TP20 probe modules

This section covers the use and care of the TP20 probe modules for the RTP20.

Introduction

The Renishaw TP20 probe modules incorporate a kinematic coupling, which ensures highly repeatable stylus tip positioning.

The range of modules comprises 5-way versions with length or trigger force options and a 6-way version.

Probe modules fit directly onto the RTP20 kinematic mount. It is possible to change TP20 modules with different stylus configurations without re-qualification.

Specification

Product compatibility

The TP20 is suitable for use with all Renishaw probe interfaces and probe heads which service the TP2 and TP6 touch-trigger probes.

Diameter

13.2 mm

Length:

 

LF / SF / MF / EF

38 mm

EM1 STD

88 mm 

EM2 STD

113 mm

6-way

42 mm

Probe module mounting

TP20 kinematic

Stylus mount

Thread M2 × 0.4

Sense directions:

 

LF / SF / MF / EF / EM1 STD / EM2 STD

5-way (±X, ±Y, +Z)

6-way

6-way (±X, ±Y, ±Z)

Probe module pull-off force

10 N (1 kgf), 36 ozf maximum

Sealing

IP30

Probe module life

25,000 changes

Probe module type and stylus length 

Parameter

LF

SF

MF

EF

6-way

EM1 STD

EM2 STD

Stylus length

10 mm

10 mm

25 mm

50 mm

10 mm

10 mm

10 mm

Trigger force
(nominal at stylus tip) XY

0.055 N
(5.5 gf)

0.08 N
(8 gf)

0.1 N
(10 gf)

0.1 N
(10 gf)

0.14 N
(14 gf)

0.08 N
(8 gf)

0.08 N
(8 gf)

Trigger force
(nominal at stylus tip) Z

0.65 N
(65 gf)

0.75 N
(75 gf)

1.9 N
(190 gf)

3.2 N
(320 gf)

1.6 N
(160 gf)

0.75 N
(75 gf)

0.75 N
(75 gf)

Overtravel force
(max. at stylus tip) XY

0.09 N
(9 gf)

0.2 N - 0.3 N
(20 gf - 30 gf)

0.2 N - 0.4 N
(20 gf - 40 gf)

0.2 N - 0.5 N
(20 gf - 50 gf)

0.25 N
(25 gf)

0.2 N - 0.3 N
(20 gf - 30 gf)

0.2 N - 0.3 N
(20 gf - 30 gf)

Overtravel force
(max. at stylus tip) +Z

1.1 N
(115 gf)

3.5 N
(350 gf)

7 N
(700 gf)

10 N
(1 kgf)

2.5 N
(250 gf)

3.5 N
(350 gf)

3.5 N
(350 gf)

Overtravel force
(max. at stylus tip) -Z

-

-

-

-

9 N
(900 gf)

-

-

Overtravel displacement XY*

±14°

±14°

±14°

±14°

±14°

±14°

±14°

Overtravel displacement +Z

3.1 mm

4 mm

3.7 mm

2.4 mm

4.5 mm

4 mm

4 mm

Overtravel displacement -Z

-

-

-

-

1.5 mm

-

-

* The probe module may detach if this value is exceeded

NOTE: The use of cranked styli with RTP20 is not recommended.

Probe module changing repeatability

Probe module changing method

Repeatability

Automatic changing

1 μm

Manual changing

2 μm

Measuring performance

NOTE: The following data is derived from high accuracy test rig measurements and may not represent the performance achievable on a CMM. Please consult your CMM supplier for overall system accuracy information.

Performance at 10 mm stylus length:

Parameter

LF

SF

MF

EF

6-way

EM1 STD

EM2 STD

Unidirectional repeatability* (2σ)

0.35 μm

0.35 μm

0.50 μm

0.65 μm

0.8 μm

0.35 μm

0.35 m

2D (XY) form measurement deviation*

±0.6 μm

±0.8 μm

±1 μm

±2 μm

±1.5 μm

±0.8 μm

±0.8 μm

* Measured at a trigger speed of 8 mm/s

Test stylus ball diameter 4 mm

The probe module

Each probe module houses the touch-trigger mechanism that carries the stylus assembly. The module provides overtravel in the X, Y and Z axes. The M2 stylus mounting is compatible with Renishaw's comprehensive range of M2 styli.

Electrical contact pins automatically complete the probe circuit.

TP20 module selector

Seven versions of the TP20 probe module can be used with the RTP20, they can be identified by the end cap colour.

  1. Low force (LF) probe module (green cap)
  2. Standard force (SF) probe module (black cap)
  3. Medium force (MF) probe module (grey cap)
  4. Extended force (EF) probe module (brown cap)
  5. 6-way (6W) probe module (blue cap)
  6. Extension module 1 standard force (EM1 STD) (black cap)
  7. Extension module 2 standard force (EM2 STD) (black cap)

Medium and extended force modules are used to overcome the effects of false triggers, caused either by stylus length and mass, or vibration caused by machine acceleration forces.

The low force module permits the measurement of delicate objects.

The EM1 and EM2 extended modules allow access to otherwise inaccessible workpiece features. Both operate using standard force and offer better measuring performance than using long styli with SF, MF, LF or EF modules.

The TP20 6-way senses in the +Z and -Z directions, allowing undercuts to be checked.

RTP20 user guide - section 6.4

Module

Minimum stylus length

Maximum stylus length

Overall reach

Low force (LF)

10 mm (0.39 in)

 30 mm (1.18 in)

 94 mm (3.70 in)

Standard force (SF)

10 mm (0.39 in)

 50 mm (1.97 in)

 114 mm (4.49 in)

Medium force (MF)

10 mm (0.39 in)

60 mm (2.36 in)

124 mm (4.88 in)

Extended force (EF)

10 mm (0.39 in)

60 mm (2.36 in)

124 mm (4.88 in)

6-way

10 mm (0.39 in)

30 mm (1.18 in)

98 mm (3.86 in)

EM1

10 mm (0.39 in)

50 mm (1.97 in)

143 mm (5.63 in)

EM2

10 mm (0.39 in)

50 mm (1.97 in)

168 mm (6.61 in)

TP20 installation

Assembling the probe module and stylus

  1. Select the probe module with the correct trigger force rating for the application (see 'TP20 module selector' section).
  2. Fit the stylus to the probe module, first hand tightening then using the S7 stylus tool (supplied) for final tightness. Renishaw GF styli require an S20 spanner. The recommended tightening torque is 0.05 Nm to 0.15 Nm (0.04 lb ft to 0.11 lb ft). Torque must not exceed 0.3 Nm (0.22 lb ft).

RTP20 user guide - section 6.5.1 

Fitting the probe module with stylus on the RTP20

  1. Examine all mating faces for cleanliness. Where necessary, clean the surfaces with the Renishaw CK200 kit (supplied).
  2. The TP20 module and kinematic mount are marked with three unique alignment marks. When offering the TP20 up to the probe head, ensure that similar marks are aligned with each other. Allow the TP20 body to engage under magnetic force.

RTP20 user guide - section 6.5.2