?

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

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

?

?

--

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.

?

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

?

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

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,

Each gear that can be mounted on the change gear bracket (AKA Banjo),
plus the Screw Gear which is the one in line with the lead screw, can
be mounted in either of two positions called F for Front (nearest the
operator) and B for Back (nearest the headstock or lead screw).? This
is true of the 10F models and all 12” models.? The first gear on the
Banjo when mounted in the B position meshes with the 32T part of the
Stud Gear.? When mounted in the F position, it meshes with the 16T
part of the stud gear. Which gives a 2:1 speed reduction.? Why they on
the threading charts called the Stud Gear the Spindle Stud Gear I have
no idea.? On the 10” it is driven by the 32T spindle gear.? On the 12”
charts it is called the Compound Tumbler Gear.

Robert Downs

*From:*[email protected] [mailto:[email protected]]
*On Behalf Of *Stan Gorodenski
*Sent:* Tuesday, February 12, 2019 11:24
*To:* [email protected]
*Subject:* Re: [atlas-craftsman IO] Threading Gear Confusion

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

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

?

This is still all confusing, but I think it correctly dawned on me how
the double (compound?) gear that consists of two gears, a 32 and a 16 is
mounted on the 1/2" diameter shaft. Looking at the diagrams and table on
the heavy cast iron cover, it appears the 32 face, larger in diameter
than the 16 face, must be mounted closest to the headstock. The diagram
does not show a dotted or dashed circle to represent the 16 face and so
it must face away from the headstock. I think I now understand why they
list 16 in the "Spindle Stud Gear". I think they are just relating this
to the figures on the cast iron cover. So, it means there is no 16 tooth
gear on the tail end of the headstock spindle. It is the 16 tooth on the
double gear. My description may not be good. I could attach images, but
I think I understand it now.
Stan

On 2/12/2019 11:43 AM, Robert Downs via Groups.Io wrote:

Stan,

Each gear that can be mounted on the change gear bracket (AKA Banjo),
plus the Screw Gear which is the one in line with the lead screw, can
be mounted in either of two positions called F for Front (nearest the
operator) and B for Back (nearest the headstock or lead screw).? This
is true of the 10F models and all 12” models.? The first gear on the
Banjo when mounted in the B position meshes with the 32T part of the
Stud Gear.? When mounted in the F position, it meshes with the 16T
part of the stud gear. Which gives a 2:1 speed reduction.? Why they on
the threading charts called the Stud Gear the Spindle Stud Gear I have
no idea.? On the 10” it is driven by the 32T spindle gear.? On the 12”
charts it is called the Compound Tumbler Gear.

Robert Downs

*From:*[email protected] [mailto:[email protected]]
*On Behalf Of *Stan Gorodenski
*Sent:* Tuesday, February 12, 2019 11:24
*To:* [email protected]
*Subject:* Re: [atlas-craftsman IO] Threading Gear Confusion

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

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

From: [email protected] [mailto:[email protected]] On Behalf Of Stan Gorodenski
Sent: 12 February 2019 09:34 PM
To: [email protected]
Subject: Re: [atlas-craftsman IO] Threading Gear Confusion

?

This is still all confusing, but I think it correctly dawned on me how
the double (compound?) gear that consists of two gears, a 32 and a 16 is
mounted on the 1/2" diameter shaft. Looking at the diagrams and table on
the heavy cast iron cover, it appears the 32 face, larger in diameter
than the 16 face, must be mounted closest to the headstock. The diagram
does not show a dotted or dashed circle to represent the 16 face and so
it must face away from the headstock. I think I now understand why they
list 16 in the "Spindle Stud Gear". I think they are just relating this
to the figures on the cast iron cover. So, it means there is no 16 tooth
gear on the tail end of the headstock spindle. It is the 16 tooth on the
double gear. My description may not be good. I could attach images, but
I think I understand it now.
Stan

On 2/12/2019 11:43 AM, Robert Downs via Groups.Io wrote:

Stan,

Each gear that can be mounted on the change gear bracket (AKA Banjo),
plus the Screw Gear which is the one in line with the lead screw, can
be mounted in either of two positions called F for Front (nearest the
operator) and B for Back (nearest the headstock or lead screw).? This
is true of the 10F models and all 12” models.? The first gear on the
Banjo when mounted in the B position meshes with the 32T part of the
Stud Gear.? When mounted in the F position, it meshes with the 16T
part of the stud gear. Which gives a 2:1 speed reduction.? Why they on
the threading charts called the Stud Gear the Spindle Stud Gear I have
no idea.? On the 10” it is driven by the 32T spindle gear.? On the 12”
charts it is called the Compound Tumbler Gear.

Robert Downs

*From:*[email protected] [mailto:[email protected]]
*On Behalf Of *Stan Gorodenski
*Sent:* Tuesday, February 12, 2019 11:24
*To:* [email protected]
*Subject:* Re: [atlas-craftsman IO] Threading Gear Confusion

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

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 ,

?

Does this help ?

?

The “spindle” 32T gear is quite long , and can accommodate the 32/16T combination gear being mounted either way , either as a reduction or as an idler ?,

?

Regards,

?

Carvel

?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Stan Gorodenski
Sent: 12 February 2019 09:34 PM
To: [email protected]
Subject: Re: [atlas-craftsman IO] Threading Gear Confusion

?

This is still all confusing, but I think it correctly dawned on me how
the double (compound?) gear that consists of two gears, a 32 and a 16 is
mounted on the 1/2" diameter shaft. Looking at the diagrams and table on
the heavy cast iron cover, it appears the 32 face, larger in diameter
than the 16 face, must be mounted closest to the headstock. The diagram
does not show a dotted or dashed circle to represent the 16 face and so
it must face away from the headstock. I think I now understand why they
list 16 in the "Spindle Stud Gear". I think they are just relating this
to the figures on the cast iron cover. So, it means there is no 16 tooth
gear on the tail end of the headstock spindle. It is the 16 tooth on the
double gear. My description may not be good. I could attach images, but
I think I understand it now.
Stan

On 2/12/2019 11:43 AM, Robert Downs via Groups.Io wrote:

Stan,

Each gear that can be mounted on the change gear bracket (AKA Banjo),
plus the Screw Gear which is the one in line with the lead screw, can
be mounted in either of two positions called F for Front (nearest the
operator) and B for Back (nearest the headstock or lead screw).? This
is true of the 10F models and all 12” models.? The first gear on the
Banjo when mounted in the B position meshes with the 32T part of the
Stud Gear.? When mounted in the F position, it meshes with the 16T
part of the stud gear. Which gives a 2:1 speed reduction.? Why they on
the threading charts called the Stud Gear the Spindle Stud Gear I have
no idea.? On the 10” it is driven by the 32T spindle gear.? On the 12”
charts it is called the Compound Tumbler Gear.

Robert Downs

*From:*[email protected] [mailto:[email protected]]
*On Behalf Of *Stan Gorodenski
*Sent:* Tuesday, February 12, 2019 11:24
*To:* [email protected]
*Subject:* Re: [atlas-craftsman IO] Threading Gear Confusion

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

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 ,

Does this help ?

The “spindle” 32T gear is quite long , and can accommodate the 32/16T
combination gear being mounted either way , either as a reduction or
as an idler ?,

Regards,

Carvel

*From:*[email protected] [mailto:[email protected]]
*On Behalf Of *Stan Gorodenski
*Sent:* 12 February 2019 09:34 PM
*To:* [email protected]
*Subject:* Re: [atlas-craftsman IO] Threading Gear Confusion

This is still all confusing, but I think it correctly dawned on me how
the double (compound?) gear that consists of two gears, a 32 and a 16 is
mounted on the 1/2" diameter shaft. Looking at the diagrams and table on
the heavy cast iron cover, it appears the 32 face, larger in diameter
than the 16 face, must be mounted closest to the headstock. The diagram
does not show a dotted or dashed circle to represent the 16 face and so
it must face away from the headstock. I think I now understand why they
list 16 in the "Spindle Stud Gear". I think they are just relating this
to the figures on the cast iron cover. So, it means there is no 16 tooth
gear on the tail end of the headstock spindle. It is the 16 tooth on the
double gear. My description may not be good. I could attach images, but
I think I understand it now.
Stan

On 2/12/2019 11:43 AM, Robert Downs via Groups.Io wrote:


Stan,

Each gear that can be mounted on the change gear bracket (AKA Banjo),
plus the Screw Gear which is the one in line with the lead screw, can
be mounted in either of two positions called F for Front (nearest the
operator) and B for Back (nearest the headstock or lead screw).? This
is true of the 10F models and all 12” models.? The first gear on the
Banjo when mounted in the B position meshes with the 32T part of the
Stud Gear.? When mounted in the F position, it meshes with the 16T
part of the stud gear. Which gives a 2:1 speed reduction.? Why they on
the threading charts called the Stud Gear the Spindle Stud Gear I have
no idea.? On the 10” it is driven by the 32T spindle gear.? On the 12”
charts it is called the Compound Tumbler Gear.

Robert Downs

*From:*[email protected] [mailto:[email protected]]
*On Behalf Of *Stan Gorodenski
*Sent:* Tuesday, February 12, 2019 11:24
*To:* [email protected]
*Subject:* Re: [atlas-craftsman IO] Threading Gear Confusion

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

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

?

The photo should explain things.? Thanks.

?

However, the 32T Spindle gear being as long as it is, is a holdover from the 9” and the 10 through 10E.? Sometimes the chart calls for the gear in the “A” position to be in the F position and sometimes in the B.? So it was necessary for the spindle gear to handle either case.? With the 10F, the compound Stud Gear is always mounted as shown in your photo, with the 32T gear in the B position and the 16T in F.? If Atlas had thought like GM and Ford and all of today’s computer builders, they would have changed the spindle gear and the length of the spindle to save a nickel.? :-)

?

?

?

Stan ,

?

Does this help ?

?

The “spindle” 32T gear is quite long , and can accommodate the 32/16T combination gear being mounted either way , either as a reduction or as an idler ?,

?

Regards,

?

Carvel

?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Stan Gorodenski
Sent: 12 February 2019 09:34 PM
To: [email protected]
Subject: Re: [atlas-craftsman IO] Threading Gear Confusion

?

This is still all confusing, but I think it correctly dawned on me how
the double (compound?) gear that consists of two gears, a 32 and a 16 is
mounted on the 1/2" diameter shaft. Looking at the diagrams and table on
the heavy cast iron cover, it appears the 32 face, larger in diameter
than the 16 face, must be mounted closest to the headstock. The diagram
does not show a dotted or dashed circle to represent the 16 face and so
it must face away from the headstock. I think I now understand why they
list 16 in the "Spindle Stud Gear". I think they are just relating this
to the figures on the cast iron cover. So, it means there is no 16 tooth
gear on the tail end of the headstock spindle. It is the 16 tooth on the
double gear. My description may not be good. I could attach images, but
I think I understand it now.
Stan

On 2/12/2019 11:43 AM, Robert Downs via Groups.Io wrote:

Stan,

Each gear that can be mounted on the change gear bracket (AKA Banjo),
plus the Screw Gear which is the one in line with the lead screw, can
be mounted in either of two positions called F for Front (nearest the
operator) and B for Back (nearest the headstock or lead screw).? This
is true of the 10F models and all 12” models.? The first gear on the
Banjo when mounted in the B position meshes with the 32T part of the
Stud Gear.? When mounted in the F position, it meshes with the 16T
part of the stud gear. Which gives a 2:1 speed reduction.? Why they on
the threading charts called the Stud Gear the Spindle Stud Gear I have
no idea.? On the 10” it is driven by the 32T spindle gear.? On the 12”
charts it is called the Compound Tumbler Gear.

Robert Downs

*From:*[email protected] [mailto:[email protected]]
*On Behalf Of *Stan Gorodenski
*Sent:* Tuesday, February 12, 2019 11:24
*To:* [email protected]
*Subject:* Re: [atlas-craftsman IO] Threading Gear Confusion

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

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

?

Robert – thanks for the correction

I was confusing things with the “sliding gear” on my QCGB version ,

?

Keep well,

?

Carvel

?

?

The photo should explain things.? Thanks.

?

However, the 32T Spindle gear being as long as it is, is a holdover from the 9” and the 10 through 10E.? Sometimes the chart calls for the gear in the “A” position to be in the F position and sometimes in the B.? So it was necessary for the spindle gear to handle either case.? With the 10F, the compound Stud Gear is always mounted as shown in your photo, with the 32T gear in the B position and the 16T in F.? If Atlas had thought like GM and Ford and all of today’s computer builders, they would have changed the spindle gear and the length of the spindle to save a nickel.? :-)

?

?

?

Stan ,

?

Does this help ?

?

The “spindle” 32T gear is quite long , and can accommodate the 32/16T combination gear being mounted either way , either as a reduction or as an idler ?,

?

Regards,

?

Carvel

?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Stan Gorodenski
Sent: 12 February 2019 09:34 PM
To: [email protected]
Subject: Re: [atlas-craftsman IO] Threading Gear Confusion

?

This is still all confusing, but I think it correctly dawned on me how
the double (compound?) gear that consists of two gears, a 32 and a 16 is
mounted on the 1/2" diameter shaft. Looking at the diagrams and table on
the heavy cast iron cover, it appears the 32 face, larger in diameter
than the 16 face, must be mounted closest to the headstock. The diagram
does not show a dotted or dashed circle to represent the 16 face and so
it must face away from the headstock. I think I now understand why they
list 16 in the "Spindle Stud Gear". I think they are just relating this
to the figures on the cast iron cover. So, it means there is no 16 tooth
gear on the tail end of the headstock spindle. It is the 16 tooth on the
double gear. My description may not be good. I could attach images, but
I think I understand it now.
Stan

On 2/12/2019 11:43 AM, Robert Downs via Groups.Io wrote:

Stan,

Each gear that can be mounted on the change gear bracket (AKA Banjo),
plus the Screw Gear which is the one in line with the lead screw, can
be mounted in either of two positions called F for Front (nearest the
operator) and B for Back (nearest the headstock or lead screw).? This
is true of the 10F models and all 12” models.? The first gear on the
Banjo when mounted in the B position meshes with the 32T part of the
Stud Gear.? When mounted in the F position, it meshes with the 16T
part of the stud gear. Which gives a 2:1 speed reduction.? Why they on
the threading charts called the Stud Gear the Spindle Stud Gear I have
no idea.? On the 10” it is driven by the 32T spindle gear? On the 12”
charts it is called the Compound Tumbler Gear.

Robert Downs

*From:*[email protected] [mailto:[email protected]]
*On Behalf Of *Stan Gorodenski
*Sent:* Tuesday, February 12, 2019 11:24
*To:* [email protected]
*Subject:* Re: [atlas-craftsman IO] Threading Gear Confusion

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

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