# 109.21280 Craftsman Lathe - Newbee Questions



## budzinsk (Mar 14, 2021)

Hi Everyone.  I just bought a 109.21280 Craftsman Lathe.  First lathe I owned.  I did spend 2 years in votec for Machine Shop but that was over 30 years ago.  I got this to play around with it.  It came with a 5" 3 jaw chuck, but it does not fit the lathe - the plate does not match up.  I am not sure what the chuck was from, but would it better to sell it and get the exact chuck for this if I can even find it?  Or is there a way to make this fit the plate I have?  Also, how would I go about getting the plate off?  Thank you!


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## Ulma Doctor (Mar 14, 2021)

Hi @budzinsk !
welcome to the forum.

if you are attached to the old chuck, you could turn the backplate in place to the desired size
that is ,of course, if the backplate is oversized.
if the current backplate is undersize, you'd do better to construct a new one or purchase a commercially available unit
you'll need to ascertain the bolt circle for the intended chuck to mount to the modified plate
to get the old plate off, i would entertain the thought of bolts protruding from the present faceplate, and a lever of suitable material
i would then hold the spindle by either internal or external means (as simple or complex as you would like to make it)-
an expanding arrangement for internal spindle holding, a compressing arrangement for external holding
wedges could be employed to lock the spindle
as could a strap wrench
the spindle threads are right hand threads, the faceplate will come off with counter-clockwise rotation
avoid banging on the lever with repeated blows
you may wish to abandon hammering altogether to preserve the integrity of the spindle bearings, 
unless the intention is to replace the bearings- then by all means hammer away 
if the faceplate is really stuck, the application of penetrating fluids would be advisable
i can attest to Colonel Red's Antirust elixir for a penetrating fluid for this purpose, i have done it 3 times on crusty chucks

it's very simple to make.. 
1 part ATF (automatic transmission fluid- any kind works) 1 Part Acetone, 1 Part Kerosene (No.1 Diesel fuel will work in a pinch)
combine in a metal or suitable plastic container and shake heavily

how to use it...
apply very liberally to the surfaces adjacent to the threaded area, numerous times over a week period- if the faceplate appears very stuck
fewer applications may only be necessary and the static time frame would also be reflective of the corrosion present.

the Colonel Reds can be used as an anti-rusting solution, if used as a preemptive external coating before storage of easily oxidized metals


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## benmychree (Mar 14, 2021)

Be very careful of hammering, and do not use the back gears to lock the spindle, the gears are made of pot metal and could be easily damaged.  There was a posting recently where the guy was having the same problem removing the chuck, he made a curved wedge with several gear teeth on it's inner face and a lug to seat against the headstock top surface, it was made of hard wood, he inserted it against the bull gear and used some sort of wrench or lever to break loose the chuck/backplate.  The teeth on the block can be traced against the bull gear and carefully sawn out, they should be nicely fit to the gear teeth to share the strain against the several teeth.


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## budzinsk (Mar 15, 2021)

Ulma Doctor said:


> Hi @budzinsk !
> welcome to the forum.
> 
> if you are attached to the old chuck, you could turn the backplate in place to the desired size
> ...


Thank you so much for the detailed explanation!  I appreciate the quick and detailed response.


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## budzinsk (Mar 15, 2021)

benmychree said:


> Be very careful of hammering, and do not use the back gears to lock the spindle, the gears are made of pot metal and could be easily damaged.  There was a posting recently where the guy was having the same problem removing the chuck, he made a curved wedge with several gear teeth on it's inner face and a lug to seat against the headstock top surface, it was made of hard wood, he inserted it against the bull gear and used some sort of wrench or lever to break loose the chuck/backplate.  The teeth on the block can be traced against the bull gear and carefully sawn out, they should be nicely fit to the gear teeth to share the strain against the several teeth.


Thank you for the response and advice!


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## CluelessNewB (Mar 15, 2021)

If you look at the old Sears catalogs you will find that the largest chuck they offered for the 6" lathes (both 109 AA and 101 Atlas) was 4".  Even if you can fit that 5" chuck you will not be able to use the capacity because the jaws will extend too far on large items and will hit the bed.  If it were me I would keep the backing plate, sell the chuck and look for something more appropriate.


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## budzinsk (Mar 15, 2021)

CluelessNewB said:


> If you look at the old Sears catalogs you will find that the largest chuck they offered for the 6" lathes (both 109 AA and 101 Atlas) was 4".  Even if you can fit that 5" chuck you will not be able to use the capacity because the jaws will extend too far on large items and will hit the bed.  If it were me I would keep the backing plate, sell the chuck and look for something more appropriate.


Thank you!  I would like to find one that would fit the backing plate without modifications, but I assume that will be a long shot?


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## CluelessNewB (Mar 15, 2021)

BTW you may want to upload some pictures of your lathe over on the Vintage Machinery web site.  I don't believe that they have a photo of that model. 

http://www.vintagemachinery.org/


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## budzinsk (Mar 15, 2021)

CluelessNewB said:


> BTW you may want to upload some pictures of your lathe over on the Vintage Machinery web site.  I don't believe that they have a photo of that model.
> 
> http://www.vintagemachinery.org/


Thanks.  I just registered and uploaded the picture.


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## wa5cab (Mar 17, 2021)

@budzinsk,​
Back in 2017 and again in 2018, two other people also reported having a 109.21280.  I have been through the nearly complete run of Sears Power Tools catalogs but don't find it listed.  If anyone ever does, please let me know.

One of the two previous reports said that the spindle nose threads were 1"-10, which is the same thread as found on the Atlas 612, 618, 3950 and 10100.  And the Craftsman 101.21400 and 101.21200.  However, he reported that chucks with that tread would only go onto the spindle about one turn.  Someone asked about it maybe having 1"-8 threads like the Craftsman 101.07301 but he apparently never answered.  So we still don;t know what the correct answer is.  If you are successful in removing the face plate or backing plate from your spindle, please measure and report what threads you found.

Can you make and post a few more photos of your machine?  In particular one or more that will show what type of back gears it has.  FYI, all of the Atlas built lathes have a large gear (commonly called the Bull Gear) and a separate small gear (usually called the Spindle Gear) on the spindle and a back gear with the same size gears but in the reverse order mounted either to the rear of or underneath the spindle.  By contrast, the 109.21270 and two earlier Sears models that we know anything about all three have a planetary gear assembly mounted approximately where the Bull Gear is located in the Atlas machines and in almost all other lathe brands that we know anything about.

Also, as a general comment, "pot metal" is usually a deliberately derogatory term used by people who either don't know any better or who want to imply without quite saying so that all of the machines made by Atlas and AA are worthless junk.  Its use in that manner will not be tolerated on this site.


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## budzinsk (Mar 17, 2021)

Hi.  Thanks for the response.   Here are some more pictures.  I need one of the small handles - you can see someone used a socket.  If anyone knows where to find one, please let me know.  Also, what size taper is the chuck?  it shows a J2, is that the same as a M2?  Thank you.


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## CluelessNewB (Mar 17, 2021)

wa5cab said:


> I have been through the nearly complete run of Sears Power Tools catalogs but don't find it listed.  If anyone ever does, please let me know.​



I was curious about it also.   Over on the VM site the AA-80 appears in the 1960-61 tool catalog.   Also the Craftsman "crown" logo seems to have appeared around that time.  There is no 1962 tool catalog that I can find anywhere online.  The 1963 tool catalog has no AA lathe.  Was it maybe only offered in 1962?


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## benmychree (Mar 17, 2021)

So, call it by it's proper name, Zamak; the point that I was making was that it does not have the strength or durability of other commonly used materials such as cast iron or steel, I was urging being careful in trying to remove the chuck to avoid damage to the gearing due its lesser durability.  The term "pot metal" is merely slang for the same material, not intended as a slur.


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## wa5cab (Mar 18, 2021)

Calling something Pot Metal in its simplest terms means that you have no idea what was in the pot when it was melted.  Which is also true if you just say "cast iron" but isn't true of Zamak 5 which has a well defined composition.  I didn't look into the variables but two different sources give the tensile strength of Zamak 5 as 48,000 psi and of gray cast iron as 9,500 to 60,900 psi.  But be that as it may, the fact remains that the term "pot metal" is mainly used as an insult or is indicative of lack of knowledge on the users part.  So don't use it on this site.

The rear view photo of the 101.21280 indicates that the back gear mechanism is a heavier version of the planetary gearbox arrangement used on the 109.21270 and earlier models.  However  we can't tell anything about the Sun gear or the probably three intermediate gears or how the cone pulley is coupled to the spindle.  So I would probably attempt to remove the spindle from the headstock with the drive or backing plate in place if it doesn't want to come off.  And then figure some way to hold the spindle and remove the plate.The exploded view drawing of the 109.21270 is in Downloads.  And I think that the instruction sheet for converting the 109.0702 to a 109.0703 which is mainly how to install the back gears and may be of some help.


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## Manual Mac (Mar 18, 2021)

I just looked up your lathe in the archive at tonylathes. 
They have information & photos you will be interested in.


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## budzinsk (Mar 18, 2021)

Manual Mac said:


> I just looked up your lathe in the archive at tonylathes.
> They have information & photos you will be interested in.


Thanks.  yes, I saw that.  Nice pics out there.


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