Atlas 10 questions regarding chuck and runout

On the subject of headstock or spindle chucks,they have probably been discontinued as Jacobs has been reported as having moved all of their manufacturing to China. But at one time, they made four different models.

Model..Spindle Thread........Capacity
55B...........1"-8.............................0-17/32"....(1/8"-5/8" Special Order)
56B...........1"-10...........................0-17/32"....(1/8"-5/8" Special Order)
58B...........1-1/2"-8....................1/8"-5/8"
59B...........1-1/2"-8....................3/16"-3/4"
 
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Can anyone elaborate on the usefulness of headstock chucks? The 1955 Popular Mechanics Do-It-Yourself Encyclopedia talks about adapting a drill chuck with a draw tube and hand wheel-as a sort of poor man's collet chuck. In this case the drill chuck is held in a 4 jaw chuck and dialed in to minimize run out.

In "How to run a Lathe" headstock chucks are also mentioned as a collet chuck analog, the text states runout can be as low as 2 thou.

I picked up two of the Jacobs 55B headstock chucks affixed to shafts passing through pillow blocks with 4 step pulleys in the middle at a yard sale up the street from me a few years ago. I thoughtlessly neglected to ask the old gent (I'm 65 so old to me is, well, getting up there) selling these what he used them for. They are threaded 1"-8 so not immediately useful on my Atlas lathes. I did procure an adapter meant, I think, for woodworking lathes and played with it. Run out was pretty abysmal as I recall. Plus the adapter is solid so you lose the ability to pass stock through.

While I do have a partial set of 3AT collets I have lots of gaps. Maybe securing a headstock chuck in a 4 jaw with a made up draw tube has legs for those odd sizes.

Tim
 
The 1"-8 threads fit the spindle of the 101.07301, the 6" lathe version that Atlas built for Sears from 1939 until 1957. I am told that some wood lathes at the time had the same spindle thread and sears already carried some accessories in that thread.

Your best bet is to sell or trade them to someone with a 101.07301.

They are quite handy for handling small parts and in that service are a little safer than a larger 3- or 4-jaw lathe-style chuck. because when spinning there is very little danger of snagging clothing or fingers on them. They can also hold milling cutters but I wouldn't recommend doing that other than as a temporary expedient as the shanks of milling cutters are normally hardened as are the chuck jaws so the grip isn't as reliable as that of a collet. However, they would normally be cheaper than a collet chuck or draw tube and a set of collets.
 
Robert, you mentioned the ER collet chucks this seems to be a reasonable option for me but the 1-1/2 x 8" threaded model seems to be hard to find so far. You also mentioned using a draw bar with the ER chuck, can you explain this a little more? Is it unsafe to use the ER chuck without this option? I am not sure of the limitations with the ER collets, here is a image of the type of work I want to do on the lathe with a collet system that will allow this. The pictures are of ferrules, which are the German Silver or Duronze connections for a bamboo fly rod. DSCN1637.JPG
 
@oldschoolcane,

First, please set up your signature. Click on your UserID in the main tool bar at TOS and then click on Signature in the list that comes up. You can also add your brag list of equipment that you own but that isn't required. I think that there is a limit to the number of lines that you can add depending upon donor status but if so, everyone gets at least one line.

The reason for using a draw bar with any 3MT arbor in the spindle is that if you don't, sooner or later you are going to have the arbor come loose and ruin something. Milling cutters, for example, pull on the cutter when cutting and sooner or later will pull the arbor loose. The only exception that I know of is MT shank drill bits which (almost??) always come with the tang type MT end.

The other practical disadvantage of MT arbors on ER collet chucks with or without a draw bar is that you will have to pre-cut the pieces for the ferrules to be made from instead of running a long piece of stock through the spindle. And the right-end operations on the long pieces will probably require use of some sort of live center to support the ferrule while machining on that end instead of always keeping the working position near the collet.
 
On tapers: A drawbar should be used on any tapered collet chuck. I use an Atlas MF-C benchtop mill with a MT-2 drive. Also have a vertical mill with R-8 collets. Both of these have drawbars. I (hand) drilled the back of my MT-3 to ER-25 collet holder. It currently is a 3/8-16 all thread drawbar. I do plan to increase the size so I can use a hollow tube for long work pieces. But that's for the undefined future. It needs to be done, but I have other priorities as well.

As you are finding out chasing your chuck problems, congrats by the way on finding another, there are many gizmos and contraptions to fit lathes. One of the reasons for using an "old iron" U.S. made machine. A stand alone "everything" machine. The number of attachments will be anything you can dream up, plus 2 or 3. I make a number of custom solenoids, winding coils, and have a couple of unusual gears in the threading train to follow wire sizes. And another gizmo to count turns of the spindle. Then there is a milling attachment that doesn't get used much since I acquired the MF-C.

The point being that for your purposes a large size chuck can be used for a "poor man's" collet. It doesn't have to be 1-1/2-8 thread to go on the spindle nose. Get the largest threaded chuck you can find. 5/8 comes to mind. . . Take a piece of 5/8 rod and thread the end to fit the chuck. Then drill (& ream?) to 1/2 or so the full length, 3 inches~. Fasten on the drill chuck and mount in the 3 jaw. That would get you going until you learn more about the machine. If runout is a problem, find the lowest point and mark it on the mandrel and the chuck so it can be replaced as needed.

BTW, I don't use the signature line because I'm paranoid. . .
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I didn't manage to comment on one of Bill's earlier comments in time to have my comment follow his so this isn't even on the same page (and this forum doesn't allow for insertion of comments out of chronological order even for Moderators). But on the subject of the jaws that may be found on 3-jaw chucks, there were actually three types, one quite uncommon. The most common type have the truncated threads on the back curved, the jaws will only mesh with the scroll one way, and two sets of three jaws are always furnished with the chuck when new, Unfortunately, the second set of jaws is, more often than not, lost by the time that the chuck gets re-sold as used.

The second type, usually found on more expensive chucks, have three master jaws matched to the scroll and removable reversible outer jaws machined to tighter tolerances. In most cases you can buy replacement outer jaws if the originals get worn or damaged. And you can buy what are usually called "soft jaws" for the chuck and machine them for special purposes.

The third type that Bill referred to are quite rare but the truncated threads on the rear of each jaw are lozenge shaped instead of curved and will fit into the scroll in either direction. However, these are more expensive to make than the standard solid jaws and because one side of the truncated threads are only in line instead of area contact with the scroll, neither the jaws nor the scroll last very long compared to standard jaws. I wouldn't personally buy one of them other than as a curio. I'm not certain that anyone still makes this type of chuck.

On a different subject, the term "drill chuck" is more commonly taken to mean the type of keyed or key-less 3-jaw chucks as are typically found on electric drills (sometimes called "drill motors") and drill presses. I wasn't aware that the term once had a different meaning.
 
wa5cab said:
On a different subject, the term "drill chuck" is more commonly taken to mean the type of keyed or key-less 3-jaw chucks as are typically found on electric drills (sometimes called "drill motors") and drill presses. I wasn't aware that the term once had a different meaning.
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I have an uncle, Pop's older brother, that was the engineer that commissioned the Pentagon building way back when. I now am in possession of some of the textbooks he used for study to become that engineer. In those books, a lathe chuck was defined, in the 1920s, of two different styles. A "drill" chuck being the inside gripping jaws that are frequently also used for small work. A "lathe" chuck is defined as outside gripping jaws, such as used for large work. The designation is archaic, granted, but quite applicable when describing chuck jaws.

I am well aware of the current usage of terms relating to machine parts. And when dealing with a beginner, I can be somewhat confusing in my choice of terminology. Most of what I learned was from old books. Archaic books. . . I was a marine electrician since 1969, my only learning of machine work from a tutor was in 1969-1971 from a shipboard machinist whose shop was next to mine. The rest came from old books. I couldn't pay the price for modern textbooks, I had to read what I could find on my own on the subject of machining.

Sorry for the rant, I was set off at a weak moment. . .

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I never have really liked the terms "inside" and "outside", given that both sets of jaws will grip on both the inside and the outside of a suitable work piece. The only way that I can keep the terms straight is to think about which section of the three on each jaw is the tallest. But I also don;t like calling the "inside" jaws drill chuck because that;s what everyone for at least the last 80 years has called most Jacobs style chucks. No way to be happy, I guess!
 
If I wasn't so darned archaic myself, I probably would have used different terminology. Since I didn't learn by an acceptable method, I tend to use a word that is descriptive rather than what is proper, or acceptable. The language (English) is very fluid with adaptations from many languages. I don't have a lot of formal schooling and what I learned at home was from a very old school family. Most everything was learned from books. The Dr Dolittle series was my "primer". I could preach for hours, denigrating myself, but that so easily devolves into political statements that I deem it better to just bow out.

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