One liners

[mklotz]

I think I understand them all well enough. The drive dog I had to think about a little. Are you holding a centre in the chuck and then clamping the ground clamp onto the object you wish to drive?

Yes, exactly. With the work held between centers, there are a number of ways to drive the work. Most "dogs" consist of something that clamps to the work; drive force can come from a pin projecting from a face plate mounted behind the center. Sometimes the pin is integral to the dog and fits into a slot in the face plate.

When I need to work between centers I like to have the 3jaw mounted. A piece of steel clamped in the chuck is turned to a 60 degree point. This approach guarantees that the center is perfectly aligned with the rotation axis of the lathe spindle. If the stock I'm turning permits, the chuck end of the stock is drilled to accept a Loctited pin that is driven by the chuck jaws. With no projecting dog bits spinning about this approach is much safer than the conventional dog. Of course, if that technique isn't possible, I use the dog shown in the picture.