This paper presents a STEP AP203-214-based machinable volume identifier (MVI) to identify the finish-cut machinable volume in prismatic parts by deducting the rough-machined part from the final part. The MVI provides an intermediate link between rough and finish machining computer-aided process planning system for automatic generation of process plans while machining prismatic parts. To calculate the machinable volumes of manufacturing features, the MVI utilizes the output of the feature identifier which contains the information about the dimensional details, edge loops, edges, vertices, coordinate points, and location planes of the features. In this research, a total of 234 features have been considered; out of which, 32 are normal and 202 are tapered. To calculate the machinable volumes for these features, generalized methodologies are developed for 17 basic feature types, each having a varying number of specific features. Initially, the pattern strings are generated for the front and back face of the rough-machined feature and final feature. Then, MVI uses the predefined syntactic pattern strings stored in the strings database and checks with the generated strings of the feature to determine the shape of the machinable volume stored in the volumes database. After determining the shape, one relevant methodology or more (for features having combination of more than one taper) are selected from among the 17 "feature type" specific methodologies developed for finish-cut machinable volume identification. In this article, methodology is presented for one basic feature type which covers 14 features and explained through one case study. The final output from this module is stored as a text file with full dimensional details of machinable volumes for later use inside the machining planning module. The proposed MVI can be used in Computer Integrated Manufacturing Industries as an intermediate linker to achieve a robust manufacturing environment.

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.

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