The CNC lathe is one of the most versatile and common pieces of equipment used in manufacturing. The operations done on a CNC lathe are facing, turning, taper turning, thread cutting and knurling. In the last article, we explained different parts and types CNC lathe machines, today we are going to be discussing each of these CNC lathe machine operations.
For any CNC machining operation, the workpiece should be held firmly and centered. The devices used for this purpose are chuck and center turning.
Turning is the operation of producing a cylindrical surface by advancing the tip of the tool by a distance perpendicular to the axis of work and then moving the tool parallel to the axis of rotation of the workpiece. This distance is called the depth of cut, often a facing operation is done before a turning operation, in facing the two is smooth at the end of the work perpendicular to the axis of work while it is rotating. This is a cutting motion and as a result a flat surface is produced at the end of the workpiece, the general procedure for turning is as follows. Workpiece is held in a chuck with a short length projecting out and then it is rotated facing.
Facing is done by moving cutting tool known as the facing tool. Across the end face of the workpiece, a center hole is produced on end of the workpiece, using a drill bit fixed on the tailstock, the workpiece is partially pulled out from the chuck and the required length is exposed. Tailstock dead center is pushed onto the hole drill at the end of the workpiece, now both ends of the burpies are centered and supported. The workpiece is rotated and turning operation is done using a turning tool until the required diameter is obtained.
3. Taper Turning & Knurling
Taper turning is CNC lathe operation of producing a conical surface on the workpiece, it can be done in multiple ways. First one is the forming method. We use a tool of straight edge with its width larger than the required length of paper, we keep the tool edge angle which is half the paper angle and three perpendicular to the lathe axis. The second one is a tailstock set our method. We ship the axis of rotation of workpiece by half the paper angle, this is done by moving the tail stock a certain distance perpendicular to the lathe axis, then the tool is Fredd parallel to the late axis and this method is used for producing small tapers on long jobs. Third one is a compound rest method. The compound rest on the closed slide is sold by half the taper angle, now the free given to the compound rest is not parallel, but at a desired angle to the lathe axis there are angle markings on the base of the compound rest. So any decide angles of paper is possible. But the distance the compound rest can move is limited, so taper length is much shorter than the tailstock set over method. Nearly it is the operation of producing a rough diamond like pattern on the workpiece, it is done using a knurling tool having the same diamond pattern. The tool is pressed on the cylindrical surface of the rotating tool along with that totally smooth along the length of the work piece.