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SH25 stylus holder range metrology performance
SH25-2A, SH25-3A and SH25-4A have distinct metrology advantages over SH25-2, SH25-3 and SH25-4 for any stylus arrangements where the stylus holder is subjected to torsional load when using components like cranked styli or knuckle joints.
The standard range of SH25 stylus holders still have an advantage over the -A range of stylus holders when straight styli arrangements are required.
The following tables compare typical metrology performance with the standard and -A range of SH25 stylus holders for both straight and cranked stylus configurations.
SH25-2 against SH25-2A - bi-directional ring gauge scan test
Straight stylus perfromance - effective stylus reach 51 mm:
Stylus holder | SPAN data raw | SPAN data filtered | Stylus tip deflection |
|---|---|---|---|
SH25-2 | 1.6 µm | 1.2 µm | 0.2 mm |
SH25-2A | 1.5 µm | 1.1 µm | 0.2 mm |
Cranked stylus performance - crank down distance 55 mm, crank out distance 83 mm:
Stylus holder | SPAN data raw | SPAN data filtered | Stylus tip deflection |
|---|---|---|---|
SH25-2 | 14.9 µm | 5.9 µm | 0.35 mm |
SH25-2A | 4.1 µm | 2.4 µm | 0.35 mm |
SH25-3 against SH25-3A - bi-directional ring gauge scan test
Straight stylus perfromance - effective stylus reach 121 mm:
Stylus holder | SPAN data raw | SPAN data filtered | Stylus tip deflection |
|---|---|---|---|
SH25-3 | 2.2 µm | 1.3 µm | 0.2 mm |
SH25-3A | 2.5 µm | 1.7 µm | 0.2 mm |
Cranked stylus performance - crank down distance 125 mm, crank out distance 83 mm:
Stylus holder | SPAN data raw | SPAN data filtered | Stylus tip deflection |
|---|---|---|---|
SH25-3 | 11.8 µm | 8.2 µm | 0.35 mm |
SH25-3A | 3.5 µm | 2.1 µm | 0.35 mm |
SH25-4 against SH25-4A - bi-directional ring gauge scan test
Straight stylus perfromance - effective stylus reach 221 mm:
Stylus holder | SPAN data raw | SPAN data filtered | Stylus tip deflection |
|---|---|---|---|
SH25-4 | 3.0 µm | 1.7 µm | 0.2 mm |
SH25-4A | 3.5 µm | 2.4 µm | 0.2 mm |
Cranked styus performance - crank down distance 225 mm, crank out distance 83 mm:
Stylus holder | SPAN data raw | SPAN data filtered | Stylus tip deflection |
|---|---|---|---|
SH25-4 | 15.7 µm | 5.0 µm | 0.35 mm |
SH25-4A | 5.1 µm | 2.4 µm | 0.35 mm |
Test setup criteria
Test site | Renishaw UK |
|---|---|
Styli used | Renishaw's M3 stylus range |
CMM specification | U3 = 0.48 µm + L / 1000 |
CMM controller | Renishaw's UCC2 |
Probe calibration | Renishaw's third order polynomial calibration method |
Data filter used | Harmonic simple cut off order = 60 UPR (undulations per revolution) |
Artefacts used | Ø25 mm (nom) calibration sphere (for the ISO 10360 Part 2 / Part 4 tests) Ø50 mm (nom) ring gauge (for the ring gauge scan tests) |
Scanning speed | 5 mm/s (for the ISO 10360 Part 4 and ring gauge scan tests) |
Touch speed | 5 mm/s (for the ISO 10360 Part 2 tests) |
Back off speed | 1 mm/s (for the ISO 10360 Part 2 tests) |
Bi-directional scans | The effect of probe misalignment and contact friction will result in radius changes with scanning direction if a suitable calibration procedure is not used. Mechanical hysteresis within a probe mechanism is best demonstrated by a bi-directional scan. Therefore, Renishaw have decided to take the high integrity approach of quoting ring gauge metrology using bi-directional scan data to demonstrate the performance of the Renishaw probe and calibration method. |