Thanks, Robert. One other question. In the table attached to the heavy
cast iron cover is a column called 'Spindle Stud Gear.'? I'm assuming
this is the threading gear that is attached to the back end of the
headstock spindle. The one on my lathe has 32 teeth and in all images I
have seen of this lathe the gear is a 32 teeth gear. However, about half
of the entries in this column are for a 16 tooth gear. I have never seen
a 16 tooth gear that goes where the 32 teeth gear goes. I looked in the
manual I have. It never mentions a 16 tooth gear in any of its examples.
I have one gear that has two steps to it, the smaller is 16 teeth, and
the larger is 32 teeth. It has a 1/2" bore, certainly not the size to
fit on the headstock spindle. It appears from the diagrams that this is
the 16 tooth gear being talked about, but if it is, why even list it in
'Spindle Stud Gear' column because it is always the first gear that
comes in contact with the gear on the headstock spindle. Because it is
always the the first gear in contact with the headstock gear there is
nothing to change as the table implies by listing a 32 and 16 tooth gear
in this column. Could you clear up this confusion for me?
Stan
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On 2/11/2019 1:22 PM, Robert Downs via Groups.Io wrote:
Ignoring the gears for the 6¡±, which are smaller, between 1932 and
today, Atlas/Clausing made two versions of the change gears for the
9¡±, 10¡± and 12¡± lathes.? From 1932 until about 1937 they all had 3/8¡±
faces and 3/8¡± hubs and were made with tooth counts between 20T and
96T.? These all had part numbers which are also cast into the gears of
the form 9-101-nn, where ¡°nn¡± is the tooth count.? Beginning with the
Atlas 10F and the Craftsman 101.07362, 101.07382 and 101.07402, the
gears were changed to 1/2¡± hubs (everything else remaining the same)
and the cast-in part numbers became 9-101-nnA.? The bolts, sleeves,
bushings, spacers and the shafts that the screw gear mounts on all
became 1/8¡± longer.? After a few years, Atlas ceased production of the
non-A gears except for the 96T and instead you had to buy an ¡°A¡± gear
and face off 1/16¡± from each end of the hub.? After a few more years,
they quit making the 96T and they are more difficult to find than the
others.
The ¡°A¡± suffix gears were only made up through 64T because at the same
time, they introduced the 32T/16T compound gear which on the 10F is
called the Stud Gear.
The non-A gears can be installed on the 10F but it requires two 1/16¡±
thick double-keyed spacers for each gear so used.? Atlas never made
this thin spacers.? So basically, you have no use for the non-A gears
and definitely have no use for a 96T gear.
The gear charts do not specify the non-A gears.? The gear numbers in
the charts are the tooth counts, not part of the part number.
If you have a 64T gear with a hub ID larger than the double-keyed
bushings, it did not come from Atlas and does not belong with your
machine.
You also do not need a non-A 64T gear.? And the T used in some of the
documentation simply means ¡°tooth¡±. It is not part of a part number
and it does not appear on any of the Atlas made gears.? If you have a
gear that does, it did not come from Atlas but from some other make of
lathe or was made from a stock gear from some OEM like Boston. But so
long as it has a 1/2¡± hub and 3/8¡± face, it is usable on your 10F
Robert Downs
*From:*[email protected] [mailto:[email protected]]
*On Behalf Of *Stan Gorodenski
*Sent:* Sunday, February 10, 2019 23:18
*To:* [email protected]
*Subject:* [atlas-craftsman IO] Threading Gear Confusion
I am confused by the gears for my Atlas 10F lathe
Almost all my threading gears (called change gears?) have an 'A' after
the number designation, like 24A. I also have a 24. The width of the
thread is identical between the two. The only difference I can see is
that each side of the gear is very slightly wider in the 24A. Is this
the difference between a 'A' and a non-'A'? Like I said most of my
change gears are the 'A' type, but the (heavy, hinged) gear cover that
has the table of the gears needed to make a thread all specify the
non-'A' type. Since nearly all my gears are the 'A' type, do I have
another problem?
I was looking for another 64 gear, without the 'A', on the internet. I
saw one that said '64 T'. The center bore was about 5/8" but the bore of
my 64 gear is 3/4". It appears this may be the difference between a 'T'
and a non-'T', but the image of the gear did not say 64T. It said 64. If
it were not for the seller being aware of where the 64 came from, one
could buy a wrong gear. Is this an atypical situation, or is it common
for a 'T' gear to not say it is a 'T' gear on the side?
Stan
Stan Gorodenski