Assessments - 4, GPA: 3.8
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Facilidade de uso
The internal jaw can hold a workpiece on the inside or outside surface of the jaw (exterior or interior of the part). The external jaw holds the part from the inside surface of the jaw (exterior of the part). Common uses are shown in Figure 14. Figure 13. Internal & external jaws. Internal Jaw External Jaw External Jaw Internal Jaw with Internal Grip Internal Jaw with External Grip Figure 14. Workholding options. replacing chuck Jaws Changing jaws on the 3-jaw chuck is straight forward, but attention must be paid to the sequence in which the jaws are loaded into the chuck. To replace the jaws: 1. unplug thE lathE! 2. remove all of the jaws on the chuck by turning the chuck key counterclockwise. 3. Examine the inside of each slot in the chuck for debris and clean. 4. Each jaw will be numbered 1,2,3 or a,B,C. numbers can be found in the slot, at the bottom of each jaw. 5. locate jaw #1. 6. insert the chuck key into the chuck. 7. turn the chuck key clockwise while looking straight into the face of the chuck. notice the beginning of the lead thread on the scroll come into view through the slot in a counterclockwise direction (see figure 15). 8. insert jaw # 1 into this slot then continue to turn until the jaw is engaged with the lead thread. 9. repeat these steps for Jaw #2 then Jaw #3. it is important to follow these points when replacing jaws in your 3-jaw chuck: • the jaws must be loaded in sequence beginning with the #1 jaw. • the chuck, scroll, and jaws should be thoroughly cleaned before assembly. (a paint brush works great for cleaning the scroll). • never use a combination of inside and outside jaws to hold a workpiece. • do not over-tighten the chuck jaws. damage will occur, resulting in loss of accuracy. • do not load the jaws into chuck incorrectly to do eccentric work. use a 4-jaw chuck for this purpose. • 3-jaw chucks will always have a little run-out. it is advisable to measure the run-out of a workpiece after it is mounted in the chuck. if a higher degree of accuracy is desired, replace the 3-jaw chuck with a 4-jaw chuck and adjust the workpiece while using a dial indicator until the desired concentricity is achieved. figure 15. lead thread. -19 Model g8688 (Mfg. 3/09+) removing/Installing chuck or faceplate the Model g8688 chuck is mounted directly to the spindle nose plate by the use of studs and hex nuts. To remove a chuck or faceplate from the lathe spindle: 1. unplug thE lathE! 2. place a piece of plywood over the bedways to protect your hands and the precision ground bedways in case the chuck should fall. pINcH HAzArD! protect your hands and precision ground bedways with plywood when removing lathe chuck! The heavy weight of a falling chuck can cause serious injury. 3. hold the chuck/faceplate with your hand or a chuck key, and use a 10mm wrench, to loosen and remove the three chuck mounting hex nuts on the back of the spindle nose plate. 4. remove the chuck/faceplate from the spindle nose by pulling it out. Note: You may need to tap the chuck/faceplate with a rubber mallet to brake it free of its seal. To install the chuck or faceplate: 1. remove the studs from the chuck or faceplate you just removed, and screw them into the chuck or faceplate you want to install. 2. Measure the stud protrusion, and make sure that the studs extend at least 1.2" from the chuck or faceplate (see figure 16). 1/2" figure 16. installing studs. 3. line up the studs with the holes on the spindle nose and secure the chuck/faceplate with the hex nuts (see figure 17). figure 17. installing the faceplate. -20 Model g8688 (Mfg. 3/09+) Tailstock the tailstock may be moved along the bedway to any desired position and locked in position by a hex nut at its base. the tailstock quill is a Mt#2 taper and will hold tools that match that taper, such as dead center (included), live centers, drill chucks with arbors, and drill bits with tapers. Familiarize yourself with the tailstock components shown in figure 18. A. Quill Lock: locks the quill in position. b. Tailstock Handwheel: Moves the quill in and out of the tailstock. c. Tailstock Lock Nut: locks the tailstock in position to the lathe bed. D. Offset setscrew: helps maintain tailstock position during tailstock offset adjustment. E. Quill: holds tapered tools. f. Offset cap screw: loosening allows tailstock offset to be adjusted right or left of center. G. Quill Gib screw: removes play from tailstock quill. figure 18. tailstock controls. d E F g a B C Tailstock positioning Longitudinal positioning To adjust the tailstock longitudinally: 1. using a 17mm wrench, loosen the tailstock lock nut shown in figure 18. 2. Slide the tailstock into position along the bed, then tighten the clamp nut to secure the tailstock in the new position. Offset positioning Changing the tailstock offset is a common method for turning tapers. the offset cap screw is located under the tailstock and the tailstock must be removed from the bed for this adjustment. therefore, precision tolerances for th...