Haloading276

1. Lathe Controls The Mechanical
2. Lathe Mechanic

After reading this article you will learn about:- 1. Meaning of Cutting Tool 2. Types of Cutting Tools 3. Angles 4. Signature.

A male operator controls the CNC machine while standing at the control panel. Technology instrument machine industry service operator monitor panel work tool indoors production manufacturing engineering workshop mechanic worker control maintenance engineer manufacture factory automated automatic technician lathe processing. Application of Lathe Machine. The lathe machine is used in metal working, wood turning, metal spinning, parts reclamation, thermal spraying, and glass working. It can be used to shape pottery, the potter’s wheel is the latest well-known design made by a lathe. Many people know Lathe machine and saw in there laboratory or company but not aware much about parts of lathe machine and lathe machine diagram. So here we will explain what it is, how to use and their parts. Provides lathe repair services. Heavy-duty horizontal and vertical CNC turning lathes can be serviced. Capabilities include rebuilding, retooling, retrofitting, cleaning, disassembling, assessment, reassembling and testing. Machine tool, material handling, railroad, fixturing and tooling industries served.

Meaning of Cutting Tool:

A cutting tool in metal working can be defined as “any tool that is used to remove metal from the work piece by means of shear deformation”. Frequently, it also refers as a tool bit. In order to perform effective cutting operation, the cutting tool must be made of a material harder than the work material to be cut. Also, the tool must be able to withstand the heat generated during machining process.

The tool must have a specific geometry (known as tool geometry) for effective cutting and smooth surface finish. According to the tool geometry, the cutting tools can be classified into solid cutting tools and carbide tipped tools.

ADVERTISEMENTS:

There are two surfaces adjacent to the cutting edge of the tool:

(a) Rake surface.

(b) Flank surface.

(a) Rake Surface:

Rake surface directs the flow of newly formed chip. It is oriented at a certain angle is called the rake angel ‘a’. It is measured relative to the plane perpendicular to the work surface. The rake angle can be positive or negative.

(b) Flank Surface:

The flank surface of the tool provides a clearance between the tool and the newly formed work surface, thus protecting the surface from abrasion which would degrade the finish. This angle between work surface and the flank surface is called the relief or clearance angle.

Types of Cutting Tools:

Various cutting operations require various types of cutting tools. To achieve good surface quality, proper cutting tool selection is very important.

ADVERTISEMENTS:

Following are some important parameters to be considered while selecting a cutting tool for particular machining operation:

i. Geometry.

ii. Material to be machined.

iii. Shape and Size of part.

iv. Type of operation required.

v. Machine tool quality.

vi. Surface finish required.

vii. Holding facility.

ADVERTISEMENTS:

viii. Machining parameters such as feed speed and depth of cut selected.

The various types of cutting tools are shown in Fig. 9.11.

The major classifications of cutting tools are following:

(i) According to Construction:

(a) Solid tool.

(b) Carbide tipped tool.

(ii) According to Number of Cutting Edges:

(a) Single point tool.

ADVERTISEMENTS:

(b) Multipoint tool.

(c) Formed (Tailor designed) tool.

(iii) According to Shape:

(a) Square.

(b) Circular.

(c) Left hand.

(d) Right hand.

(e) Round nose.

(f) Straight nose.

(iv) According to Operations:

(a) Turning.

(b) Drilling.

ADVERTISEMENTS:

(c) Threading.

(d) Knurling.

(e) Boring.

(f) Forming.

(g) Parting-off.

(h) Reaming.

(v) According to Type of Cutting Tool Material:

(a) H.S.S.

(b) Carbide.

(c) Ceramics.

(d) Diamond.

Cutting Tool Angles:

The face and the flank are pain surfaces, the cutting edge can be assumed to be a line. These surfaces and the edges are inclined with respect to some reference plan or line. The inclinations are called tool angles.

These angles are defined by various names. They are provided for various purposes. Consider the case of the face abgf, as shown in Fig. 9.12. It is a plane surface no doubt, but can have some inclinations. This surface may be parallel to the base or say to horizontal surface, or it can be inclined upward or downward with respect to the horizontal plane. Again it may have inclination sideward also. So in general the face can have two inclinations simultaneously, backward and sideward. Similarly the flank (Principal flank abed or auxiliary flank adef) can have two inclinations.

For efficient machining operation, the cutting tool must be provided with necessary tool angles. A tool with proper geometry (cutting edge and tool angles) cuts the metal effectively. Therefore reducing the chattering, breaking of the tool with less heat generation. Fig 9. 14. (a) and (b) shows a single point cutting tool with various cutting edges and tool angles.

From the geometry of cutting tool the various cutting tool angles are:

Rake Angle (α):

(a) Black rake angle.

(b) Side rake angle.

Clearance or Relief Angle (γ):

(a) End clearance relief angle.

(b) Side clearance relief angle.

Cutting Edge Angle:

(a) End cutting edge angle.

(b) Side cutting edge angle.

(i) Back Rake Angle:

It is the angle between the face of the tool and plane parallel to its base. It is also known as front rake angle or top rake angle.

(ii) Side Rake Angle:

It is the angle between the face of the tool and the shank of the tool.

(iii) End Clearance (Relief) Angle:

It is the angle between the front surface of the tool and a line normal to the base of the tool. It is also known as front clearance angle.

(iv) Side Clearance (Relief) Angle:

It is the angle between the side surface of the tool and a line normal to the base of the tool.

(v) End Cutting Edge Angle:

It is the angle between the end cutting edge of the tool and a line perpendicular to its shank.

(vi) Side Cutting Edge Angle:

It is the angle between the side cutting edge of the tool and shank of the tool.

(vii) Nose Radius:

Nose radius is one which connects the side and end cutting edge. Now, we will discuss the functions and effects of cutting tool angles on cutting process.

Functions of Back Rake Angle:

(a) It helps to control the chip flow in a convenient direction.

(b) It reduces the cutting force required to shear the metal and consequently helps to reduces power requirements and increase tool life.

(c) It also helps counteract the pressure against the cutting tool from the work by pulling the tool into the work.

(d) It provides keenness to the cutting edge and improves the surface finish.

Functions of Side Rake angle:

(a) It performs similar functions as performed by back rake angle.

(b) Side rake angle along with back rake angle controls the chip flow direction.

(c) It partly counteracts the resistance of the work to the movement of the cutter.

(d) For example, brass requires a back and side rake angle of almost 0°, while aluminum uses a back rake of 35° and a side rake of 15°.

Functions of End Clearance (relief) Angle:

(a) It allows the tool to cut freely without rubbing against the work surface.

(b) This angle varies from 0° to 15°, and usually 8°.

(c) Excessive relief angle reduces strength of the tool.

Functions of Side Clearance (relief) Angle:

i. It avoids the rubbing of flank against the work piece when the tool is fed longitudinally.

ii. This angle is 6° to 10° for steel, 8° for aluminum.

iii. It maintains that no part of the tool besides the actual cutting edge can touch the work.

Functions of End Cutting Edge Angle:

i. It avoids rubbing between the edge of the tool and workspace.

ii. It influences the direction of chip flow.

Functions of Side Cutting Edge Angle:

i. Increase in side cutting edge angle tends to widen and thin the chip.

ii. An excessive side cutting edge angle redirects feed forces in radial direction which may cause chatter.

Functions of Nose Radius:

i. A sharp point at the end of tool is undesirable, because it is highly stressed, short lived and leaves groove in the path of cut.

Lathe Controls The Mechanical

ii. Therefore Nose Radius is favourable for long tool life and good surface quality.

iii. It affects the tool life, radial force, and surface quality of work piece.

iv. If nose radius is too large chatter will occur.

v. There is an optimum value of the nose radius at which the tool life is maximum.

vi. If the nose radius exceeds optimum value, the tool life decreases.

vii. Larger nose radius means larger area of contact between tool and work piece. Resulting more frictional heat is generated. Also, cutting force increases due to which the work part may start vibrating and chattering, if work part holding is not very tight.

viii. The recommendations for use of more nose radius are.

R= 0.4 mm for delicate components.

R = 0.4 mm to 1.2 mm for disposable carbide inserts for common use.

R = 1.2 mm to 1.5 mm for heavy duty inserts.

R ≥ 1.5 mm for heavy depth of cut, interrupted cuts and heavy feeds.

Significance of Rake Angle:

1. The rake angles may be positive, zero or negative.

2. An increased rake angle will reduce the strength of the cutting edge.

3. Rake angle affects the values of cutting angle and the shear angle.

4. Larger the rake angle, smaller the cutting angle (and larger the shear angle).

5. In general, the small rake angle is used for cutting hard metals and a larger rake angle is used for cutting soft and ductile metals.

6. The use of negative rake angle started with the employment of carbide cutting tools. When positive rake angle is used, the force on the tool is directed towards the cutting edge, tending to chip or break it, as shown in Fig. 9.15(a).

7. Since the carbide material is brittle and lacks shock resistance, it will fail if positive rake angles are used with it. Using negative rake angles, directs the force back into the body of the tool away from the cutting edge, which protects to the cutting edge, as shown in Fig. 9.15 (b).

8. The use of negative rake angle increases the cutting force. This can compensate by higher cutting speeds. Therefore, high cutting speeds are always used with negative rake angles. High cutting speeds require high power of the machine tool.

9. The use of index able inserts also need the use of negative rake angles.

10. A negative rake angle insert has twice life than an equivalent positive rake angle insert.

11. Negative rake angle increases cutting edge strength, because the cutting force acts on the middle of cutting edge.

12. Positive rake angle decreases cutting edge strength, because the cutting force acts on the end or corner of the cutting edge.

13. Positive rake angle recommendations are:

(a) When machining low strength metals and alloys, such as aluminum and copper alloys, mild steel, etc.

(b) Where cutting at low speeds.

(c) When set up has low strength and rigidity.

(d) When low power machines used.

(e) When tool materials are H.S.S. and cast alloys.

14. Negative rake angle recommendations are:

(a) When machining high strength metal and alloys, such as stainless steel, alloy tool steel, titanium alloys, etc.

Table 9.4. Gives the recommended rake angles for various combinations of work and tool materials:

Tool Signature:

Tool signature is the specification or nomenclature of the tool which provides information regarding various tool angles and nose radius.

It includes seven parameters in specified order as given below:

(i) Back rake angle.

(ii) Side rake angle.

(iii) End relief (clearance) angle.

(iv) Side relief angle,

(v) End cutting edge angle.

(vi) Side cutting edge angle.

(vii) Nose radius.

For example:

(a) If the tool signature is 12, 15, 7, 6, 10, 15, 0.8

Means,

Back rake angle (degree): 12

Side rake angle: 15

End relief angle: 07

Side relief angle: 06

End cutting edge angle: 10

Side cutting edge angle: 15

Nose radius (mm): 0.8

(b) If the tool signature is -10, 15, 8, 6, 8, 5, 0.5

Here, also the meaning is back rake angle is negative 10 degree, side rake angle is 15 degree, End relief angle is 08 degree, side relief angle is 06 degree, End cutting edge angle is 08 degree, side cutting edge angle is 05 degree and nose radius is 0.5 mm.

Precision and high repeat accuracy for individual parts and small series manufacture. Made in Germany.

Lathe Mechanic

• Z-axis and X-axis with recirculating ball spindles and two powerful step motors.
• Control unit for connecting to PC or laptop with activation of the main spindle and the step motors.
• Including user-friendly and WINDOWS® compatible software (see description below).

High quality RÖHM precision 3-jaw lathe chuck. Witt Ø 100mm.
Powerful condenser motor with 550W.
Multiple steel holder with height-adjustable holder elements.
Step motor 1.8A for travel distance 70mm.
Recirculating ball spindle for the X-axis with 2.0mm inclination.
Recirculating ball spindle for the Z-axis with 4mm inclination.
Step motor 1.8A for travel distance 300mm.

CNC control of Z-axis and X-axis enables precise turning, facing and longitudinal turning of steel and non-ferrous metal.
Axes drive with powerful step motors and recirculating ball spindles (no backlash). For facing and longitudinal turning, for turning balls, radii and any freely formed contours made of steel and non-ferrous metal. Work piece machining is effected automatically by software and can be reproduced as often as required.
Otherwise the mechanical design is almost identical to the proven PROXXON lathe PD 400: Solid, cross-braced cast iron bed with ground and wide legged prism guide for apron and tailstock ensure vibration-free working and optimum precision. High quality 3-jaw lathe chuck (Ø 100mm). 6 spindle speeds (80 - 2,800/min) are provided via belt drive. Including rotating centre MK 2 and tailstock chuck. With quick-change tool post with 2 holders (with stop and height adjustability).
Complete with recirculating ball spindles, powerful step motors and the required limit switches, the CNC control unit, all necessary connecting cables and WINDOWS® compatible software on CD-ROM.
NO 24 500

1. Precision 3-jaw lathe chuck as per DIN 6386 (Ø 100mm).
2. Powerful condenser motor with 550W.
3. Multiple steel holder with height-adjustable holder elements.
4. Step motor 1.8A for travel distance 70mm.
5. Recirculating ball spindle for the X-axis with 2.0mm inclination.
6. Recirculating ball spindle for the Z-axis with 4mm inclination.
7. Step motor 1.8A for travel distance 300mm.

Double roller bearing recirculating ball spindle paired with powerful step motor driven in micro-step guarantee high machining precision and repeat accuracy.

PROXXON CAD/CAM software for WINDOWS®

Brief description of software and hardware:
The software is harmonized with mechanics, motors and the control unit of the CNC machine, thus offering the optimum performance.
The CNC control unit controls the step motors of the machine. The PC software provides the machine with the geometry information for travel of the tools (via RS 232 interface). This means that the control unit is the interface between software and the mechanics of the machine.
Powerful micro processors and accordingly dimensioned step motors and phases ensure that the motors always provide enough power for any machining processes. Two freely usable output relays in the casing of the control unit provide facilities for control of additional functions, e.g. a working lamp. Including connection cables with suitable plugs and built-in power supply for connection to 220 - 240V.

Simple creation of work piece geometry
The CAD window is displayed when the programme starts. The work piece contour is created in the familiar WINDOWS® environment. Numerous auxiliary aids help during programme operation, which supports both coordinate entry (absolute and relative) in addition to mouse use.
Technology information is allocated to every drawing element. This makes, for example, different processing speeds and manual tool replacement possible.
Read-in of existing files in .dxf format is possible as well.
Automatic generation of CAM data
The finished drawing of the tool is converted, by a mouse click, into the instruction set for the machine. So, machining can be started immediately. The instruction set generated in this way is in accordance with DIN/ISO 66025 and can be manually edited and exported. Conversely, the system also permits importing or complete self writing of data sets.
Software update for precision lathe PD 400/CNC

CNC simulation
If requested, the travel distances of the tool are simulated in the graphic window. In this way, faults in the programming can be recognised in time.
Manual work
The handwheels are replaced with the step motors of the CNC machine. Nevertheless, manual machining is possible with the help of cursor buttons, since the step motors can be operated manually.
Software installation
The PC software is supplied on a CD ROM. The problem-free installation is effected under WINDOWS® as usual.
Note:
PC or laptop are not part of the scope of delivery. Minimum requirements for the hardware: Pentium processor with 400 MHz frequency (or comparable), high-quality graphic card (64 MB RAM) and at least 40 MB free hard disc storage.

Technical data:

Computer with software
RS 232 interface
MCS-multicontroller
Step motor (X-axis)
Step motor (Z-axis)
Switch X-axis
Switch Z-axis

1. Computer with software
2. RS 232 interface
3. MCS-multicontroller
4. Step motor (X-axis)
5. Step motor (Z-axis)
6. Switch X-axis
7. Switch Z-axis

Thread cutting device for the lathe PD 400/CNC

A complete attachment kit with rotary encoder for the main spindle, belt pulleys, synchronous belts and all required accessory parts.

The software of the PD 400/CNC has already been programmed accordingly: Available now are the standard male threads M 1 to M 42. Special threads of any type (e.g. inch threads) can be manufactured as well with different pitches and thread depths. Including detailed assembly instructions.
NO 24 506

Self-centering 3-jaw chuck
Identical to the lathe chuck of lathe PD 400. Capacity through reversing chucks 3 - 100mm.
NO 24 407

Self-centering 4-jaw chuck
The jaws are not independently adjustable, i.e. they are self-centering. High accuracy. Chuck diameter 100mm.
NO 24 408

Collet attachment with collets for PD 400
For accurate use on round components. One hardened collet each hardened collet 2 - 3 - 4 - 5 - 6 - 8 - 10 - 12 and 14mm are included. Concentric accuracy better than 0.02mm, much better than a chuck. One soft collet for making a custom size yourself. The included collet attachment is mounted in the place of the headstock chuck. Supplied in a wooden box.
NO 24 419 complete

Tool post
Including two holders. Provides quick tool changes with easy height adjustment. For turning tools 10 x 10mm.
NO 24 415

Individual quick-change holder
Fits the tool post of PD 400.
NO 24 416

Die holder for round die.
For threads M 3 - 4 - 5 - 6 - 8 and 10.
With holder Ø 10mm for mounting in the tailstock drill chuck of the lathe. The holder is held by hand while cutting the threads. Neatly packed in wooden box with sliding lid.
NO 24 082

Cutting tools of high quality cobalt HSS steel, ground.
Five piece set
One each roughing out, parting, finishing cut, left and right cutter. Comes in wooden box with sliding lid. 10 x 10 x 80mm.
NO 24 550

Three piece thread cutting set
One cutter for external thread , one for internal thread (both ground to 60°, metric), one general cutting . Supplied in wooden box with sliding lid. 10 x 10 x 80mm.
NO 24 552

Cutter set with tungsten inserts
Three holders (90mm long):
for roughing out;
for longitudinal work;
for 90mm boring bar, holes from 12mm.
Standard tungsten inserts, 55°, plated (commercially available version). Three additional inserts securing screw and key TX 8 are included. 10 x 10mm.
NO 24 556 complete

Tungsten disposable tips (not depicted)
For the holders as described above.
NO 24 557 Ten piece set

Three piece centre drill set
Made of HSS steel. DIN 333 (type A) 60°. Complete set centre drills with sizes of 2.0 - 2.5 and 3.15mm.
NO 24 630

HSS boring tool set, 6 pieces
One each cutter for 60 degree (metric) and 55 degree (Whitworth) inside threads, 1.3mm - 2.65mm and 4mm. Shaft of Ø 6mm. Length 95mm. The cutters are held by a tool holder (9 x 9mm) that mounts to the tool post of either PD 230/E, PD 250/E or PD 400. Comes in wooden box with sliding lid.
NO 24 520