Originally Posted by
Toolguy
That may be a 7 Morse taper. You can look up the specs in Machinery's Handbook. If you find the spindle is worn or not at the correct angle, you can recut it with a carbide insert boring bar. You can use the taper attachment, or swing the compound slide around to the correct angle. I like to use the compound for short angles.
Once you determine what the taper should be (the model G0749 is a #7MT) You can easily set the compound slide to the desired taper like this:
1- Put a bar in the chuck or collet and turn to get a full cleanup on the material diameter with a good finish. Diameter must be the same for the length of the turned part. Keep part in place until angle is set.
2- Calculate a right triangle for one side of the taper. Set up a dial indicator perpendicular to the turned part, on the side facing the operator. The compound slide is the hypotenuse, indicator stem is the short side and the part is the long side.
3- Adjust the angle of the compound until the dial indicator reads the number of the short side when the compound is dialed the length of the long side. Tighten compound slide in place.
4- Remove indicator and bar, add part to be turned and cutting tool, and cut taper. In this case, the part to be turned would be the spindle taper. No need for a toolpost grinder, just go over the surface several times with the carbide insert. Make sure the toolpost is tight, so it doesn't move during the cutting process.