clamp nut (4) loosened and assuming that the shoe bracket gib and the carriage bracket gib are properly adjusted, the tool is brought into position and the nut (4) is tightened. We are now ready to chase taper threads or to finish taper turn, or finish taper bore. When carriage feed is engaged, bed bracket and its connecting rod hold lower taper bar and adjustable swivel bar in a fixed position with relation to bed and work. Movement of carriage slides gibbed shoe (5) along taper bar. With lights cuts, nut (4) need not be tightened, then the pull is on the cross feed screw and nut and the end of the screw telescopes in the cross feed telescopic bush, allowing the slide to move in or out.
With the nut (4) tightened, none of the pull is on the cross feed screw, but on the flat draw bar (6) shown over the cross feed screw, which is connected to the bottom slide. This relieves the cross feed screw of all strain and pull and wear, and insures longer life and retains the original accuracy of the screw. Adjustment of the cut is made by loosening clamping nut (4) and setting tool to proper diameter and, of course, tightening nut again after adjustment is made. Most adjustments of the tool are made by the compound rest. There is no necessity of adjusting clamping nut after taper is set, other than to adjust for depth of cut when using the cross feed screw.
And this may be eliminated by using the compound rest screw. GRINDING ATTACHMENT For internal grinding, small wheels are used on special quills or extensions screwed on the regular spindle. For wheels less than 2" diameter the pulleys should be reversed to give the spindle greater speed. Cover the bed ways with clean cloth or paper to protect them from abrasive dust. Dispose of paper for safety. SAFE GRINDING SPEEDS MICROMETER CARRIAGE STOP The micrometer carriage stop is useful when the operator is obliged to bring the carriage to the same definite position a number of times, or where a series of cuts are desired at accurate decimal dimensions from one another, such as in cutting threads.
The stop is clamped to the front vee of the lathe bed. The design of the clamping surfaces is such that there is no danger of scoring the vee of the bed while using this attachment. A micrometer screw with hardened ends is turned by a large diameter collar. The collar is knurled to provide a finger grip for turning, and is graduated to show the travel of the screw in thousandths of an inch. The carriage is brought up against the end of the stop by hand in actual use. Never run carriage against stop with power feed.
DRAW-IN ATTACHMENT For turning small parts from round finished stock there is no more accurate, rapid and economical method than the use of a draw-in collet chuck, either the tube type as illustrated, or the spindle nose type such as the Sjogren chuck. This attachment in the spindle allows bar stock to pass through the tube and to be gripped in the draw-in collet ready to be machined. When applying the draw- in attachment to the lathe, be sure that the ends of the spindle hole and the outside of the collet closer are clean. Any chips or particles of dirt on these surfaces will destroy the accuracy of the work. Many grinding jobs can be done advantageously in a lathe with this attachment:
hard centers can be re- pointed, cutters and reamers sharpened, and all kinds of straight and taper cylindrical and internal grinding. A few thousandths should be left on the work before grinding. 18 Size of wheel 2" 3" 4" 5" 6" Spindle rpm 9550 6380 4775 3825 3190