The document provides information on the steps for installing machine tools and the advantages of acceptance testing. It discusses 5 steps for installation: 1) initial inspection, 2) removing rust prevention coating, 3) foundation preparation, 4) placing the machine tool, and 5) test run. Acceptance testing guides proper setup, helps preventive maintenance, and determines machine condition and useful life. The document also defines numerical control of machine tools and lists advantages of programmable NC machines.

1. 1
Dr. M. Kamruzzaman
Assistant Professor, Dept. of ME, DUET, Bangladesh
Class note on ME-433
Steps of Installation of Machine Tools
1. Initial Inspection
(a). Open the packing immediately.
(b).Check or any transport damage and shortage.
(c). Check according to packing list enclosed.
(d).Incase of complaint, it should convey immediately to the local dealer quoting
the type of machine tool and serial number.
(e). Send the complain copy to the head office, servicing centre etc.
2. Remove the rust pretension coating
(a). Remove the rust pretension coating from the bright and sliding parts by
kerosene, use soft cotton waste to wash away the preventive coating and wipe
with dry cloth. Don’t use any solvent that dissolve paint.
(b). Give oil to all bright parts by oil gun.
(c). Clean the oil nipples.
(d). Unclamp moving parts which are generally clamped with fixed parts i.e saddle
of lathe clamped with guide ways.
3. Foundation
(a). Preparation of foundation
(b). Provide sufficient space for operator, machined work-piece and material to be
machined.
(c). Cure the concrete made foundation before placing the machine on it.
4. Placing of machine tool
(a). Sling the machine by hemp rope, felt padding (some times chain/ rope) with the
help of crane.
(b). Foundation bolts; leveling plates are introduced from below, place leveling
screw at the seat in the blind holes given in each plate.
(c). Level with the help of leveling screw and spirit level with a sensitivity of 0.03
to 0.06 mm/meter.
(d). Cement grouting to foundation bolts and allow some time for hardening.
(e). Check level again near head stock, tail stock and middle position.
5. Test run
(a). Run the machine tool for about two hours at various speed.
(b). Ensure the correct level.
(c). If any level correction is done, run the machine for one hour at medium speed.
(d). Apply grouting to machine level screws.
Advantage of Acceptance Test
Test of machine tool has the following advantages:
1. Testing guide the metal properly
2. It helps in preventive maintenance of machine tool
3. It helps to determine the condition of machine tool and hence it’s useful life

2. 2
* Classification of Test:
Machine tool testing can be classified as:
1. Geometrical test or alignment test
2. Performance test or practical test
1. Geometrical Test: It conveys the manufactured error of the machine tool. They
checked on the relationship of various elements of machine tools in idle and unloaded
condition.
2. Performance Test: It is used to check working accuracy of machine the tool. Both
geometrical and performance test are collectively known as acceptance test.
* Effect of Vibration on Machine Tools:
The effect of vibration on machine tools can be considered on four points:
(1) Effect of vibration on machine tool itself: The machine tools are made of various
parts. When vibration is produced, the various parts also start vibrating at same
frequency of the vibration source.
(2) Effect of vibration on work piece: vibration if present, the surface finish and
dimensional accuracy of the job are affected.
(3) Effect of vibration on cutting condition: Due to vibration the cutting velocity
don’t remain constant, chip thickness change and cutting force will also be
changed.
(4) Effect of vibration on tool life: Due to vibration the life of cutting tools is reduced
lay 70 to 80% of their normal value.
* Sources of Vibration:
The sources are given below
(1) Non homogeneous work piece material
(2) Built up edge on cutting tools.
(3) Disturbance in the drives and unbalanced drives.
(4) Intermittent cutting
(5) Transmission of vibration from the ground which vibrate due to other reasons.
(6) Generation of vibration from cutting processes.
* Types of Vibration:
In metal Cutting two types of vibration may takes place
(1) Forced vibration
(2) Self vibration
(1) Forced Vibration: The seasons responsible for forced vibration are:
(a). Vibration made for Cutting force
(b).Centrifugal force of inertia of unbalanced mass
(c). For transmitting motion
(d).For rough spindle bearing
Force vibration results in increasing amplitude of vibration which is called
regenerative chatter.

3. 3
* What do you mean by automatic transfer line? Classify them and describe different
component of an automatic transfer line.
An automatic transfer line is a system of machine tools work transference devices and
checking devices which automatically carry out machining or assembly with
predetermined interconnection and sequence being operated by a central control system.
Automatic transfer lines fall into the following categories:
1. Depending on the made of feeding blank into the line and ejecting finish parts out of
the line
(a). piece by piece
(b).A group of parts.
(c). A continuous flow of parts
2. Depending on the rate of production:
(a). Single flow
(b).Multiple flow
3. Depending on the types of machine tools employed:
(a). Transfer lines with special machine tools
(b).With unit built machine
(c). With semi and full automatic general purpose machine
(d).With automatic universal machine
4. Depending on the types of inter machine transfer system:
(a). The pass through type
(b).The overhead type
(c). The side loading type
(d).The combined transfer type
(e). The rotary conveying type
5. Depending on the arrangement of equipment:
(a). Closed loop type
1. Circular
2. Rectangular
(b). open loop type
1. Straight line
2. L-shape
3. U-shape
4. W- shape
5. Zig Zag
6. Depending on the kind of work piece machined:
a. Housing type parts
b. For shaft
c. For due shaped parts
d. For anti friction bearing race
e. For small parts (screw, pin, roller etc)

4. 4
* Equipments of Transfer Lines
(a). Conveying devices (conveyor, chutes, tubes, mechanical hands)
(b).work piece locating and clamping device
(c). storage unit
(d).chip disposal system
(e). transfer line control system
1. Conveying Device:
(a). conveyor
(b).mechanical hands
(c). chutes
(d).tubes
are used to transfer the parts being machined from one to the next machining station in
transfer line.
Other types of conveyor as used as well as intermittent conveyors
(a). Transfer bar of the disappearing finger type
(b).Transfer bar of the rotating finger type
(c). Transfer bar of the walking beam type
(d).Overhead transfer bar with grips
(e). Chain conveyor
(f). Intermittent conveyor with pushing type
(a) Transfer Bar disappearing Finger Type
Conveyor
(b) Transfer Bar Rotating Finger Type Conveyor
(c) Transfer Bar of the Walking Beam Type
Conveyor
(d) Overhead Transfer Bar with Grips Conveyor
(e) Chain Conveyor (f) Pushing Type Intermittent Conveyor

5. 5
A transfer bar of rotating finger type provides higher accuracy of work piece
movement and positioning on machining stations. Transfer bar 3 with fingers I is imparted
a periodic reciprocating motion and a rotating motion about the bar axis. The work piece
being machined is moved only during the forward stroke of the bar.
A transfer bar of the walking beam type is shown schematically. To convey the work
pieces, bar 3 are imparted two consecutive reciprocating motions in the horizontal and
vertical planes. Work pieces 2 are driven by fingers 1.
An overhead transfer bar with grips is a complicated version of the walking beam
type, in which work pieces 2 are transferred by means of grips 1. The grips are carried by
bar 3, which move above the work pieces.
An intermittent conveyor of pushing type transfers work pieces 2 by means of piston
rod 3 of a hydraulic or pneumatic cylinder. During the forward stroke, the piston rod
pushes simultaneously all the work pieces or pallets (i.e. holding fixtures) located on the
conveyor.
Chain conveyors are used in many transfer lines where continuous motion of the work
pieces being machined is required. This type of conveyor is hardly ever used for
intermittent motion, because it cannot provide accurate work transference for location and
clamping at the machining stations.
2. Work piece locating and clamping devices:
(a). Stationary fixture
(b).Individual traveling fixture
Function of work piece above the fixture
(1) Tentative orientation of work piece
(2) It’s final location, clamping and release
(3) Guidance of cutting tool during machining
3. Storage unit:
(1) The progress through type
(2) Blind alloy type
4. The chip disposal method in transfer line:
(a). Mechanical method
(b).Gravity method
(c). Removed by means of liquid or compressed air jet
(d).By means of electromagnets
5. Transfer line control system:
To ensure the sequential action of component machine tools and mechanisms built
into automatic transfer line.

6. 6
*Define N C machine? What are the advantages of N C control?
As a machine tool is said to be numerically controlled if it operates in a semi-automatic or
automatic cycle as per instruction transmitted to it in a coded form.
* Advantages of N C
The advantages of programmable machine tools can be summarized as follows:
(1) Flexibility
(2) High production rate
(3) Superior process capability
(4) Lower tooling costs
(5) Lower lead time
(6) Less scrap
(7) Less skill required of the operator
(8) Reduction inventory
(9) Reduction in space required
(10)Better machine utilization
(11)Unique geometrics manufacture
* Describe elements of N C system and write their principle with the example of
turning. or describe open loop system N C machining.
Open loop: If the operative member of the machine tool is directed to move to a
certain position then the system is called open loop system. In other words, there is no
feed back on the accuracy of execution of the path magnitude commands.
Elements of open loop
1. Programme medium
2. Programme reader
3. Buffer storage
4. Decoder
5. Amplifier
6. Drive

7. 7
1. Programme medium: The information coded on a programme medium. Such as a
punch card, punch tape, magnetic tape etc. In this code as many holes are punched
on the paper tape as the number of impulses required.
2. Programme reader: The punched tape is passed through a programme reader,
which identifies the presence or absence of a hole and sends the corresponding
information to the decoder.
3. Decoder: The decoder generates a pulse every time a hole is sensed.
4. Amplifier: The decoder electrical signal is amplified and fed to a stepping motor.
5. Stepping motor is coupled to the led screw of the lathe.
6. Drive: The input of an impulses to the stepping motor results of it’s rotor through a
particular angle which converted through the screw and nut mechanism into
translatory displacement of the tool post.
*Draw the block diagram of a close loop NC machine and mention function of each
of its elements?
If the operating member of the machine tool is precisely arrive at the desired position or
not, is not ascertained. In other word N C systems with a feedback device are known as
close loop system.