# Atlas 10 questions regarding chuck and runout



## oldschoolcane (Mar 7, 2021)

I have progressed to the point of trying to do some projects on my reconditioned Atlas 10 lathe. Having some early issues, when I put aluminum rod into the chuck it appears to be noticeably out of alignment? What could be happening here,the rod appears to be straight - I tried this with a new drill bit and got the same result? What could be happening here, any ideas on what could be going on with the lathe?
Thank you,

Tim


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## benmychree (Mar 7, 2021)

Don't expect that set of chuck jaws to hold anything straight within close limits, they are made for holding large diameter parts within the large steps.


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## Ulma Doctor (Mar 7, 2021)

you may be experiencing a phenomenon known as runout
3 jaw chucks rarely run below .003" runout ( a set tru chuck would be the exception)
this usually is not an issue as the runout will be cancelled as the piece is reduced in diameter
in other words, the turned piece is true to the central axis of the headstock
even if you had .050" runout and reduced the diameter by .035", you would still (theoretically) have a perfectly cylindrical feature true to the axis.


secondary to that,
if the jaws were removed, and somehow not inserted in the correct timing, or in the incorrect slot, the zone in which the work is held is no longer in the center of the chuck. it has been offset by the incorrect positioning of one or more of the jaws in relation to the scroll that drives them.
if the jaws don't meet together in the center of the chuck, repositioning may be necessary


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## wa5cab (Mar 7, 2021)

First, Mike is correct.  If you look at the face of the chuck near the slots that the jaws run in, you should see the numbers 1, 2 or 3 stamped in the face of the chuck and on the side of each jaw.  If the numbers on the chuck don't match the numbers on the jaws, you need to back out the jaws until they are all free of the scroll, remove them from the chuck, and then starting with jaw #1 in slot #1, load jaw #1 into slot #1 and tighten the scroll until j #1 is captured.  Then rotate the chuck to bring slot #2 near 12:00 o'clock, slide jaw #2 into it and rotate the scroll enough to capture jaw #2.  Then do #3. 

Second, although the runout should still have been small, you don't have the right set of jaws installed for working on something as small as that rod.  The correct set of jaws will look like the set in your photo but turned around so that the longest jaw step is nearer the center than the other two steps on each jaw.


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## wa5cab (Mar 7, 2021)

And if you do not have the other set of jaws, you are going to have to buy another 3-jaw chuck.


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## Bi11Hudson (Mar 8, 2021)

On older machines, I have found the chuck body and the jaws to be unreadable or non-existant for registration numbers. I usually, even when I can read the numbers, try Jaw 1 in each of the slots with 2 and 3 following. Using a test bar from a printer spool, check for runout. When I've IDed the lowest runout, mark the chuck body and jaws with my own method. 

I have found even new chucks that weren't quite as "true" as they could be. Most "bargain" brands, especially out of China, aren't checked that close before they are marked. With a 3 jaw scroll chuck, having zero runout is rare for any given setting. Find the closest size to your "usual" work and measure from there. For hobby work, close is good enough. Just how close is a very personal matter. For professional work, where the higher cost can be justified, a good quality or even a "Set True" can be justified.

FWIW, I have a Craftsman 101.27440, a 12 inch version of the same machine. Each of several chucks is "loose" to some extent. If the jub requires close tolerances, I use a 4 jaw independent. If the OD is going to be cut down, it's a moot issue. Any part made where the OD has to be cut will be concentric as long as it remains chucked.

.


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## oldschoolcane (Mar 8, 2021)

I sure appreciate everyone's help and advice, I looked over the chuck and I can see the numbers on the chuck but not on the jaws? This chuck has had some pretty hard use and I think even the wear showing up on the jaws may be a factor also, the jaws do appear to come together correctly. I am starting to understand that some runout may not matter once the project is complete. The type of work I want to do on the lathe will be pretty limited to 1/4 to 1/2 light metal, should I try and find a new chuck or another older version to fit onto the lathe? I just need a chuck that fits the smaller work and the type of projects I want to do on it. Any thoughts about what chuck to look for and possible suppliers?


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## markba633csi (Mar 8, 2021)

The mainland Chinese chucks would be the cheapest but you need to watch out for quality control problems. If you can afford it, something like a Pratt-Burnerd would be a much better choice but pricey
I have heard good things about Sanou chucks, not sure if they are Chinese or Taiwan made
-Mark


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## wa5cab (Mar 8, 2021)

OK.  If you can still read the numbers for the slots on the chuck face, I think that I can tell you how to ID the jaw numbers.

Stand the jaws on the bench or table in front of you with the interrupted threads up and the short Vee gripping surfaces nearest to you.  The thread nearest to you will also be nearest to the bench surface.  The "first" thread is defined as the first one to engage the scroll when installing the jaws.  The jaw with the first interrupted thread nearest to the short Vee gripping surface and nearest to you is #1.  The one with the first thread farthest from you and farthest from the Vee is #3.  And the other one is #2.

The reason not to use the outside set of jaws (that are apparently all that you have) all the time is that if you are not careful, you may run the compound into the chuck jaws before before the cut is finshed


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## Bi11Hudson (Mar 8, 2021)

wa5cab said:


> Stand the jaws on the bench or table in front of you with the interrupted threads up and the short Vee gripping surfaces nearest to you. The thread nearest to you will also be nearest to the bench surface. The "first" thread is defined as the first one to engage the scroll when installing the jaws. The jaw with the first interrupted thread nearest to the short Vee gripping surface and nearest to you is #1. The one with the first thread farthest from you and farthest from the Vee is #3. And the other one is #2.


Good advice, _but_. . . There is an "old school" designation for chuck jaws being that what you have was called "lathe" jaws and the reverse was called a "drill" chuck. That's a very old designation from old books and I'm sure has been replaced by "inside" and "outside" gripping. Now that I've confused you a little, let's get even more so.

There are chucks, *rare but. . . *, that are both inside and outside gripping. Take the jaws out and look at the back side where they connect with the "scroll". They will be slightly curved to mate with the scroll. If they are curved on both sides, _no that's not a good description. . ._ If the jaw teeth form an oval on the back, a "truncated" oval, they *may* be inserted in either direction. Number 1 and 3 are swapped, based on the position of the teeth. Since the chuck body is numbered and the jaws are not, *and* it is obviously a very old chuck, it is _possible_ that you have lucked into this type of chuck. The style was rare for even on old machines, but did exist. Sold for "hobby" level machines. . . The largest I have ever seen is a 5 inch chuck. I have a 3 inch that has the reversible jaws, so I know they did exist. *You might get lucky*. . . If you have managed to acquire a reversible jaw chuck, up front I will offer to buy you a new chuck, with both sets of jaws, in exchange for your old one. Not a fancy one mind you, just something usable to a beginner.

A quick way to check for this style of chuck is to try to insert a jaw "backwards". Any one, if it won't get far enough for the second it isn't a reversable jaw. Just turning the key by hand lightly, do not use any force. If you do have a reversible jaw chuck, the jaws can be determined by setting them on a bench with the long jaw away from you so that they are tilted toward you. There will be a slight offset in the teeth. Set them in order so that there is a slight progression from one to the next. The one closest to you is number 1 for "lathe" usage. For "drill" usage, swap number 1 and 3. The slight progression is still there, just in the opposite direction.

One other point, not just for reversible chucks but for any. The teeth closest to the end of insertion will be number one. Try the set in each slot, one at a time of course. Chuck up a fairly smooth rod. I have a bar from an old printer, a piece of drill rod would do better. Run it around by hand to measure runout. When you have determined the best (lowest) runout, mark the jaws to match the chuck. Slow and methodical will pay off in the long run.


oldschoolcane said:


> This chuck has had some pretty hard use and I think even the wear showing up on the jaws may be a factor also, the jaws do appear to come together correctly.


Checking by eye is not sufficient. The ideal target is less than a thou. Realisticly, with an older chuck, a few thou is good. Try all three positions and ID the jaws to the best (lowest) runout, matching the numbers on the chuck body. Lining up visually means you have the jaws in proper sequence. The runout should be measured with some type of indicator. The difference cannot be seen by eye, unless you have* very *sharp vision. There are times when the human eye can resolve a half thou, this is not one of those times.

The nature of the closing mechanism, the scroll and teeth, will vary based on the diameter of the work. The optimum closure to measure is near the normal working area that fits what you normally do. If you use a 1/2 inch drill as a test bar, your measurement would be most accurate at that 1/2 inch. Smaller or greater diameters will tend to drift away from optimal from there. But as noted, if the OD of the work has to be sized, the whole issue is moot.

.


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## markba633csi (Mar 8, 2021)

And if that isn't enough chuck information, there's even more when you get to fitting a new chuck to your old lathe   
-Mark


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## Bi11Hudson (Mar 9, 2021)

Naw. . . Not really. The spindle nose is threaded for 1-1/2X8. Unless it has been modified. . .which is unlikely. There are (were) many chucks sold with backing plates already threaded for that size. It is a fairly common nose thread for middlin' size lathes, particularly  American made "old iron". If the chuck and the backing plate are acquired seperately, it becomes a bit more difficult, but not that much more so. But it does complicate the knowledge base needed by a beginner. He had enough sense to get his hands on an older, basic machine and clean it up so is definately not a bozo loser. Just needs a little help now and again.

.


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## oldschoolcane (Mar 9, 2021)

I am reading through all this information and I am trying to figure out what I need to do? Essentially, I will probably only use this lathe for making rod building components which are usually small and light weight soft metal, german silver, aluminum etc. So early on we discussed that the 5 inch chuck is to big and won't work best with 1/4 and 1/2 inch projects. So, rather than trying to make the original chuck work shouldn't I just find a better chuck to use with the lathe? I just need a smaller chuck in good condition to solve this problem so that I can continue to learn how to use my lathe.


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## Bi11Hudson (Mar 9, 2021)

The 5" chuck* is* small.

.


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## oldschoolcane (Mar 9, 2021)

Bill, I just found 2 of the missing chuck jaws, with the longer step towards the center. Now I am wondering how to find another jaw that will complete the set? Any ideas? So your saying the 5 inch chuck is the right size for what I am trying to do with the lathe? The chuck reads, Union Mfg. 5 in., No. U 435


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## Bi11Hudson (Mar 9, 2021)

Sir;
There are a number of options available to you. *Some* chucks were built to a standard for jaw fitting. You *might* find a set of jaws that would fit. I would be sceptical of replacing only one, of trying to get near zero runout with one odd piece. Another option would be to acquire a (used) chuck and just replace the existing one. If possible, find the same chuck so you could share backing plates. Swapping inside to outside bodies would be cumbersome but doable. Even possibly using the jaws without changing the chuck body. That would be a matter of how close you came to finding the same chuck. These options would all be contingent on finding parts that would interchange. That *could* get real expensive real fast and you might find yourself with a pile of unusable parts and still facing the original problem. 

Now, to digress for a few and talk about chuck sizes. As far as "old iron" lathes go, the Atlas 10", any model, is considered a "light weight" as far as industrial machines go. There are many the same (M/L) size, the Atlas is toward the light end of that spectrum. My machine is a Craftsman 12(X36) which is basically the same machine on "riser blocks". An excellent machine for occasional "light" work, not so good for production work. It was acquired from a cotton mill in S. Carolina. Indirectly, but that was the original purchaser. Mine came with the same chuck as is on yours, but with "inside" gripping jaws. Chuck sizes go up from there, with "shipyard" and rolling mill lathes having chucks many *feet* in diameter. Many such lathes have smaller chucks that fit the large ones with "blind" spindles. Small chucks for small work. . .

I have a couple of other lathes and mostly do model(H-O Trains) work. I sometimes get into other work repairing "stuff" and the occasional odd "big project". I have a Grizzly 9X, a mini 6X, and (used to have) a UniMat DB-200, basically a jeweler's lathe at (3") 75mm. The Grizzly G-1550 has the same spindle threads as the Craftsman(Atlas), 1-1/2X8, and I find myself more comfortable with the 4 inch chuck for personal reasons. Mostly because it was new and had low runout from the factory. I also have a 3 inch 3 jaw from the UniMat that I have "adapted" to the much larger machines. But to make such an adapter requires some advanced knowledge. But something I would *not* recommend for a beginner. Not that I am an advanced machinist, I'm an electrical engineer. But hobby machining is necessary for other hobbies as well. I also have larger chucks, both an 8 inch and a 9 inch. Both 4 jaw independent and both very cumbersome (heavy) to deal with.

The bottom line here is that a smaller chuck is available, from the parts list for a *smaller* machine. But lucking into one is about as rare as finding the odd jaw for your chuck. Most Chinese lathes are threaded for metric, M39X4. *Grizzly* and *Jet* are two I know of that (*in the past*) did manufacture a lathe threaded for 1-1/2X8. I don't know if parts are still available, but it could be worth a try. Otherwise, I would recommend eBay or the like to acquire a replacement, looking for a 4 or 5 inch, with threaded back plate. A mini, some 3-1/2 inch diameter *is* available. But that small doesn't use a backing plate like the bigger machines. They *could* be fitted, with sufficient work, to a larger machine. I personally would recommend against it unless there was an over-riding need for such a small chuck.

Any larger on your machine would be asking for trouble. That would take some time at best, looking for something at a price you would pay might be even longer. What ever you end up doing, make sure a backing plate is included or *can be acquired* for your spindle nose thread. At this point of your (assumed) knowledge, I would recommend against replacing a single jaw on your existing chuck. The wear, hence runout, could well be atrocious. Or possibly a drop in. If you do replace them, replace all three as a set. It is possible to grind to fit a single jaw, but that is something that requires a little more knowledge of your machine.

I find myself drifting into preaching or teaching mode so will back out for now. I will follow along anon and answer any question you have. But I've talked far too long now and will drop out.

Bill Hudson​
.


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## oldschoolcane (Mar 10, 2021)

Thanks Bill, I sure appreciate the help with this! I think I have a better understanding of what I need to do. What I originally thought was that I needed a smaller chuck for the smaller work but now I understand that its the smaller jaws on a 4-5" chuck that is most important. I would like to use the chuck that came with the machine but maybe that's not possible now? I'll just have to see what my options are, I just want to be able to use my lathe.


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## markba633csi (Mar 10, 2021)

A 5" would be a nice size for your Atlas 10"   Also you might want to consider a collet set in addition to a chuck
-Mark


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## Bi11Hudson (Mar 10, 2021)

markba633csi said:


> A 5" would be a nice size for your Atlas 10"   Also you might want to consider a collet set in addition to a chuck
> -Mark


A very good suggestion, Mark. Especially for the anticipated small work below a half inch. To acquire a collet chuck would also buy time to watch for a suitable 3 jaw. I have a small collet chuck(ER25), but use it so seldom it never occured to me as a possibility. The lathe will accept a *MT-3* taper in the headstock. The through hole is a fuzz over *3/4 inch.* An ER25 or ER32 would be suitable for long stock. A larger size would work but wouldn't feed large stock. That's one of the calls that the individual has to make. It _can_ get expensive later if the buyer gets too small or too large. To find one with the backside threaded for a drawbar would be preferable. In the range of anticipated use, a hollow drawbar can be finagled, allowing long stock to be fed through.

Further, while scrounging around for small tooling, I have seen several small (3-4") 3 jaw chucks with a straight shank. I don't remember specifics, particularly pricing, just something that caught my eye. To mount such a chuck in an ER chuck would reduce accuracy to some extent. But a 3 jaw is not known for accuracy to start with. It definately would expand the options while looking for a solution to the overall problem. The one that comes to mind is a 2-1/2 inch, threaded for M12X1, that has a straight shank. It's what I used to make a MT-3 adapter. (MT-3 to Jacobs taper to M-12) It uses tommy bars rather than a key so is suitable only for light work. But a possible "drop in" so;ution.

.


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## markba633csi (Mar 10, 2021)

Good points, Bill.  A small set of MT3 collets and a piece of allthread and a nut and washer for a drawbar would be one easy way to go


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## wa5cab (Mar 11, 2021)

The 5" chuck that you have probably was bought from Atlas with the lathe.  If it is like the 6" Union chuck that came with my Atlas 3996, it does not have a backing plate.  The rear of the chuck body is threaded 1-1/2"-8.  If you found the #2 and #3 inside jaws, the #1 is probably there somewhere.  If not at your house, it would be worth a trip back to where you bought the lathe to look for that one jaw.

If all that you wanted to do with a collet set was to hold milling cutters, the least expensive choice would be a full set of 3MT and a 3/8"-16 draw bar.  These would directly fit the spindle nose taper.  However, if what you want to do is hold 3/4" or smaller work, the 3MT wouldn't be a good choice as they only come in 1/16" increments and you can't pass the work through them because of the draw bar and 3MT arbor.  I have a 3MT set, a 3AT set and a 5C set, the latter two of which can pass stock or work through the spindle.  However, the last two would be pretty expensive to acquire a full set of today.  I would suggest either ER25 or ER32, and only with a 1-1/2"-8 threaded collet chuck so that you can pass stock through the spindle.  But do not buy a collet chuck with either straight shank or 3MT mount.  Neither of these types will allow you to pass work through the spindle.  Plus the 3MT requires a draw bar to be safe and the straight shank requires a 3-jaw or a 4-jaw chuck to hold it.  Otherwise, the only drawback to the ER collets with threaded chuck is that of all of the types of collets, they are the slowest to load and unload.  However, unless you have a job to make a bunch of parts, that isn't a major problem.


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## JPMacG (Mar 11, 2021)

A number of us have made our own ER collet chucks that screw onto the 1-1/2 x 8 spindle.  I made one for ER40 and am very happy with it.  There are several tutorials on how to make them.  It is a good learning experience.

By thew way, the runout on my 3-jaw is about .014 peak-to-peak.  It is a 5" Atlas chuck I assume came with the lathe when new, as Robert said.  The chuck has a date stamp of 1951 but is in nice condition.   So I assume that even when new the stock Atlas chuck's runout was not great.


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## wa5cab (Mar 11, 2021)

AFAIK, Atlas never published the expected runout figures for their stock chucks.  However, 0.014" isn't very good.  And you didn't say at what diameter you got the figure.  A well-used chuck may have some flat spots on the scroll.  I would suggest that it should be checked at about 1/8" increments say from 1/8" to 2" or larger.  And check the actual spindle runout first as it will either add to or subtract from the chuck figures..


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## JPMacG (Mar 11, 2021)

It was a few years ago that I made that measurement - I don't remember the details at this point.  I have work on the lathe, which I don't want to disturb, or I would check now.  The socket on the 3-jaw chuck does not seem to be a precise fit onto the spindle registry.  But the socket doesn't look damaged or worn.  The runout on the spindle registry is good - around .001 or maybe better.

I seldom use the 3-jaw anymore.  If the workpiece is under 1" I use the the collets, otherwise the 4-jaw.


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## wa5cab (Mar 11, 2021)

OK.


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## oldschoolcane (Mar 12, 2021)

I found and purchased another chuck with the correct jaws, its an original Atlas 5" chuck and in good condition. Now I need to consider the collet chuck option as well. I am familiar with collets, but not entirely are they only usable when inserted into a collet chuck? Or can the collets be used in the normal 3 jaw chuck? Sorry, I guess I just don't understand the limitations. I also need a Jacobs chuck, is there a size and model that would be most usefulfor the Atlas 10?


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## JPMacG (Mar 12, 2021)

Here is my thread on making an ER40 collet chuck for my Atlas 12".   I pretty much copied the work of others.









						Yet another ER40 collet chuck for an Atlas
					

Just completed an ER40 collet chuck for my Craftsman (Atlas) 12-inch lathe.  I followed the excellent drawing by Ronald Crowell, Harold Hall's website, and the many YouTube tutorials.  This was a real nice learning experience with a variety of operations... boring a precise diameter, internal...




					www.hobby-machinist.com
				




I'd like to have a Jacob's chuck with a through hole that mounts to the spindle, but they sell used for over $100 used and many of them look well worn.  I don't think anyone makes new ones currently.  The ER40 collet chuck does almost everything a Jacobs would do.


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## wa5cab (Mar 12, 2021)

First, for what is available that would easily fit the Atlas 10, there are basically three types of collets.  The 3MT collets fit the taper in the spindle directly and only require a 3/8"-16 drawbar to operate them.  If what you want to do is to hold milling cutters, they will be the least expensive option.  However, they only come in 1/16" increments and do not allow you to hold work pieces that are much longer than the collets nor are of a diameter in between 1/16" increments as the gripping range isn't continuous from 1/16" to 3/4".

The other two common types of collets are typified by the 3AT (what Atlas normally sold back in the day) and the European ER.  .  The former requires a closer-adapter that directly fits the 3MT spindle on a 10" or 12" Atlas (and other makes of similar sized machines such as Logan/Wards, Clausing and South Bend) and a draw tube inserted through the spindle from the left end that screws onto the collet after it is inserted into the adapter.  The 3C collet is similar enough to the 3AT that it is easy to get confused with them if you have a pile of both.  Both are available in diameters from 1/64" to 1/2".  These have the ability to pass the stock through the spindle if you are making a lot of identical small parts. from the same stock.  If you had a bed or tailstock turret, you would have a stop set up in one of the turret positions.  And part off the previous completed part, index the stop to the active position, slide the stock piece forward against the stop, close the collet, and proceed to make the next part.

The draw tube came as part of two types of closers,  The simpler and cheaper type had a hand wheel on the left end that you used to tighten the collet onto the stock.  Most of the more expensive types had a lever with stops that you used to tighten or release the collet with.  Theoretically you did not have to stop the lathe after parting off the previous part in order to advance the stock for the next one.  But I have never tried it.

The much more common 5C collet looks like the 3AT and 3C but about twice the diameter.  And the draw tube is about twice the diameter.  So to use either the hand wheel or lever operated closer requires a larger lathe with larger spindle taper.  However, the Chinese make several brands of collet chucks that will fit the Atlas 10" and both 12".  Plus Royal once made a front-mounted lever operated closer that screwed onto the spindle threads and could handle stock up to 3/4" diameter through the spindle.  And short parts up to 1-1/16" diameter.

The ER collets are made similar to the collet used by Dremel except larger.  They are identified as ER11 through ER50 (AFAIK).  Of possible interest to you would be ER25 (.047" to .625"), ER32 ( .109" to .781") and ER40 (.125" to 1.000").  Their closers are often referred to as collet chucks and can be bought or made to mount with a straight arbor, a tapered arbor or with female threads to screw onto the spindle nose threads.  Most people who make them buy the closer nut.  Whether you buy or make, I would recommend one with 1-1/2-8 threads unless you have a special need that favors either of the others.  If you do opt for one with a 3MT tapered arbor, it must be threaded for draw bar and you must use a draw bar  or sooner or later you will live to regret it.


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## Bi11Hudson (Mar 12, 2021)

oldschoolcane said:


> I found and purchased another chuck with the correct jaws, its an original Atlas 5" chuck and in good condition. Now I need to consider the collet chuck option as well. I am familiar with collets, but not entirely are they only usable when inserted into a collet chuck? Or can the collets be used in the normal 3 jaw chuck? Sorry, I guess I just don't understand the limitations. I also need a Jacobs chuck, is there a size and model that would be most usefulfor the Atlas 10?


Ans. 1) Collets fit a tapered receptical in the collet chuck. That taper varies depending on the style of collet. "ER" is the most well known _currently,_ but there are many including an MT-3. But hang on to your wallet when you go looking for one. The collet alone should not be used in a 3 jaw.

Ans. 2) I have, and occasionally use, a Jacobs chuck that fits the 1-1/2X8 spindle nose. But I suspect what you are asking after is a tailstock chuck. The tailstock is MT-2, which is a fairly common size for smaller (<1") drill presses as well as lathes. As with most machine tools, the cheaper the tool the higher the runout. That is a "rule of thumb" and you may stumble into a zero runout chuck for $10 bux. But don't expect it. . . 

Most chucks have a "Jacob's Taper" mount, with MT-2 to Jacob's adapter. That combination is readily available with a wide price range. Just remember and heed the rule-of-thumb above. The Jacob's taper has several sizes. If bought separately, be sure of the sizes. Also available from _some_ Sears stores is a 1/2 chuck with 1/2-20 threads and the corresopnding MT-2 to 1/2-20 adapter. They are getting rare but still can be found.

.


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## wa5cab (Mar 13, 2021)

As Bill wrote earlier, the tail stock arbor has a 2MT taper.  So don't buy any drill bits with 3MT tapers.  And you probably don't want to pay the extra money for a 5/8" or 3/4" maximum capacity drill chuck as except for Silver & Demming, the majority of drill bits over 1/2" capacity will be MT.  . 

 When picking the tailstock drill chuck arbor, the shorter JT (Jacobs Taper) end must match the drill chuck taper.  The longer MT end should be 2MT.  If the 2MT end has a narrow flat tang on it, cut it off and carefully grind the cut surface flat.  The Atlas tailstock had a feature whereby as you retract the ram, the 2MT arbor runs into the end of the 5/16" ram screw and ejects the arbor from the ta[er in the ram.  Using a tanged arbor will cost you about 1/2" of usable ram travel.  The most accurate way to do it is to fasten a short piece of half inch round stock in the drill chuck.  Use the loose end of the round stock to mount the drill chuck in your 3-jaw spindle chuck.  Put the lathe in the slowest back gear speed.  If you don't have a tool post grinder, jury-rig whatever you do have to the compound and with the lathe running, grind the small end of the arbor flat.


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## wa5cab (Mar 13, 2021)

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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## craniac (Mar 13, 2021)

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


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## wa5cab (Mar 13, 2021)

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.


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## oldschoolcane (Mar 14, 2021)

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.


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## wa5cab (Mar 14, 2021)

@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.


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## Bi11Hudson (Mar 14, 2021)

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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## wa5cab (Mar 17, 2021)

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.


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## Bi11Hudson (Mar 19, 2021)

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.


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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## wa5cab (Mar 20, 2021)

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!


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## Bi11Hudson (Mar 20, 2021)

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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