This part of 10791 specifies, with reference to ISO 230-1, the geometric tests for machining centres (or numerically controlled milling machines, boring machines, etc., where applicable) with horizontal spindle (i.e. horizontal Z-axis).
This part of ISO 10791 applies to machining centres having basically four numerically controlled axes, of which three are linear (X, Y and Z) up to 2 000 mm in length, and one is rotary (B'), but refers also to supplementary movements, such as those of sliding spindles, rams, or accessory universal heads. Movements other than those mentioned are considered as special features and the relevant tests are not included in this part of ISO10791.
This part of ISO 10791 takes into consideration, in annexes A, B and C, three possible types of accessory universal heads, described as follows:
— annex A: 45° split indexable heads , with mechanical indexing of the different angular positions of the two bodies (e.g. Hirth couplings): the relevant tests (AG1 to AG9) check only the resulting position of the spindle;
— annex B: swivel heads, with two numerically controlled rotary axes perpendicular to each other (tests BG1 to BG7);
— annex C: 45°split continuous heads, similar to the first type but provided with continuous positioning of the two numerically controlled rotary axes: the relevant tests (CG1 to CG7) check all the geometric features (planes and axes) which contribute to the resulting position of the spindle, excluding the positioning accuracy of the two rotary axes; these tests can also be used for a deeper investigation of the 45° indexable heads, if their movements and locks allow this.
This part of ISO 10791 deals only with the verification of geometric accuracy of the machine and does not apply to the testing of the machine operation, which should generally be checked separately. Certain tests concerning the performance of the machine operating under no-load or finishing conditions are included in other parts of ISO 10791.