Development of Precision Polishing Machine Based on Parallel-Kinematic System

Zavid Mohamed, Liam Blunt, Christian Young, Zhen Tong, Duo Li

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Increasing demand on mass production of high precision functional surfaces (curved or freeform) has pushed the development of relatively low cost and high precision surface finishing processes for mould manufacturing. For some applications such as small optical lenses, the existing bonnet polishing (BP) process has limitation in polishing the inner surfaces of moulds due to tool head size and generation of mid-spatial frequency errors. In this paper, a novel precision polishing machine suitable for polishing inner surface of mould was developed based on a parallel-kinematic precision positioning system (PI Hexapod H840.D2). The hexapod was held in a machine frame, which allows precision movement in 6 degrees of freedom. An air bearing, electrically driven spindle (speed range from 500 rpm to 8000 rpm) was mounted to the Hexapod to drive the polishing tool. A rubber bonnet tool with a polyurethane pad was used to engage the part surface. In order to test the performance of this prototype machine, the machine was used to polish flat surfaces of P20 steel alloy which is widely used to manufacture plastic injection moulds. All polishing processes were carried out using diamond paste with particle size of 3 μm. Pre-polishing results showed that the feed rate of the hexapod, spindle rotating speed, tool offset and number of polishing passes are the main factors affecting the polished surface quality. A Taguchi approach was used to study the influence of these four main polishing parameters on the machined surface. After optimisation of the processing parameters, the polishing machine can consistently achieve ≤ 10 nm surface roughness Ra.

Original languageEnglish
Title of host publicationProceedings of the 17th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2017
Publishereuspen
Pages273-274
Number of pages2
ISBN (Electronic)9780995775107
Publication statusPublished - 1 Jan 2017
Event17th International Conference of the European Society for Precision Engineering and Nanotechnology - Hannover Congress Centre, Hannover, Germany
Duration: 29 May 20172 Jun 2017
Conference number: 17
http://www.euspen.eu/events/17th-international-conference-exhibition/ (Link to Conference Website )

Conference

Conference17th International Conference of the European Society for Precision Engineering and Nanotechnology
Abbreviated titleEUSPEN 2017
CountryGermany
CityHannover
Period29/05/172/06/17
Internet address

Fingerprint

Polishing machines
Polishing
polishing
Kinematics
kinematics
spindles
Bearings (structural)
Industrial Oils
Diamond
Polyurethanes
surface finishing
Rubber
Alloy steel
Ointments
gas bearings
curved surfaces
Surface properties
Lenses
Diamonds
rubber

Cite this

Mohamed, Z., Blunt, L., Young, C., Tong, Z., & Li, D. (2017). Development of Precision Polishing Machine Based on Parallel-Kinematic System. In Proceedings of the 17th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2017 (pp. 273-274). euspen.
Mohamed, Zavid ; Blunt, Liam ; Young, Christian ; Tong, Zhen ; Li, Duo. / Development of Precision Polishing Machine Based on Parallel-Kinematic System. Proceedings of the 17th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2017. euspen, 2017. pp. 273-274
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abstract = "Increasing demand on mass production of high precision functional surfaces (curved or freeform) has pushed the development of relatively low cost and high precision surface finishing processes for mould manufacturing. For some applications such as small optical lenses, the existing bonnet polishing (BP) process has limitation in polishing the inner surfaces of moulds due to tool head size and generation of mid-spatial frequency errors. In this paper, a novel precision polishing machine suitable for polishing inner surface of mould was developed based on a parallel-kinematic precision positioning system (PI Hexapod H840.D2). The hexapod was held in a machine frame, which allows precision movement in 6 degrees of freedom. An air bearing, electrically driven spindle (speed range from 500 rpm to 8000 rpm) was mounted to the Hexapod to drive the polishing tool. A rubber bonnet tool with a polyurethane pad was used to engage the part surface. In order to test the performance of this prototype machine, the machine was used to polish flat surfaces of P20 steel alloy which is widely used to manufacture plastic injection moulds. All polishing processes were carried out using diamond paste with particle size of 3 μm. Pre-polishing results showed that the feed rate of the hexapod, spindle rotating speed, tool offset and number of polishing passes are the main factors affecting the polished surface quality. A Taguchi approach was used to study the influence of these four main polishing parameters on the machined surface. After optimisation of the processing parameters, the polishing machine can consistently achieve ≤ 10 nm surface roughness Ra.",
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Mohamed, Z, Blunt, L, Young, C, Tong, Z & Li, D 2017, Development of Precision Polishing Machine Based on Parallel-Kinematic System. in Proceedings of the 17th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2017. euspen, pp. 273-274, 17th International Conference of the European Society for Precision Engineering and Nanotechnology, Hannover, Germany, 29/05/17.

Development of Precision Polishing Machine Based on Parallel-Kinematic System. / Mohamed, Zavid; Blunt, Liam; Young, Christian; Tong, Zhen; Li, Duo.

Proceedings of the 17th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2017. euspen, 2017. p. 273-274.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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AU - Blunt, Liam

AU - Young, Christian

AU - Tong, Zhen

AU - Li, Duo

PY - 2017/1/1

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N2 - Increasing demand on mass production of high precision functional surfaces (curved or freeform) has pushed the development of relatively low cost and high precision surface finishing processes for mould manufacturing. For some applications such as small optical lenses, the existing bonnet polishing (BP) process has limitation in polishing the inner surfaces of moulds due to tool head size and generation of mid-spatial frequency errors. In this paper, a novel precision polishing machine suitable for polishing inner surface of mould was developed based on a parallel-kinematic precision positioning system (PI Hexapod H840.D2). The hexapod was held in a machine frame, which allows precision movement in 6 degrees of freedom. An air bearing, electrically driven spindle (speed range from 500 rpm to 8000 rpm) was mounted to the Hexapod to drive the polishing tool. A rubber bonnet tool with a polyurethane pad was used to engage the part surface. In order to test the performance of this prototype machine, the machine was used to polish flat surfaces of P20 steel alloy which is widely used to manufacture plastic injection moulds. All polishing processes were carried out using diamond paste with particle size of 3 μm. Pre-polishing results showed that the feed rate of the hexapod, spindle rotating speed, tool offset and number of polishing passes are the main factors affecting the polished surface quality. A Taguchi approach was used to study the influence of these four main polishing parameters on the machined surface. After optimisation of the processing parameters, the polishing machine can consistently achieve ≤ 10 nm surface roughness Ra.

AB - Increasing demand on mass production of high precision functional surfaces (curved or freeform) has pushed the development of relatively low cost and high precision surface finishing processes for mould manufacturing. For some applications such as small optical lenses, the existing bonnet polishing (BP) process has limitation in polishing the inner surfaces of moulds due to tool head size and generation of mid-spatial frequency errors. In this paper, a novel precision polishing machine suitable for polishing inner surface of mould was developed based on a parallel-kinematic precision positioning system (PI Hexapod H840.D2). The hexapod was held in a machine frame, which allows precision movement in 6 degrees of freedom. An air bearing, electrically driven spindle (speed range from 500 rpm to 8000 rpm) was mounted to the Hexapod to drive the polishing tool. A rubber bonnet tool with a polyurethane pad was used to engage the part surface. In order to test the performance of this prototype machine, the machine was used to polish flat surfaces of P20 steel alloy which is widely used to manufacture plastic injection moulds. All polishing processes were carried out using diamond paste with particle size of 3 μm. Pre-polishing results showed that the feed rate of the hexapod, spindle rotating speed, tool offset and number of polishing passes are the main factors affecting the polished surface quality. A Taguchi approach was used to study the influence of these four main polishing parameters on the machined surface. After optimisation of the processing parameters, the polishing machine can consistently achieve ≤ 10 nm surface roughness Ra.

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KW - Taguchi approach

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M3 - Conference contribution

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EP - 274

BT - Proceedings of the 17th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2017

PB - euspen

ER -

Mohamed Z, Blunt L, Young C, Tong Z, Li D. Development of Precision Polishing Machine Based on Parallel-Kinematic System. In Proceedings of the 17th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2017. euspen. 2017. p. 273-274