DML Test 2 Advanced Lathe Operations Questions And Answers 2022/2023

you have a rectangular workpiece that needs a facing operation plus center drilling, and a universal chuck is mounted on the lathe spindle. What is your procedure to prepare for machining? - Answer - a lathe board is placed on the ways under the chuck, and the chuck removed, because it is the wrong chuck to hold rectangular work. The mating parts of an independent chuck and the lathe spindle are cleaned and the chuck is mounted. The part is rouchly centered in the jaws and adjusted to center by using the back of a tool holder or a dial indicator Should the point of the tool be set above, below, or at the center of the spindle axis when taking a facing cut? - Answer - center If you set the quick-change gearbox to .012 in, is that considered a roughing feed for facing? - Answer - no, the resultant facing feed would be approximately .003 to .005 in which would be a finishing feed An alignment step must be machined on a cover plate .125 in, +- .003 in, in depth. What procedure should be taken to face to this depth? how can you check your final finish cut? - Answer - the compound must be swung to either 30 or 90 degrees so that the tool can be fed into the face of the work by a measured amount. A depth micrometer or a micrometer caliper can be used to check the trial finish cut What tool is used for facing shaft ends when they are mounted between centers? In what way is this tool different from a turning tool? - Answer - A right-hand facing tool is used for shaft ends. It is different from a turning tool in that its point is only a 58-degree included angle to fit in the narrow space between the shaft face and the center If the cutting speed of aluminum is 300 sfpm and the workpiece diameter is 4 in, what is the rpm? the formula is rpm = (4(CS))/D - Answer - (4(300))/4 = 300rpm Give two reasons for center drilling a workpiece in a lathe - Answer - prepare work for turning between centers, spotting workpieces for drilling in the lathe name two causes of center-drill breakage - Answer - feeding the drill too fast and having the lathe speed too slow, off center tailstock, off center workpiece in a steady rest, lack of cutting oil What happens when you drill too deeply with a center drill? - Answer - the sharp edge provides a poor bearing surface and soon wears out of round, causing machining problems such as chatter What is the drill point diameter of a number 5 center drill? - Answer - 3/16 in Give two advantages and disadvantages of turning between centers - Answer - no loss of concentricity, removed from the chuck and returned without loss of synchronization between the thread and tool; cutting off between centers is not done because it would break the parting tool and ruin the work, steady rest work is not done with work mounted in a center in the headstock spindle What other method besides turning between centers is extensively used for turning shafts and long workpieces supported by the tailstock center? - Answer - workpiece is held in a chuck on one end and in the tailstock center on the other end What factors tend to promote or increase chip curl so that safer chips are formed? - Answer - coarser feeds, deeper cuts, smaller rake angles, chip breakers