Chapter 3 Datums 121 16. Name the three datums of a complete datum reference frame. ________________ _______________________________________________________________________ _______________________________________________________________________ _______________________________________________________________________ 17. When referring to the datum reference frame in the feature control frame, the ____________ datum is given fi rst followed by the ____________ and ____________ datums. This is known as the datum ____________. 18. Defi ne degrees of freedom. _______________________________________________ _______________________________________________________________________ _______________________________________________________________________ 19. Identify how many degrees of freedom are found on every part, and identify how many are translational and how many are rotational. ____________________ _______________________________________________________________________ _______________________________________________________________________ 20. Defi ne translational. _____________________________________________________ _______________________________________________________________________ _______________________________________________________________________ 21. Defi ne rotational. _______________________________________________________ _______________________________________________________________________ _______________________________________________________________________ 22. Defi ne datum targets.____________________________________________________ _______________________________________________________________________ _______________________________________________________________________ 23. The primary datum plane must be established by at least ______ point(s) on the primary datum surface. 24. The secondary datum plane must be established by at least ______ point(s) on the secondary datum surface. 25. The tertiary datum plane must be established by at least ______ point(s) on the tertiary datum surface. 26. How is a datum target area represented on a drawing? _______________________ _______________________________________________________________________ _______________________________________________________________________ _______________________________________________________________________ 27. The circular datum target area is dimensioned with ____________ dimensions or ____________ dimensions to locate the ____________ from datums and the diameter of the area is provided in the ____________ half of the datum target symbol.