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Lathe Spindle Nose details & Standards

smokepolesc

Aluminum
Joined
Mar 24, 2006
Location
South Carolina
The challenge of identifying various lathe chuck adapters and face plates can be pretty daunting. The following bits of insight and sources of hard information are offered to assist in that endeavor.

The standard lathe spindle nose styles are threaded, "A1-5...A1-20" type; "L00...L3" - Long taper drive key, and D1-3...D1-11cam lock. These are well documented in the handbooks noted below and have changed little over the years. he comments below addres the threaded types, which have far more variation and are what are most commonly found on earlier machines.

Threaded spindle noses were the norm for all tool room lathes and most production lathes until the 1920’s when the A, B, and cam lock types came into use. Unique sized threaded spindles were often preferred by many machinists to do small high precision work on precision bench lathes because the “production” machines couldn’t use their tooling.


Prior to WWII, each lathe manufacturer had their own version of the “standard” spindle noses. They did this to keep their customers coming back to them for replacements and new tooling. I have seen a number of early South Bend, Sheldon, Logan, etc. lathes that were supposed to be 1½ x 8 or 2¼ - 8 and the chuck adapters from one would loosely fit the other, but the not visa-versa. In many cases, they are not interchangeable. The diameter and length of the cylindrical “land” in front of the shoulder and the thread per inch, and in some cases, the thread form could vary from maker to maker.

Because the resulting chaos interfered with WWII production, the US government forced the issue. The first generation of the ANSI standards listed below were adopted in 1943 for lathes and milling machines. The CURRENT standards listed below are referred to in chapter 40 of Tool and Manufacturing Engineers Handbook; 3rd Edition; Daniel B. Dallas, Editor; Society of Manufacturing Engineers; McGraw-Hill Book Company; copyright 1959 & 1976. Similar references will be found in Machinery’s Handbook.

The current standards are not the same as the pre-WWII versions. One source of information for early specs would be the pre-WWII editions of Machinery’s Handbook. British and European makers have had their own independent standards for many years, but currently conform to the ISO (International Standards Organization) standards which are generally in line with the current ANSI standards.

ANSI - American National Standards Institute, New York
“Machine Tapers” ANSI B5.10-1963
“Spindle Noses and Tool Shanks for Milling Machines” ANSI B5.18-1972
“Spindle Noses” ANSI B5.9-1967


Prior to the introduction of the ANSI standards in 1943, South Bend lathes seemed to be closer to the nominal threaded spindle size, a 2¼ - 8 spindle had a 2.250 land diameter, 8 threads to the inch, with a 2.250 max thread OD. Others makers of 2 ¼ - 8 varied significantly, from a smaller 2.150 land diameter with smaller OD threads to 2.315 land and larger diameter threads.

To illustrate, I have a Sebastian gear head 12 x 36 bench lathe, manufactured by Sheldon for Sebastian in 1941, that appears to have a 2 ¼ - 8 threaded spindle. In reality, the land measures 2.157. A 2 ¼ - 8 South Bend face plate is very loose. The Sebastian came with a small face plate which has a 2.275 land and 8 threads to the inch that will actually spin on the spindle. It also came with a large face plate that appears to have been made by South Bend with a 2.25 land and 5 threads to the inch. I suspect this one is for a milling machine. Many early horizontal mills had a threaded spindle nose with a non-standard coarse thread such as 2 3/16 – 6 or 2 5/16 – 5. Lathe chucks were sometimes fitted to the mill spindle and used for grooving and facing operations like a lathe.

Please feel free to correct any errors and add to this! I really struggled with a couple of machines to figure out what the spindle nose was and where to look for tooling.

SmokepoleSC
 
"Standard" (I.E.) Long Taper and Cam Lock spindle noses appeared more like in late thirties, not twenties.

For instance, there are Lodge & Shipley sales brochures a few months apart in 1937. The earlier shows the old L&S "double nose" (forerunner of "L" type) that had been around since the early teens. The later brochure shows the Long Taper type.

John
 
Monarch's flanged spindle nose appeared in 1930, and the cam-lock was adopted around 1933. There was a joint patent of the cam lock nose (it was one of these times where I came across it while search for something else, and I never went back to print it out), but if memory serves me it carried the names of like 10 or more people from a range of lathe builders. Someone might want to search for it and get more historic infomation.

John
 
Monarch's flanged spindle nose


I had one of these. 22" "M" S/N CM4742 .

Just a plain flat flange if I recall.

Its still chugging away over on the east side.

Still have a pair of new half nuts for it :D

John
 
I have tried to find the specs for the D1-6 so I can make a chuck back to mount my 4-jaw on my Monarch CK-12. Never found the specs. I will have to measure my lathe and wing it I guess.

Steve
 
You said:

"The standard lathe spindle nose styles are threaded, "A1-5...A1-20" type; "L00...L3" - Long taper drive key, and D1-3...D1-11cam lock. These are well documented in the handbooks noted below and have changed little over the years."

Did you mean to say that the A1-5, D1-5, etc were "unthreaded", as they rely on a taper to center the chuck and either bolts, or camlocks to hold them in place?

Machinehead61 - As for the D1-5 mount dimensions, are they not found here? A1-5 and D1-5 being identical, except for the bolts/camlocks used to hold them to the spindle.

http://shopswarf.orcon.net.nz/chuckmt.html

Or did you mean the dimensions of the chuck recess itself, which can vary from mfg to mfg. Most of the catalogs state that you have to use their proprietary back, but I could not prove that one way or the other.
 
I have a copy of USAS B5.9 1967. Tells WAY more about all these "standard" spindle noses than you ever wanted to know - including how to make all the gauges.


John
 
Thank you very much. I've googled for that info and never found it. How did you guys find it?

That taper will be the hard one, as I suspected. I assume that the chuck back is snug on the taper but the back side is what it sits flat against. Now to figure out a way to measure that 4.188 -0.0/+.0005 with the part in the chuck. Micrometer over gage pins appeals to me but how to make sure those pins are exactly 180 degrees apart without taking the thing out of the chuck, not to mention holding them there while measuring over them. I think I can set the compound at 7 deg 7-1/2 " with a 5" sine bar and indicator on the compound. Draw up the gage pin/taper geometry on autocad to get the over-pin dimension. This is what makes machining fun, creativity. Man I miss it.


Steve
 
Pretty easy to make up a ball gage for tapered bores. Two ground blocks skewered on a rod they can be clamped to. A tooling ball in each block. You set blocks against the front face and adjust the balls to the biggest mic reading you can get without lifting blocks off face. Trig tells you what over balls dim you need, using whatever the ball dim. turned out to be from block faces.

As far as USAS B5.9, the USAS has changed over the years, but whatever the current standards organization is (was ASA not too many years ago, and has, as far as I know, always been a sub of ASME), they will still have B5.9 for sale.

John
 
Machinehead61:
I went through sort of the reverse of what
you need to do when I made a back to adapte
a D1-11 chuck to my threaded spindle.

I made a back like you would for a flat back chuck
and then turned the the face back to create
the tapered pilot. Functionally all the tapered nose does is serve is a centering pilot.

Since I was mounting a fairly large 4 jaw (20") which was destined to never turn very fast, for me a little runout wouldn't matter anyway.

I turned the taper close and finished it with a file. I also made it vastly shorter than the spec. and finally I replaced the cam studs with threaded studs and bolted used them to bolt the chuck to the baacking plate.

You are doing just the reverse of what I did however, and your part has to be more difficult.

Drilling the 6 holes in the right place I see as the most difficult.--- Getting the taper exactly right isn't necessary for the project to work, If it comes up tight anywhere on the nose
it will work, but if the holes for the holding cams are haywire, it won't work at all.
 
I think the taper angle is shown as 7 degrees 7 1/2 minutes if I read the drawing correctly?

Don't think the back of the chuck fits snugly against the mounting plate, but instead the taper provides the register and the bolts/pins pull it tight evenly. It would seem to be too difficult to machine the taper so it came tight at the same point that the chuck back touched the mount.

As Robert points out, it only needs to come up tight somewhere before it bottoms out. Using most of the taper face is preferable of course.

As for where I found the page I linked, another member linked it once and it was bookmarked. If you Google for A1-5, or D1-5 spindle specifications, the link will come up as number eight on the first page of results.
 
My assumption was sort of the opposite of what you wrote.

The 'long nose' clearlly mounts on the taper
and never reaches the flat shoulder.

however my assumption about the short nose was that the chuck pulled tightly against the flat face, with the tapered 'spigot' as one name for it
simply provided register, as I see the taper as too short to prevent misalignment if the bolts
or cams were tightened unevenly.

In summary, on the 'short nose' which describes the A dnd D1 mounts, I see the taper providing thte same function as a 'dowell'.
 
johnoder
Two ground blocks skewered on a rod they can be clamped to. A tooling ball in each block. You set blocks against the front face and adjust the balls to the biggest mic reading you can get without lifting blocks off face.
I had a brain cramp when writing my post, I saw the diagrams of the spindle and thought external, not internal. Your idea is interesting but leaves me with questions.

I intend to use ball bearings for gage balls and a "tooling ball in each block" gives me no idea how you attach them.

To get "over balls dim" sounds like you are using gage balls that are outside the bore where an outside mic can go over the apex of both balls. My thinking tells me that this 7+ degree tapered bore won't allow the apex to extend beyond the edge of the bore enough to get a mic over it. As the bore angle approaches 0 degrees, the ball apex will be forced to approach the very edge of the bore. At 0 degrees (no taper) the ball apex must be inside the bore and thus impossible to mic over.

Steve
 
Tooling balls are precision balls of varying sizes with integral precision ground cylindrical shanks.

Easy to put in press fit reamed holes.

Some have sholders - making it easy to have a fixed, precise dimension from face of block to center of ball - necessary for calculation of over ball dimension.

The assembled ball gages are used in a way similar to telescope gages - in that they are fitted to the tapered bore, withdrawn and checked with a mic.

This is not theory - they are used all the time in shops around Houston that have do deal with making the tapered seat ring grooves in flange faces.

John
 
Thank you johnoder, I have learned something new, tooling balls.

robinr, I'm getting pretty tight on my funds, it would be cheaper to make the adapter, pins and all. Don't know how much longer I can afford Internet but we use it for ordering medical supplies for my son. A young friend came over yesterday who is also very tight for cash. The power window on his car died and he doesn't have the money to replace it so we did some cutting and made a window crank so he could manually roll the window up and down.

I'm meeting more and more people who are getting to the end of their financial rope. I'm hoping we can avoid a medical bankruptcy due to my son. Time will tell. If we do go bankrupt I'm hoping to hang on to my equipment. I use it more to help out people who can't afford new things rather than as a hobby. I saw this coming and managed to pay off our house and buy my lathes, mill, saw, and tooling a few years back when my father died and he left some money. I didn't want to waste my entire inheritance on medical bills just so some doctors can vacation in the Bahamas. I haven't had a weeks vacation since 2003. The more I can repair stuff or make it myself, the less we spend.

We just paid our property taxes ($1,590 for our 2-bedroom 900 square foot home) and that left us with less than $1,000 to our name. Not looking good. Glad our teachers got an 8% increase in my property taxes over last year so they can have a pension that I could only dream of getting. Looks like retirement for me will be when I'm dead.

Steve
 








 
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