1. Twist Measurement Strategy
Cylinder Map (Twist)
Cylinder Map (Twist)
Available on Certain Talyronds Only.
A Suitable Software Licence is Required.
Talymap Twist analysis required.
What is Twist ?
Twist Measurement Strategy
Set Up Component and Instrument
Measurement & Data Export Settings
Measure Vertical Traces & Export Data
View and Analyse Results
Twist Parameter Definitions

2. Cylinder Map (Twist)
What is Twist ?
Twist is similar to the effect of a screw thread being present on a shaft.
Twist affects the effectiveness and the lifetime of the seals placed in contact with the shaft causing leakage (or retention) due to pumping action or dry-running, leading to premature failure.
Typically the analysed twist surface wavelength is <0.4mm in length, inline with the size of the lipped polymer seal.
Retention of liquid example shown above

3. What is Twist? developed and patented by Daimler-Chrysler AG
Cylinder Map (Twist)
What is Twist?
Twist analysis is a method of quantifying the twist on the shaft.
developed and patented by Daimler-Chrysler AG
uses an 3D Cylinder map of the surface
measurements can be taken with suitable Talyrond instruments
existing methods are based on the use of a weighted string. The shaft is turned in both directions and the distances moved noted.

4. Twist Measurement Strategy
Cylinder Map (Twist)
Twist Measurement Strategy
Axial extent
The axial extent of the data should be sufficient to cover the area of interest (where the seal is going to contact the shaft).
It should be greater than 2mm and no less than 4000 points (see Level 2 Standard extract).
Note, Required data spacing of 0.5µm
On an unknown twist quantity, two measurements are initially required.
Radial extent
Data must be taken using 72 traces spaced at either 5 or 0.5 degree intervals (covering 360 or 36 degrees measurement angle).
Use 5 degree spacing for measuring components with a low number (<15) of starts per revolution.
Use 0.5 degree spacing for measuring components with a high number (≥15) of starts per revolution.
Extract from Daimler standard shown right

5. Set Up Component and Instrument
Cylinder Map (Twist )
Set Up Component and Instrument
CYLINDER MAP
Multiple Straightness Measurements
Export 3D ‘*.sur’ File to TalyMap
& / or

6. Set Up Component and Instrument
Cylinder Map (Twist )
Set Up Component and Instrument
Prior to Measurement
Calibrate Talyrond using 2µm or 5µm diamond stylus
Stylus force set to <1g using Correx gauge.

7. Set Up Component and Instrument
Cylinder Map (Twist)
Set Up Component and Instrument
Important: Centre / Level Component Well
Start (θ)
Start (Z)
Data Length R
Move Arm into Contact  Calibrate Arm (UCS) to Component Radius (R)
Calibrate Column (UCS) to Component Start (Z)  0mm
Rotate Spindle To Start (θ) 

8. Measurement & Data Export Settings
Cylinder Map (Twist)
Measurement & Data Export Settings
Select Measurement Type (Cylinder Map) 
Press
Complete Dialogue  OK 

9. Measurement & Data Export Settings
Cylinder Map (Twist)
Measurement & Data Export Settings
Choose ‘Measure’ Tab  Enter Measurement Name or Select Auto-Name as Required 
MEASUREMENT NAMING

10. Measurement & Data Export Settings
Cylinder Map (Twist)
Measurement & Data Export Settings
Choose ‘Export’ Tab  Choose Destination Folder & File as Required 
EXPORT SETTINGS
Deselect ‘Delete After Export’ to Retain Individual Straightness Results in ULTRA Database

11. Measurement & Data Export Settings
Cylinder Map (Twist)
Measurement & Data Export Settings
Choose ‘Z-Axis’ Tab  Enter Vertical Measurement Details as shown 
COLUMN SETTINGS
Gauge Range reduced to 0.41mm giving a resolution of 6.4nm

12. Measurement & Data Export Settings
Cylinder Map (Twist)
Measurement & Data Export Settings
Choose ‘C-Axis’ Tab  Enter No. of Traces, Trace Spacing & Measurement Direction 
SPINDLE SETTINGS SHOWN FOR THE TWO MEASUREMENTS INITIALLY REQUIRED
Enter Comments if Required  Press OK 

13. Measure Vertical Traces & Export Data
Cylinder Map (Twist)
Measure Vertical Traces & Export Data
Wait for Straightness Measurements & Data Export to Complete 
Measurement Progress Indication:
Data Export Progress Indication:

14. View and Analyse Results
Cylinder Map (Twist)
View and Analyse Results
Open TalyMap  File  Open a the Studiable 

15. View and Analyse Results
Cylinder Map (Twist)
View and Analyse Results
Operators  Rotations  Clockwise rotation of 90°
OK 

16. View and Analyse Results
Cylinder Map (Twist)
View and Analyse Results
Highlight Rotated Study in Talymap  Lead Analysis (Twist)  OR

17. View and Analyse Results
Cylinder Map (Twist)
View and Analyse Results
Ensure Part Diameter Correct  Ensure Area of Twist is encompassed within box 
OK 

18. View and Analyse Results
Cylinder Map (Twist)
View and Analyse Results
Daimler Chrysler Patented Analysis Displayed by Talymap

19. Twist Lead parameters Definitions
Cylinder Map (Twist)
Twist Lead parameters Definitions
Lead angle Dγ
( º & ´ )
The signed angle of a lead structure, right (+ sign) and left (- sign) turn
Lead depth Dt
(µm)
The height between the wave peak and valley
Number of threads DG
Number of periods
Period length DP
(mm)
The wavelength between two successive wave peaks/valleys

20. Twist Lead parameters (continued)
Cylinder Map (Twist)
Twist Lead parameters (continued)
Theoretical supply cross section DF
(µm²)
The cross-sectional area over a period length
Theoretical supply cross section per turn DFu
(µm²)/U
The cross-sectional area over the whole evaluation length, equal to DF*DG
Contact length DLu
(%)
The contact length in percent corresponding to the section height at the 80% material ratio

21. Twist Measurement Strategy
Cylinder Map (Twist)
Cylinder Map (Twist)
Available on Certain Talyronds Only.
A Suitable Software Licence is Required.
Talymap Twist analysis required.
What is Twist ?
Twist Measurement Strategy
Set Up Component and Instrument
Measurement & Data Export Settings
Measure Vertical Traces & Export Data
View and Analyse Results
Twist Parameter Definitions