Toolpath algorithm for free form irregular contoured walls/surfaces with internal deflecting connections

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2 Citations (Scopus)


This paper presents a toolpath generation method to efficiently machine free form irregular contoured walls/surfaces (FIWS) containing internal deflecting connections (IDC's). The toolpath generation method is based on a series of identifications and calculations, where initially a 'Main Computable Zone (MCZ)' in the Machinable Areas (Ma's) of FIWS is identified based on the Tool track dimensions (Td). Then the MCZ's are divided into Split Computable Zones (SCZ's) and Split Computable Zones for Internal Connections (SCZI's) which are subsequently sub divided as 'Categorized Computable Zones' (CCZ) with simple-medium-high complexity. The identification of CCZ's is based on the 10 different types of FIWS representations developed for this study. From the CCZ's categorization of complexity, they are further split into smaller 'Machinable Zones (MZ's)' using a 4-step algorithm. In the algorithm, the first step calculates a common plane (CP) to cut the steep areas in the CCZ's where the tool cannot have full access for machining. Once the CP is identified, the second step is to extend it by moving them along the CCZ's and calculate the necessary 'Machinable Zones (MZ's)' in the next stage. This is done by finding the intersection of CP with the FIWS through a point to point/line plane intersection concept. After this step, the MZ's are re-iterated by including the open and closed surface criteria and is analyzed for the IDC's to be combined in the fourth stage. This is achieved by adding up the IDC's with the existing MZ's computed by the algorithm. At every stage, the algorithm considers tool collision avoidance and tool rubbing in the CCZ's and MZ's. This is by an automatic computation based on the height to fixture clearance for safer neck length which avoids collision and rubbings in the final toolpaths. Finally, a combined tool path is generated for all the MZ's and has been verified/tested for a sample part and impeller containing similar shapes using UG NX/STEP-NC software

Original languageEnglish
Pages (from-to)3037-3047
Number of pages11
JournalMaterials Today: Proceedings
Issue number4
Publication statusE-pub ahead of print - 4 May 2020
Externally publishedYes
Event2nd International Conference on Materials Manufacturing and Modelling, ICMMM 2019 - Vellore, India
Duration: 29 Mar 201931 Mar 2019

Bibliographical note

Funding Information:
The author gratefully acknowledges DST Government of India, for the support to the research on 5 Axis STEP-NC (AP-238) Machining of Free Form / Irregular Contoured Surfaces based on which the present article is contributed.

Publisher Copyright:
© 2019 Elsevier Ltd.


  • CCZ
  • MCZ
  • SCZ
  • toolpath

ASJC Scopus subject areas

  • Materials Science(all)


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