Dead-Center with no taper?

[middle.road]

I would like to have a dead-center I can put into my 3-jaw chuck... But seems every one I look at has a taper only. Is there any with no taper that are common? Or perhaps a sleave to un-taper a dead-center?

I know i could probably just turn a piece and add a point myself easy enough, but I would like a professional made dead-center I can put in my chuck. Maybe there is a specific name for these and why I am looking in the wrong place?

like this golden oldie? I use it for exactly that.

Just had a thought, mount a full taper type, fire up the Dumore TPG and grind a straight-flat on it.
I have no idea how long that would take though with the amount of material that has to be removed.

 

[Dave Paine]

For the original post asking about how to mount a Morse Taper in a chuck, you can purchase sockets or sleeves which are parallel on the outside and a Morse Taper in the inside. Some sites call them sockets, some call them sleeves.

An example link

Hard sockets at Victor Machinery

 

[The_Apprentice]

Thanks Dave, exactly what I was looking for.

 

[higgite]

There are a few situations that come to mind. One I was thinking about, was if I am going to polish an item, I would like to have a dead center in a chuck, and a live center on the other side so I am free to use emorycloth on the whole item without risking it getting scuffed up by jaws or anything else. I also happened to see someone else doing just this while polishing aluminum on their lathe, so it seems I am correct in my idea on this approach?

I've never done it so I'm asking, is there typically enough friction between the dead center and the work piece to spin it against the friction of the emery cloth without using a dog?

Tom

 

[The_Apprentice]

 

[projectnut]

Woah! Isn't that machine ancient? I always wondered if that company really was located in Seneca Falls New York, because I live close there and have driven through many times. I think it's cool that there MAY have been a lathe factory there at some time. Too bad times have changed and US companies outsource their jobs over-seas to save a buck.

My Seneca Falls machine is a Star model #20K. It has a 10"x48" capacity (actually sold as a 9"x60" machine) that was built in 1916 in Seneca Falls New York. It was the machine my wife's grandfather used for over 40 years when he worked fin the prototype shop for a vending machine manufacturer. When he retired in the early 1950's the machine was given to him as a retirement present. It's been in the family since then. It went to my father in law in the early 1970's, and I acquired it in the late 1990's. It still gets used on an almost daily basis.

It was my go to machine until last year when I purchased a Sheldon 13"x56" machine (1960's era). The Sheldon now does more of the heavy work while the Seneca Falls machine still excels at the smaller stuff. The age of the machinery in my shop ranges from the early 1900's to the late 1980's. About half of them are older than I am. Fortunately they are also in better shape. I would expect all of them to be productive long after I'm gone.

There are a number of Seneca Falls machine catalogs at the Vintage Machinery.org website:
http://vintagemachinery.org/mfgindex/detail.aspx?id=734&tab=3

Most of them have a graphic of the factory on either the front or rear cover.

 

[petertha]

I would think for something like the video, just mount a dedicated cylindrical 60-deg point in the chuck (or collet or whatever) & re-dress the cone prior to a polishing session. You could make it from 0.5" dia tool steel as an example. Turning it in-situ will ensure its running concentrically about as accurately as can be expected. The thing is, even if you found a ground & hardened cylindrical dead center accurate to 0.0000001", if that was mounted in a 3J chuck with 0.002", then that dictates how your center will run.

Also, note that this is hand polishing, not turning. He may well might be taking 2-5 thou off with the paper/coarse pad before it gets to the finishing & shine stage depending on how it was turned (or not) beforehand. This is called polished potato syndrome. Its shiny all right, but whether it fits another part or meets a certain dimension is another matter. He is basically using the centers to get at the full surface as opposed to an end held in a chuck.

But getting back to the cylindrical (non-tapered) shank dead center, actually I was looking for a 'tool' with 0.5" shank, accurately ground & ideally hardened like a regular dead center. As you fond, 99.9% dead centers seem to be taper shank. I want to put this in a boring head used in a tailstock (offset taper) installation. I've pretty much resigned to making my own from tool steel & either run it unhardened or maybe just the very tip to minimize distortion & need for dress grinding. So that would be an example of where its 'made' may not end up being where its ultimately used, so accuracy counts on the initial making.

 

[umahunter]

I have one about 10 inches long I made out of 1 inch drill rod cut the taper I made it 10 inches so everytime I use it I can take a skim cut to make it concentric and won't have to replace it for awhile

 

[petertha]

Exactly. Just like sharpening a wood pencil when the lead gets dull. At say 0.010" skim per re-dressing, you have less than 1000 sharpens before its a nub. LOL

 

[Tozguy]

Is this just to prevent you from removing the chuck? I mean, I am confused as to why you would want a center for a chuck.

As an example:
Recently had to true up a shaft that had been turned in a four jaw. With a center in the 4 jaw, it was adjusted to remove run out on the surface closest to the chuck. The center was turned from a piece of old McPherson strut with a circlip to prevent the center from slipping into the chuck (long story here ).
The choice of steel is not critical since the work does not turn on a headstock center.