. This causes the motor to rotate freely while the shaft

stays stationary. If this is the case, then there is no other option than to get the motor replaced.

I am tightening the nut on the motor, but the nut does not stop after tightening! Why?

If you have over tightened the not on the motor, chances are that the gear box has broken off

from the threading. If this is the case, you have to get the motor replaced.

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Everything is working on the joystick, but still the robot is not moving! Why? There may be numerous reasons for this to happen. Below we will try to list some of the com-

mon errors or problems

1. The wires may have come out of the square PCB inside the metal box. Open the box and

check!

2. Check the motors! The gear box of the motors may have broken.

I want the robot to work using a battery. Can I do that? Yes you can! Have you noticed the battery connector labelled 12V DC on the square PCB which

goes inside the machine? If you want to use a battery instead of the adapter, you will have to buy

a battery pack from us and connect it to the battery connector on the square PCB. If you do that,

you will not require to connect the adapter to the joystick. And when the battery runs out, you

can connect the adapter to the joystick and switch on the power which will charge the battery

simultaneously.

I want to make the robot wire-free! Can I do that?

Yes you can! Right now there are two wires that keep you limited within a specific radius from

the wall electrical outlet. First of all, if you want to move away from the wall outlet, you will have

to buy a battery pack from us and install it. You are now limited to two meters distance from the

machine due to the FRC cable. If you want to make the machine completely wireless, you will

have to buy a wireless kit from us and install it in your robot. All the kits and accessories are

available to be reviewed and ordered at our website http:/ /www.robosoftsystems.co.in/

roboshop

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Appendix A

Improving Machine Performance

2. Lifting Heavy Load

If you want to modify your machine in such a way that your machine can lift more weight

then , you have to go through a few basics concept of physics.

Torque: Since you want to lift heavier weight you will require higher power. So basically

you have to use a motor with higher torque for lifting it.

Center of gravity: Even if you attach a higher torque motor, you may not be able to lift a

heavier load. This is because you have to take another concept into consideration: center of

gravity.. The center of gravity (also called the center of mass) of a system of particles is a

specific point at which, for many purposes, the system's mass behaves as if it were concentrated.

1. Make machine faster

Currently your robot is driven with two 45 RPM motors. Generally if you change the

(Revolution Per Minute) of your motors the speed of your robot is also changed. Higher the

RPM, more the speed and lower the RPM, lesser the speed.

With your kit you are getting two 45 RPM motors, you can change those motors with60RPM or 100RPM Motors. Logon to ROBOSHOP on http:/ / www.robosoftsystems.co.in/

roboshop/ for details.

Similarly you can modify lifting mechanism by changing the motor used for gear box.

Using a higher RPM motor will make your lifting movement fast.

But RPM is not the only parameter concerned with motor performance. The other

important parameter is Torque. Greater the torque, more power is delivered on motor shaft

output. So if you want to lift heavy load you can switch to high torque motors.

Generally RPM and Torque of a motors depends upon the gear ratio used inside the

gearbox for DC motors. Higher gear ratio will cause lesser RPM but higher torque ,similarly low

gear ratio will result in to higher RPM but lesser torque. So its advisable to select motor wisely

for your robot.

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The center of mass of a body does not always

coincide with its intuitive geometric center, and one can

exploit this freedom. Engineers try to design a sports

car's center of mass as low as possible to make the car

handle better. When high jumpers perform a "Fosbury

Flop", they bend their body in such a way that it is pos-

sible for the jumper to clear the bar while his or her

center of mass does not.

.Center of gravity

As explained before, the center of gravity of a body can be shifted. In the diagram

above, note that increasing the height of the vehicle by placing a load moves it up.

By placing the machine on an inclined plane, the center of gravity moves outside

the body of the machine.

http://en.wikipedia.org/wiki/Fosbury_Flop





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The machine is now free, i.e. it is carryingno load at all. So the center of gravity of the

machine will be at the point where it was actually

designed.

At this point of time, the machine is trying

to lift a load which is manageable for the machine.

Notice how the center of gravity of the machine

has moved from the previous point.

The machine now tries to lift a heavier

load. This load cannot be managed by the machine

so now it will topple over. This is because the

center of gravity has shifted far away to the

extreme corner of the machine. This unbalance of

load cannot be handled by the machine and it top-

ples over.

Mg

N1 N2X

Mg

N1 N2X

Mg

N X

To prevent the machine from toppling

over, we can either reduce the load to be lifted. I f

the load has to remain the same, then we can add a

counterweight at the back of the machine so that

the center of gravity can come back to its designed

position once again. But this increases the overall

weight of the machine thereby increasing the load

on the machine.

Mg

N1 N2X

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Locomotion

Robot locomotion is the study of how to design robot appendages and control

mechanisms to allow robots to move fluidly and efficiently. Although wheeled robots are

typically quite energy efficient and simple to control, other forms of locomotion may be more

appropriate for a number of reasons (e.g. traversing

rough terrain, moving and interacting in human

environments).

Different Types of Locomotion‘s Are

Wheeled Locomotion

Legged Locomotion

Flying Locomotion

Floating Locomotion

And many more

Let us now come to the most common form of locomotion that you can see in your day

– to – day life. This kind of motion is the most primitive one and the most simple to understand.

It is said the most important invention that mankind has made after he discovered fire, was the

invention ofwheels.

You can find wheels attached to nearly all kind of vehicles that you can find. How do you

expect to move a heavy weight from one place to another? Simple! Just attach wheels to it!! Justthink how the Egyptians had carried so big stones to build their pyramids? If you get the answer

to this one, you would understand the importance. What is a wheel? It is essentially a circle. What

is the circumference of a circle? The value will be2πr. Now what does circumference imply? If

you rotate a circle by 360o, then the amount of distance covered will be2πr, wherer is the radius

of the circle.

Appendix B

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Thus, the bigger a wheel is, the more distance it will cover in one rotation. I am sure that

you have now understood why a bus has bigger tires than a car.

Now the question is what one should look for while selecting the wheels:

1. Keep ground clearance in mind while selecting the wheels.

2. The wheels should not be to smooth as they will skid while accelerating and braking.

3. They should not be rough as they will lead to higher friction.

4. If the width of the wheels is wider then more is the resistance for wheels to turn.

Why to have Belt/ Track Mechanism ?

Disadvantage of wheeled transmission system is off road mobility failure. It is because of

very small ground contact which applies high pressure on ground and it causes your machine or

robot to loose its stability if density of soil is low ( i.e. muddy surface). To over come this prob-

lem we can use belt or track mechanism.

Drives

Now we will look into several types of common drive mechanisms.

1. Two wheel drive

Easy to design

Easy to build

Light weight

Inexpensive

Not much power

Will not do well on ramps

Less able to hold position

Motor Motor

DriveWheel

Caster

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2. Four wheel drive, two motors

Easy to design

Easy to build

Inexpensive

Powerful

Sturdy and stable

Not agile

Turning is difficultAdjustments are needed

Motor Motor

Drivewheel

Chain/belt

Drivenwheel

3. Four wheel drive, four motors

Easy to design

Easy to build

Powerful

Sturdy and stable

Many options

Heavy

Costly

Motor Motor

Drivewheel

Motor Motor

4. Four wheel drive, two motors

Easy to design

Easy to buildPowerful

Stable

Heavy

Expensive

Motor Motor

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5. Belt drive, two motors

Powerful

VERY stable

NOT AGILE

Heavy

Costly

Inefficient

Hard to maintain

Motor Motor

6. Three wheel drive

Various types

Lightweight

Fast

Non — standard

Motor Motor

Mobility

Move ± 1 foor in any direction in under 1 second

Generally speaking, the more mobile your robot is, the less it can resist a push.

More mobile Less mobile

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C

Only small area in ground contact =

high ground pressure

Large surface area in ground contact =

Low ground pressure

Excellent off road mobilityOff road mobility failure

Footprint

Advantage of using Track/ belt systems in our Robot

1. Excellent off road stability

2. Two motors to control four wheels, so user don't have to concern about co-ordination of

each side motors. Since the motors used are less in number power consumed will be also

less hence less power consumption in case of our robot.

C

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Switch and Navigation

In electronics, aswitch is an electrical component which can break an electrical circuit,

interrupting the current or diverting it from one conductor to another. The most familiar form

of switch is a manually operated electromechanical device with one or more sets of electrical

contacts. Each set of contacts can be in one of two states: either 'closed' meaning the contacts

are touching and electricity can flow between them, or

'open', meaning the contacts are separated and

non-conducting.

Types of switches

SPST – Single Pole Single Throw.

SPDT- Single Pole Double Throw.DPST- Double Pole Single Throw.

DPDT- Double Pole Double Throw.

The terms pole and throw are also used to describe switch contact variations. A pole is a

set of contacts, the switch's electrical terminals that are connected to and belong to a single

circuit, usually a load.

On our joystick we will be using SPDT switches, so first let‘s see how SPDT works Inthis type of switch we can operate two devices. It is a simple changeover switch. The SPDT

switch has two terminals, one of the terminals is common and the other connects either light A

to the supply when in one position or connects light B to the supply when in other position.

Appendix C

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Switch Position A Switch Position B

Battery

Light A

Light BSwitch

Position A

SPDT

Battery

Light A

Light BSwitchPosition B

SPDT

SPDT switches which we are using are push button kind of thing. Connections are done

exactly in opposite manner. In this case common terminal is output pin and selective terminals

are input. In our case we are having two inputs as 0volt and 12 volt and output voltage is

determine with switch position. When switch is pressed output will be equal to 12 volt and it is

equal to 0 volt when released.

KEY Released

12 V0 V 0 V

KEY Pressed

12 V0 V 12 V

Output

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On our Remote control there are 8 SPDT switches are provided .You can use any pair

of switches to control a single motor. When the motor is subjected to the voltage of different

polarity it will change its rotational direction. The figure and table below will illustrate how your

motor will be controlled.

MSPDT Switch 1 SPDT Switch 2

0 Volt

12 Volt

0 Volt

12 Volt

Switch 1 Status Voltage Motor Status Voltage Switch 2 Status

Released 0 Free Stop 0 Released

Released 0 Clock wise 12 Pressed

Pressed 12 Anti-clock wise 0 Released

Pressed 12 Break Stop 12 Pressed

Since you have got 8 keys available on your remote control you can connect 4 motors

and control them with a set of 2 key.

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How to navigate your robot controlling motors mounted on robot. The design used todrive your robot is known as Differential Drive .The differential drive design has two individual

motors or two sets of motors mounted in fixed position on the left and right side of robot,

independently driving wheels on each side.

Differential drive design is mechanically simple in construction because it does not

require rotation of driving axis (i.e. staring mechanism).

But controlling differential drive systems is more complex because of coordination of

wheels on both side. Your both wheels should move in same speed else your machine will

deviate from the path and never go straight. Now figure below will explain driving direction of

machine when both side motors run at same speed.

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Appendix DGear box

Gears:

Gears are one way to transfer motion from one place to another. They work together in

groups of two or more. One gear turns another, which may turn another, and so on...

Gears are measured by counting the number of teeth they have. When used with an axle,

gears are an example of the simple machine called the "wheel and axle". Gears can combinetogether in many different ways to transfer motion. Gears can increase or decrease force, torque

or speed or change direction.

Application of Gears:

• Change the plane of rotation. • Increase or decrease the speed of Applied Motion. • Magnify or reduce the Applied Force. • Provide a drive without slippage.

Driver

Follower

Driver: A driver is a gear that you or a motor turns.

Follower: The gear turned by the driver is called the follower

The driver is the boss telling the follower how to turn.

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Gear Calculations:

On any gear, the ratio is determined by the distances from the center of the gear to the

point of contact. For instance, in a device with two gears, if one gear is twice the diameter of the

other, the ratio would be 2:1. Gears are measured by counting the number of teeth‘s they have.

Now if we have understood the different terminologies of gear then lets try and check or

understanding.

Let‘s say that we have two gears in combination, and then the product of speed and teeth

is conserved.

Let's put this in terms of usable math. Let's say that we have two gears in mesh. Gear 1

(we'll call it the driver) is turning at speed S1 rpm and has T1 teeth. Gear 2 (the driven gear) is

turning at speed S2 and has T2 teeth. Then our relationship above says that:

S1* T1= S2 * T2

Suppose you have a driver gear with 60 teeth‘s and a follower gear with 20 teeth‘s calculatethe gear ratio.

Solution:

Gear Ratio = [number of teeth‘s on the follower] / [number of teeth‘s on the driver]

Gear ratio = 20/60.

Therefore,

Gear ratio= 1:3

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Spur Gear

Worm Gear

Spur gears are the most common type of gears.

They have straight teeth, and are mounted on

parallel shafts. Sometimes, many spur gears are

used at once to create very large gear reductions.

The gear reduction produced is a function of the

diameters of the two gears after gear reduction, the

torque and R.P.M attained by the system usually

follow an inverse relationship. The problem with spur gear is that they are very

loud. The reason for this being that due to

inefficiencies in design, there is always some impact

taking place when two teeth are coming in contact. Each time a gear tooth engages a tooth on the

other gear, the teeth collide, and this impact makes a noise. It also increases the stress on the gear

teeth.

Worm gears are used when large gear reductions

are needed. It is common for worm gears to have

reductions of 20:1, and even up to 300:1 or

greater.

Many worm gears have an interesting property

that no other gear set has: the worm can easily

turn the gear, but the gear cannot turn the worm.

This is because the angle on the worm is so

shallow that when the gear tries to spin it, the

friction between the gear and the worm holds the worm in place. A gearbox designed using a

worm and worm-wheel will be considerably smaller than one made from plain spur gears and has

its drive axes at 90° to each other. With a single start worm, for each 360° turn of the worm, the

worm-gear advances only one tooth of the gear.

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Therefore, regardless of the worm's size (sensible engineering limits notwithstanding), the

gear ratio is the "size of the worm gear - to - 1". Given a single start worm, a 20 tooth worm gear

will reduce the speed by the ratio of 20:1. With spur gears, a gear of 12 teeth (the smallest size

permissible, if designed to good engineering practices) would have to be matched with a 240

tooth gear to achieve the same ratio of 20:1. Therefore, if the diametrical pitch (DP) of each gear

was the same, then, in terms of the physical size of the 240 tooth gear to that of the 20 tooth gear,

the worm arrangement is considerably smaller in volume.

Unlike with ordinary gear trains, the

direction of transmission (input shaft

vs output shaft) is not reversible, due

to the greater friction involved

between the worm and worm-wheel,

when a single start (one spiral) worm

is used. This can be an advantage

when it is desired to eliminate any

possibility of the output driving the

input. If a multistart worm (multiple

spirals) then the ratio reduces

accordingly and the braking effect of

a worm and worm-gear may need to be discounted as the gear may be able to drive the worm.

Worm gear configurations in which the gear can not drive the worm are said to be self-locking.

Whether a worm and gear will be self-locking depends on the lead angle, the pressure angle, and

the coefficient of friction; however, it is approximately correct to say that a worm and gear will

be self-locking if the tangent of the lead angle is less than the coefficient of friction

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Appendix EOptional Accessories

BATTERY PACK

Want to increase the range limitation of your robot? Use the battery!

Features

1. Rechargeable nickel cadmium cells

2. 12V DC , 600mAH supply

3. Ample power to drive the machine for long durations once charged fully.

4. Available in standard packaging.

5. 10 cells inside the packaging.

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The above diagram shows how to connect the battery pack to your machine. We assume that

you are done with the other parts. You must have noticed that the battery has two wires; red

and black. The red wire is positive and the black wire is negative. We have discussed about the

battery connector in the square PCB before, remember? You will have to connect the red wire

of the battery to the ‗+‘ marked terminal of the battery connector and the black wire of the

battery to the ‗-‘ marked terminal of the battery connector. Of course you do not need to

connect the adapter to the joystick if you want to use the battery. If you run out of battery

power, you have to simply plug in the adapter to the joystick and power on. The machine sup-

ports on-board charging. So you can use your robot even while charging your machine!

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A-61, 1 st Floor, Raj Industrial Complex,Military Road, Marol,

Andheri (East),

Mumbai –

400059India

Contact InformationOffice: (91-22) 66751507Office: (91-22) 29207086Mobile: (91) 9930776661

Email: [email protected]

Visit us atwww.robosoftsystems.co.in

mailto:[email protected]



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