Turning between centers on the g0602

[Bi11Hudson]

Some thoughts, if I may; I am not a machinist, I'm an electronicist that uses a lathe in the course of my work. I can see in my "mind's eye" what I'm trying to describe. It sometimes takes a while to translate a concept into words.

Up front, a driver plate sticks out extends farther than a face plate. Deeper shoulder on the back, I guess. Then there are the centers. A "dead" center (soft) on the headstock and a "live" (hardened) center on the tailstock. The dead center is not hardened to allow truing each time it's inserted in the spindle. My "git by" to this is a punch mark on the face of the spindle and a corresponding mark for the many items that fit there.(MT3) A drive plate is nice, I usually just use the face plate. I have a drive plate, somewhere, but my faceplate is right up front.

The tailstock (hardened) center is ball bearing mounted. It uses inserts. They look more like Jacobs taper than Morse taper. But I've never measured them. Besides the 60* center, there are bullnose and cup centers. A good selection of seldom used tools.

For turning between centers, the center should extend only far enough beyond the spindle to mount the work. Roughly even with the surface of the plate. This alleviating the need for a long pin on the dog. The center is "soft" so it can be trued, it should be trimmed back so it extends only a very little beyond the driver. This allows the dog to be close to the drive plate. A "witness" mark on the center permits it to be replaced easily without re-truing. The same applies when a smaller center is in an adapter. The center should not extend very far.

Most of my work is small. I often use a "ground clamp" for my drive dog, with the setscrew replaced with a capscrew. Since the work is small with light cuts, there's not a great deal of torque involved. The screw is usually fed in from the back of the faceplate to maintain its' original condition. Then there's the coil winding. Sewing machine bobbins mounted on stainless tubing. I find it easier to use a Jacob's chuck on each end. The tailstock end mounted on ball bearings, of course. It seems to grip the tubing without distorting the ends.

For larger work, I do have proper dogs, but often the work is not "circular" but some odd shape too fragile for the faceplate. So I usually "make" whatever will work. The dogs are buried, just like the driver plate.

The original stated problem is just a matter of getting everything adjusted properly. No "special" parts are needed, nothing to buy. Well, maybe a few extra centers, but they needn't be hardened so they will be cheap. The rest is all a matter of setup.

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[benmychree]

On both of my lathes, the 9" Monarch Jr. and the 19" Regal LeBlond, the faceplates and drive plates are flush with the spindle ends, both have threaded spindles; lathes with type L or Camlock spindles, the faceplates and driving plates will have recesses that will likely require longer centers.
For my Monarch, a standard length center is too long for a bent tail dog to enter the slot.

 

[Mitch Alsup]

Me, personally,

I would drill and tap a couple of holes in the drive plate and mount extensions to the drive plate to catch the ear of the dog. #2 from RJSakowski list above.

 

[benmychree]

Me, personally,

I would drill and tap a couple of holes in the drive plate and mount extensions to the drive plate to catch the ear of the dog. #2 from RJSakowski list above.

Yes, it is a good plan to use driving studs, as they and the associated straight tail dogs do not impart nearly as much deflection to the workpiece as bent tail dogs do, another further development of this is the use of double tail dogs and adjustable eccentric driving studs that balance the driving forces to further reduce deflection of the workpiece due to a torque reaction, this was much more common many years ago when much more work was machined between centers than is done in the present day (or era).