Six degrees of freedom of a body/object in space

1
Work Holding and Tool Holding

• Six degrees of freedom of a body/object in space
• Principle of work/tool holding (location and
  restraint)
• Example of work holding method

2
Six degrees of freedom

• If we consider a body/object in space it is free
  to move in six directions as follows
• Back and forth along the X axis
• Side to side along the Y axis
• Up and down in the Z axis
• Rotate either way about the X axis
• Rotate either way about the Y axis
• Rotate either way about the Z axis

3
Principle of location and restraint

• To be able to carry out work on the
  material/object it is necessary to locate the
  material in a set position on the machine and
  restrain it using some form of clamping/fixing
  device to prevent any linear or rotational
  movement.
• The clamping/fixing devices can consist of
• (A) positive restraints, where a physical object
  prevents the material from moving.
• (B) frictional restraints, where the material is
  gripped between two or more objects.
• (C) a combination of positive and frictional
  restraints.
• Where possible a positive restraint should be
  used to resist cutting forces.

4
Location and Restraint

• If the material is placed on a flat surface as in
  diagram below some of its states of freedom
  become restrained

5
When location pins are added as in diagram below
it becomes further restrained and also located in
set positions
6
If clamping screws are then added as in diagram
below the material becomes fully restrained and
located in set positions
7
Typical Example of a Work Holding Device (work
held between centres on a lathe)