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2.1 Introduction :

The shaper is a single point tools and cut only in straight lines. They bothmake the same types of cuts. The shaper handles relatively small work.

The planer handles work weighing up to several tons. Moving the tool

bit attached to the ram makes the cutting stroke of the shaper. The

cutting stroke of the planer is achieved by moving the work past a

stationary tool bit. The types of cuts which can be made with eithermachine. They rapidly fell out of favor with modern industry as they

were time consuming in operation, the amount of material removal by a

single point cutting tool being no match for recent methods, howeverthey are still popular with some materials, or where production time is

not a factor. The basic function of the machine is still sound and tooling

for them is minimal and very cheap to reproduce. They can be invaluable

for jobbing or repair shops where only one or a few pieces are requiredto be produced and the alternative methods are cost or tooling intensive.

The mechanically operated machines are simple and hard in

construction, making their repair and upkeep easily achievable.

Fig.2.1 shaping machine

http://en.wikipedia.org/wiki/Tool_bithttp://en.wikipedia.org/wiki/Tool_bit

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Shaping is important working methods for the manufacture of plane and curved

surfaces. Fig 2.2

Fig.2.2 types of cut

The chips are cut off in strips from the work piece by the straight main stroke,

fig. For machining short or long work pieces there are shaping machines of

various designs.

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Fig. 2.3 Cutting off ships during shaping process

2.2 Main shaping motion:

The- main or cutting motion (a&b) is performed by the shaping tool.There is a difference between working stroke and non-cutting stroke.During the working stroke (forward stroke) the chips are cut, off. During

the non-cutting stroke (backward stroke), the tool travels backwards

without cutting the material. Both strokes together form a cycle.

The feed motion (c) produces the chip thickness. For shaping in

horizontal direction, the clamped workpiece is moved against the tool.For shaping in vertical direction I the tool must be moved towards the

workpiece.

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The setting of the tool (d) produces the cutting depth. During the

horizontal shaping Processes, it. Is achieved moving. the tool

downwards. During the vertical soaping processes by moving the

workpiece side ways. Fig ( 2.4).

Fig.2.4 main motion of shaping

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2.3 Types of shaping machine and main part :

Shapers are mainly classified as standard, draw-cut, horizontal,

universal, vertical, geared, crank, hydraulic, contour and traveling head.

The horizontal arrangement is the most common. Vertical shapers aregenerally fitted with a rotary table to enable curved surfaces to be

machined. The vertical shaper differs from a slotter (slotting machine),

as the slide can be moved from the vertical. A slotter is fixed in the

vertical plane.

Very small machines have been successfully made to operate by hand

power. Once size increases, up to a potential 36 inch stroke, the power

needs increase and it becomes necessary to use an electric motor. This

motor drives a mechanical arrangement (using a pinion gear, bull gear

and crank) or a hydraulic motor which supplies the necessary movement

via hydraulic cylinders.

2.3. Types of shaping machine:

2.3.1 Horizontal shaper:

Shaper size:The size of a shaper is the maximum length of stroke, which it can take.

Horizontal shapers are most often made with strokes from 16 to 24strokes inches long, though some smaller and larger sizes are available.

These shapers use from 2 to 5 HP motors to drive the head and the

automatic feed.

Shaper Width:The maximum width, which can be cut, depends on the available

movement of the table. Most shapers have a width capacity equal to or

greater than the length of the stroke. The maximum vertical height

available is about 12 to 15 inches.

The main parts of Horizontal Shaper:

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The main part of Horizontal shaper are shown in Figure (2.5).

Fig .2.5 Main component of Horizontal Shaper

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Table 2.1 main parts of the Horizontal Shaper.Parts name Parts name

1- Tool holder.

2- Hinged tool pivot.

3- Vertical feed handle.4- Vertical feed base.5- Bolt.6- Ram.

7- Ram fastening handle.

8- Stroke length ruler.9- Cutting tool.

10- Table fastening angle.11- Shaper base.

12- Table.13- Table movement

handle.

14- Horizontal feed handle.

15- Vertical feed boIt.

16- Feed arm.17- Feed adjustment.18- Stoke length pivot.19- Ram rear part.

20- Operating arm.

21- Speed change arms.22- Main motor.

23- Stroke position fastener.

The main parts of horizontal shaper are:

Ram:

The ram slides back and forth in dovetail or square ways to transmit

power to the cutter. The starting point and the length of the stroke can be

adjusted.

Tool head:The tool head is fastened to the ram on a circular plate so that it can be

rotated for making angular cuts. The tool head can also be moved up ordown by its hand crank for precise depth adjustments. Attached to the

tool head is the tool holding section. This has a tool post very similar to

that used on the engine lathe. The block holding the tool post can berotated a few degrees so that the cutter may be properly positioned in the

cut.

Clapper Box:

The dapper box is needed because the cutter drags over the work on the return stroke. The dapper box is hinged so that the cutting tool will not

digin. Often this dapper box is automatically raised by mechanical, air,

or hydraulic action.

Table :

The table is moved left and right, usually by' hand, to position the workImder the cutter when setting up. Then" either by hand or more often

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automatically, the table is moved sideways to feed the work under the

cutter at the end or beginning of each stroke.

Saddle:.

The saddle moves up and down (Y-axis), usually manually, to set therough position of the depth of cut. The hand crank on the tool head can

set final depth.

Column:

The column supports the ram and the rails for the saddle. Themechanism for moving the ram and table is housed inside the column.

Tool holders:

Tool holders are the same as the ones used on an engine lathe, though

often larger in size. The cutter is sharpened with rake and clearance

angles similar to lathe tools, though the angles are smaller because the

work surface is usually flat. These cutters are fastened into the tool

holder, just as in the lathe, but in a vertical plane.

2.3.2 Vertical Shapers:

The vertical shaper, sometimes called a slotted, has a vertical ram, with

table and saddle similar to the horizontal shaper. If a rotary table ismounted on the regular table, a number of slots can be made at quite

accurately spaced intervals. This machine can work either outside or

inside a part, provided that the interior opening is larger than the toolhead. A schematic illustration of a vertical shaper is shown in Figure

(2.6).

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Fig.2.6 Vertical Shaper Machine.

2.4 Feed drive & cutting speed:

2.4.1 Feeding on shaper:

Feeding:Horizontal feeding done by speed box in the end of cut term, value of

feeding adjustment by (Term / mm) The direction of feeding depend on

type of cut blade which used if we have right blade feed it will be fightway Vice versa.

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The feed drive:

The feed motion has to be timed to the end of the backward stroke, while

manipulating the feed spindle by hand; rough work surfaces can resultfrom uneven turning of hand wheels. This disadvantage is avoided by the

positive feed. A gear with guiding T-slot. The gear shafts drive Figure

2.7. In the slot, a bolt can be shifted and locked in any position. A ratchet

wheel is mounted on the spindle of the table. A pawl engages with the

teeth of the ratchet wheel. Bolt and pawl are connected by a connectingrod. During the forward motion, the later imparts a short rotary motion to

the ratchet Wheel by actuating the pawl, which transmits the motion to

the screw spindle of the table. During farther movement of the gear the

connecting rod moves back again, while the chamfer pawl slides over the

ratchet wheel and meshes again between two teeth. By turning the pawl

1800 the feed direction can be reversed. Shifting the bolt can set the

amount of feed. During the roughing operation the pawl shifts the ratchetwheel by several teeth and during fInishing operations tooth by tooth. As

a result of the adjustable height of the table, the connecting rod should

have variable length. By another connecting rod, the gear can be

swiveled to achieve an equal distance to the table.

Operating method of the fed drive, a) gear with guiding slot, b) bolt c)-

ratchet wheel, d) pawl e) , h) connecting rods, F) spindle of table andg)table as shown in figure (2.7).

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Fig. 2.7 The feed drive.

2.4.2 Cutting Speed and Feed:

The cutting speed of the hydraulic shaper is infmitely variable by means

of hydraulic controls, as is the cross feed. The hydraulic controls, as is

the cross feed. The reverse stroke is made faster than the power stroke

because of the smaller area in the return side of the cylinder, if a constant

volume pump is used.

Cutting Speed:

The cutting speed of the tool across the work will vary during the stroke.

The maximum is at the center of the stroke. However, if the cutting

speed chosen is somewhat on the slow side, the average speed may be

used, and computations are greatly simplified. Although the ratio variessomewhat, several shapers have a linkage using 220 degrees of the cycle

for the cutting stroke and 140 degrees for return stroke this is close to a

3:2 ratio.

In setting up a mechanically operated shaper, the length of cut (in inches)is known, and the cutting speed (in feet per minute) is selected according

to the kind of metal being cut. It is then necessary to compute the strokes

per minute since that is how the shaper speed is controlled. Such

calculations are beyond the scope of this text. The stroke per minute

available on a shaper will vary according to the size of the shaper. The

larger shapers will have lower speeds. A 16-inch shaper may havespeeds of 27 to 150 strokes per minute, while a 24-inch shaper will have

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10 to 90 strokes per minute speeds available. Figure (2.8) . Shows the

graphical representation of the speeds during shaper Process.

Fig.2.8 Graphical representation of the speeds during shaper process .

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2.4.2.1 Cutting Feed:

Feed per stroke on a shaper is comparable to the feed per revolution on a

lathe. Coarse feeds for roughing range up to 0.100 inch per stroke, and

finish cuts from 0.005 to 0.015 inch per stroke. Finish would also dependon the nose radius of the cutting tool.

2.4.2.2 Length of stroke:

The length of stroke is adjusted by shifting the pivot of the gear. Thereturn stroke of the ram takes a shorter time than the forward stroke as

shown in figure (2.9). During the maximum stroke the pivot must be

located at maximum distance from the centre of the gear. The pivot then

covers the distance from A to B (angel a) during the working stroke and

the distance from B to A (angle j3) during the return stroke, Angle a is

bigger than angle j3. Therefore, the working stroke takes longer than the

non-cutting stroke. This is useful because during the reversing stroke nowork will be done.

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Fig .2.9 Adjusting the length of the stroke.

2.5. Cutting Tools:

2.5.1 Angles on the cutting edge:Angles on the cutting edge of the planning tool are

. Clearance angle.

. Wedge angle.

. Rake angle.

These angles showing in figure (2.10).

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Fig.2.10 Angles on the cutting edge,( a) clearance angle, (/l)Wedge

angle,( r) Rake angle.

2.5.2. Roughing tools:

Roughing tools are supposed to cut off as much material as possible

within a short time. The large cross- sections of the chip; require a sturdycutting edge, Figure 2.11 shows roughing tools, a)- straight left hand

tool, b)- straight right hand tool)- cranked left hand tool, d)- cranked

right hand tool.

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Fig. 3.11 Roughing tool, (a) straight left hand tool, (b) straight right hand

tool, (c) cranked left hand tool, (d) cranked right hand tool.

2.5.3 Finishing tools:

Finishing tools must produce smooth surfaces on the work piecesTherefore, the cutting edges are rounded off or the tools have a broad

edge. A gooseneck tool does not press on to the surface at the impact of

a hard spot on the work piece. In this way, the surface damage is

eliminated as shown in figure (2.12).

Fig.2.12 Finishing tools, (a) pointed tool, (b) broad tool, (c) Straight tool,

(d)Goose-neck tool.

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2.5.4 Various shapes of shaping tools:

Various shapes of shaping tools, a) grooving tool, b) side tool, c) bent

Tee-slot cutting tool, d) round nose too1.

Fig.2.13 Various shapes of shaping tools, (a) grooving tool, (b) side tool,

(c)bent Tee-slot cutting tool, (d) round nose tool.

2.6 Clamping of tools and workpiece.

2.6.1 Clamping of tools:To prevent springing of the tool, it has to be clamped as short as possible

figure (2.14) During horizontal shaping the tool is clamped verticallytowards the work piece. During this operation the clapper is lifted up

during the reverse stroke. While shaping vertical faces or inclined facesrequiring motion with the too slide, the clapper box has to be swiveled

away from the surface to be machined. This helps the tool to lift off the

surface during the backward stroke. Figure (2.15) Setting of the tool for

angular planning and vertical planning.

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Fig. 2.14 Clamping of tools.

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Fig.2.15 Setting of the tool.

2.6.2 Clamping of work pieces:

Clamping the work piece on the table or in the vice produces a strong

grip. This grip prevents shifting of the work piece during the forward

stroke. The strength of grip increases with the roughness of the surface tobe clamped and with the clamping force. The latter, however, must not

be too big; otherwise the danger exists that thin work pieces may bend.

The surface to be clamped must be sufficiently large. If the surface is too

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small, the pressure per square unit becomes too large, which may

produce pressure marks on the finished surface. Chips and other

impurities will affect the clamping; therefore, the surfaces to be clamped

must be cleaned before.

2.6.2.1 Small work pieces clamping:Small work pieces should be clamped in the machine vice, figure (2.16)

the work piece is lifted up a little when the movable jaw of the vice is

tightened. Therefore, the work piece must be hammered back by means

of a plastic hammer. Parallel block facilitate the aligning and clamping.However, they must not hamper measuring and checking during

machining. Clamping in the machine vice. Large work pieces are

clamped on the machine table.

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Fig. 2.16 Clamping small work pieces.

2.6.2.2 Clamping on the machine table:

The heads of the T-bolts must fit properly in the T-slots. The clamptransmits the clamping force to the work piece. It must be adjusted parallel

to the clamping surface, thus the bearing surface is made large enough. TheT- bolts should be located close .to the work piece so that the lever

affects alarge clamping force. If it is not possible to clamp a work piece

as described bove, it is mounted on the table by means of stoppers and

gripping devices Figure (2.17) .

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Fig.2.17 Clamping on the machine,(a) good bearing surface, (b) bad

bearing urface, (c) adjustable gripping device, (d) stepped block as

support.

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Fig.2.18 Clamping of thin work pieces,(a) contact edge,(b) work

piece,(c)clamping plate,( d) clamp dog with screw,( e) stopper.

Fig.2.19 The clamping of several work pieces using machine table