Southbend SB1231 Operation, To clamp a workpiece in the chuck, Install a center in the tailstock

CAUTION: During the next step, the chuck may come off suddenly, so it is important that you are ready to support its weight with a chuck cradle to prevent crushing your fingers or dropping the chuck.

4.Using a dead blow hammer or other soft mallet, lightly tap around the outer circumference of the chuck body to break the chuck free from the camlocks and the spindle nose taper.

5.Use a rocking motion to carefully remove the chuck from the spindle.

—If the chuck does not immediately come off, rotate the chuck approximately 60˚ and tap again. Make sure all the marks on the cams and spindle are in proper alignment for removal.

Operation

Non-cylindrical parts can be held and brought into the spindle centerline for facing or boring The other benefit is that the majority of workpieces can be positioned out of the spindle rotation axis if a bore (see Figure 9) or a step needs to be cut into a workpiece on an outlying edge. For the best grip possible on odd-shaped workpieces, one or more jaws can also be rotated 180° to grab more surface area for clamping.

If all four jaws cannot be used to hold the workpiece, you must use faceplate to reduce the risk of a workpiece being thrown.

To clamp a workpiece in the chuck:

1.DISCONNECT LATHE FROM POWER!

2.Install a center in the tailstock.

3.Retract each jaw and place the workpiece flat against the chuck face.

4.Slide the tailstock forward, so the tip of the dead center applies enough pressure against the workpiece to hold it in place, and then lock the tailstock in position.

5.Move each jaw until it makes light contact with the workpiece.

6.Following the sequence shown in Figure 8, tighten each jaw in small increments to move the workpiece into the required position. Check frequently to make sure the intended center point of the workpiece has not wandered away from the spindle centerline while the jaws are being tightened.

workpiece

2

4

Figure 8. Tightening sequence.

7.After the workpiece is held in place by the jaws, turn the chuck by hand and pay attention to the workpiece alignment.

—If the workpiece is not correctly aligned for your operation, turn the chuck and make fine adjustments by slightly loosening one jaw and tightening the opposing jaw until the workpiece is correctly aligned (see Figure 9 for an example).

Figure 9. Non-concentric workpiece correctly clamped

in the 4-jaw chuck.