theory of machines: shaper feed mechanism

Shaper Feed Mechanism

Contents

• General Description.• 3D overview for mechanism.• Motion Description.• Data Analysis.• Application of mechanism in industry.• Conclusion.

General Description • It’s a machine that can make

slots and grooves using a thin cutting tool

• The linear cutting motion is provided by the “Quick-Return Mechanism“.while the feed motion is supplied by the mechanism illustrated in this report "The shaper feed Mechanism".

General Description

• The shaping machine is used to machine flat metal surfaces especially where a large amount of metal has to be removed.

• It can cut curves, angles and many other shapes. It is a popular machine in a workshop because its movement is very simple although it can produce a variety of work.

• When high accuracy and surface quality are required, shaping is followed by other techniques, e.g. grinding or scraping.

Components

3D Overview of the mechanism

3D Overview of the mechanism

Solidworks

Degrees of Freedom

Note That:

1 , 2 , 3 , 4 represent no. of links

a, b , c , d represent no. of joints

According to formula :

M = 3(n-1)-2j1-j2.

N=4 j1=4 j2=0

D.O.F = 1

Notice: Four bar mechanism.

Position Analysis

Extreme Right Position = L-R

Position Analysis

Extreme Left Position = L+R

Velocity Analysis

Velocity Analysis

Velocity Analysis• In our case:

S= 27 mm• R= 77 mm• = 27÷77 = 0.35 rad = 20⁰Ө• Assume P= 2mm• S (feed)= 20×2/360 = 0.11mm/rev

Velocity Analysis• How to increase/ decrease the feed?

• By changing the length L (the overset distance of the link A), the ratchet stroke will change and therefore the number of teeth moving per stroke.

• i.e By increasing the ratchet stroke, the ratchet will move 2 teeth instead of one per stroke which results in increasing the feed rate.

Velocity Analysis• How to increase/ decrease the feed?

To calculate the feed rate in (mm/min) we will use the following formula: F=S*N ,where F is feed rate in mm/min.

S is feed rate in mm/rev.

N is the input velocity obtained from the gear box in rpm.

Matlab Data

Applications in Industry

Conclusion

• We can conclude that the feed mechanism is an essential mechanism in any shaper machine.

• One main feature is that it links the motor rotation which feeds the quick return mechanism with the table feed.

• We could change the feed independently by changing the offset distance of the link.

Thanks for your attention