The document discusses tool compensation in machining, emphasizing its importance for manufacturing accurate parts and reducing dimensional errors. It covers various types of tool compensation, such as cutter radius, tool nose radius, and tool length compensation, while detailing the process of calculating tool length compensation using G codes. Additionally, it introduces touch-trigger probes (TTPs) in CNC turning for on-machine measurement and automatic tool compensation, highlighting their operational principles and factors affecting their performance.

1. Machine Tool And Error
Compensation
By:
ARPIT AGARWAL
120929146
7-B-16

2. What is tool compensation??

4. And, why do we really need it?
• Ability to manufacture accurate parts
• Dimensional errors can be immediately detected and avoided
• The world market for machine tools in 2007 is estimated to be 71
billion US dollars, which represents a growth of 18% compared to
2006.

5. Top 10 machine tool producing countries

6. Types of tool compensation
• Cutter Radius(or Diameter) Compensation
• Tool Nose Radius Compensation
• Tool Length Compensation

7. Tool Diameter Compensation

17. Cutter radius compensation video
https://www.youtube.com/watch?v=MW0WfKkre
Hs

18. Tool Nose Radius Compensation

28. Tool Length Compensation

29. Why Tool Length Compensation is Needed
• No Two Tools Will Have Exactly the Same Length
• Tool’s Length Will Vary from Each Time it is Assembled
• Tool Data is Entered Separately from the Program
• Sizing and Trial Machining Must Often be Done

31. Tool length compensation G Codes

33. Calculating tool length compensation

34. • Make the workholding setup and load a workpiece - Program zero will be
the top surface of the workpiece.
• Send the machine to the Z-axis zero return position and reset (set to zero)
the Z-axis relative display - This sets the point of reference for your
measurement.
• Load a tool to be measured and manually bring the tip of the tool to the Z
axis program zero surface -Using incremental jog and/or handwheel,
cautiously bring the tool tip to the program zero surface. The Z-axis display
follows along. With the tool tip touching the workpiece coordinate system
zero surface in Z, the Z-axis relative position display will be showing you the
tool length compensation value for this tool. This is the value that must be
entered into the tool length compensation offset register.

38. Tool & Error Compensation by Means of Touch
Trigger Probes in CNC Turning

39. • The current demand for high quality products has lead to the necessity
of a total dimensional control of workpieces produced in order to avoid
dimensional errors. Inspection techniques were developed and
progressively integrated into machine tools leading to the on-machine-
measuring (OMM) concept. Among other methods, touch-trigger-
probes (TTPs) inspired on CMMs were adopted.
• Nowadays, manufacturers offer machine-tools equipped with TTP for
both tool compensation and workpiece measurement at reasonable
costs.
• The working principle of a TTP is based on the emission of an electrical
signal when physical contact with a probe is produced. This named
trigger signal is converted by an interface to be read by the CNC control
instantaneously and translated into coordinates referred to the machine
zero point.

40. • A TTP for measurement of workpieces consist of a turret-mounted touch
probe with a stylus ball tip. This type of probe is mainly used for setting up
the machining cycle, for on-process part inspection for tolerance control
with feedback for automatic tool compensation and, sometimes, for on-
machine final part inspection.
• For presetting of tools by using a turret TTP it is necessary to select the
tool and perform a cylindrical turning of a surface. Next, diameter of the
machined surface has to be measured with the turret TTP and the
difference between obtained and expected dimension is used for
calculating the tool compensation. The turret TTP automatically registers
this value into the tool table of the CNC controller. This procedure has to
be repeated for each tool to be used.

41. Factors affecting TTPs
• Geometric lathe misalignments
• Thermal drift
• Repeatability of TTPs

42. A video on TTP
•
https://www.youtube.com/watch?v=QB_Noh6M0m8
(second last slide)

43. Thanks for bearing with me!
• And, congrats to all my TCS buddies ^_^