Synopsis

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Surface roughness and roundness are important factors in many precision machined and finished products. Understanding and measuring surface roughness requires strong fundamental knowledge about the roughness tester, roughness parameters, instrument settings, and interpretation of the roughness data according to roughness standards. Measurement of roundness requires basic understanding of the definitions of roundness and methods of quantifying roughness. 

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In aim of this workshop is to complement the practical knowledge and experience of the participants with a sound understanding of the meaning of the parameters that they measure, the relationship between surface preparation with surface texture, instrument setting such as cut-off value, etc. The participants will learn the principles of roughness, waviness and form, stylus-type roughness instruments, amplitude, hybrid and functional roughness parameters, as well as basic calculations involving the most widely used roughness parameter, namely the average roughness Ra. Actual 2-D profile data obtained from machined parts will be used to help the participants understand the effect of machining parameter and tool condition on the surface roughness. The participants will learn how to use a vision-based method to capture and analyse 2-D profile of cylindrical surfaces.

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The participants will also learn how to evaluate roughness using four different methods, namely least-squares circle (LSC) method, maximum inscribing circle (MIC) method, minimum circumscribing circle (MCC) method, and minimum zone reference (MZC) circle method. Real data obtained using a roundness tester will be used in the analysis.

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Course content

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Day 1​

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​Basic concepts: Why measure roughness?

Factors affecting surface roughness

Roughness, waviness and form

Methods of surface roughness measurement

Skidded and skidless instruments

Sampling vs. evaluation length​

Amplitude roughness parameters: maximum peak-to-valley roughness (Rmax), ten-point average roughness (Rz(ISO)), maximum height of roughness profile (Rz), average roughness (Ra), root-mean-square roughness (Rq), maximum height of peaks (Rp), maximum depth of valley (Rv), skewness (Rsk), kurtosis (Rku)​

Spacing roughness parameters: Mean spacing of profile elements (Rsm), mean spacing of peaks (Rpk)

Hybrid roughness parameters: Root-mean-square profile slope (Rdc)

Functional parameters: Material ratio at given depth (Rmr)

Activity 1: Estimate roughness parameters for given trace

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Day 2

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Definition of roundness​

Measurement of roundness

Least-squares circle method

Maximum inscribing circle method

Minimum circumscribing circle method

Minimum zone reference circle method

Eccentricity, concentricity and run-out

Concept of cylindricity and coaxiality

Activity 2: Estimate roundness error for given trace

 

Course duration: 14 hours

 

Trainer fee: Please contact trainer for quotation

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Maximum number of participants: 15

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