I am not convinced my 10F lathe originally had 16 speeds. Robert had
estimated its vintage is about 1953 or 1954. As? I mentioned in a
previous email message my lathe is a real frankenstein. I did not
realize the back gear, the bull gear, the gear attached to the spindle
pulley assembly, and the collar were all gone until many years later.
Other significant changes were made, including discarding the original
brackets for the motor.

However, I feel pretty certain my friend (who died about 3 years ago)
used the original pulleys of what I think is called the counterbalance.
Attached is an image of it. It looks original to me and you can see the
large pulley (that the belt from the motor is attached to) is just one
pulley, not two side by side. The images in the document called "Atlas
Parts list for 10"-F Series Atlas Lathes" also show the large power
pulley being just one pulley, not composed to two side by side. All this
tells me that my lathe originally came out as an 8 speed lathe, not a 16.

I don't know if the original motor was kept while it was being
frankensteinized, but the motor it has turns at 1725 RPM.

I am in the process of trying to get it back to the original 8 speed. I
ordered and am getting the back gears, the bull gear, the small spindle
gear, and the collar behind the small gear. I have the manual my friend
gave me when I bought the lathe. It is pretty beat up and I think it is
supposed to be the manual for my lathe, but it describes the 12" and 6",
not the 10". Therefore, I do not know what the maximum direct drive
spindle rpm for my lathe is supposed to be. From what I read, it is the
surface speed, not RPM of the spindle, that is important in for
machining various metals. The circumference of a 12" swing for the 12"
lathe is 37.7". For my 10" lathe it is 31.42". The 12" swing covers a
distance of 37.7" in one revolution of the spindle, but for my lathe it
only covers 31.42". Therefore, the spindle rpm for my lathe has to be
increased by 37/7/31.42. The max direct rpm for the 12" is 2072 and so
this means the direct drive rpm for my 10" has to be? 2486 for the
surface speeds to be equal between the two swings (the 12" and the 10").

2486 seems to be too fast an rpm for my 10" lathe. Is this correct"?
Stan

Surface speed for cutting is only related to rpm whether turning,
milling, drilling, grinding, whatever.
Easy to remember formula: 3.82× desired surface feet per minute ÷
diameter of whatever is rotating = rpm.
Doesn't need to be perfect, always exceptions. It's a start though.
Tool and workpiece material dictate what could work.
Dave Matticks



Sent from my T-Mobile 4G LTE Device

On 02/16/2019 04:55 PM, Stan Gorodenski wrote:

I am not convinced my 10F lathe originally had 16 speeds.
Robert had
estimated its vintage is about 1953 or 1954.

Well, all 10 and 12" Atlas and Craftsman lathes I've
encountered had basically the same setup.
A belt with 2 positions from motor to countershaft, and then
a 4-position belt from countershaft to cone pulley on the
spindle. That gives 8 speeds. Then, you have the back gear,
so now that gives 16 speeds.

Jon

Here is the badge that came with the lathe.? It should also appear in
your lathe manual.

On Sat, Feb 16, 2019 at 8:14 PM Stan Gorodenski <stanlep@...
<mailto:stanlep@...>> wrote:

On 2/16/2019 6:20 PM, David Beierl wrote:


Top speed of the 618 is about 3600 rpm.? Again, it's for
small-diameter work that you want the higher speeds.

Hmmm. I guess you are right. I was approaching it from the the other
direction. I this case there would be no reason for the max
spindle rpm
of the 10" to be higher than that of the 12". I'm not familiar
with all
this terminology - what is the 618?
Stan



Yrs,
d

The badge didn't come with the lathe I have. Maybe it got trashed
somehow over the years. The beat up manual I have that is supposed to be
for the lathe, at least I thought so, has this image, but it is for a 12".
Stan

On 2/16/2019 7:47 PM, Larry Hoelscher wrote:

Here is the badge that came with the lathe.? It should also appear in
your lathe manual.

On Sat, Feb 16, 2019 at 8:14 PM Stan Gorodenski
<stanlep@...
<mailto:stanlep@...>> wrote:

On 2/16/2019 6:20 PM, David Beierl wrote:


Top speed of the 618 is about 3600 rpm.? Again, it's for
small-diameter work that you want the higher speeds.

Hmmm. I guess you are right. I was approaching it from the the other
direction. I this case there would be no reason for the max
spindle rpm
of the 10" to be higher than that of the 12". I'm not familiar
with all
this terminology - what is the 618?
Stan



Yrs,
d

Surface speed for cutting is only related to rpm whether turning,
milling, drilling, grinding, whatever.
Easy to remember formula: 3.82× desired surface feet per minute ÷
diameter of whatever is rotating = rpm.
Doesn't need to be perfect, always exceptions. It's a start though.
Tool and workpiece material dictate what could work.
Dave Matticks



Sent from my T-Mobile 4G LTE Device

Stan, I don't see where you've mentioned the type of bearing you have
in your lathe. That can make a difference. I have what Robert tells me
is the correct manual for my TH42, with Timken bearings. On page 10,
under Bearing Adjustment, and referring to babbitt bearings, it says
to loosen the bearing cap screws between 1/8-1/4 turn for speeds over
805rpm. When you're going back to lower speeds, or heavier cuts,
you're supposed to tighten them again to maintain the correct bearing
clearances. Next page says the Timken bearings are recommended for
high spindle speeds for long intervals or for continuous production
work with no adjustment. Page 47, on the machining of various
materials, has a chart that shows 8 speeds of 164-2072rpm in direct
drive depending on the pulley steps, and exclusive of the back gear.
Back gear gives 8 steps from 28-345rpm.

I have a pdf copy of the MOLO for the the Sears Master Craftsman
lathe. It's different from the one for my TH42 in some places, but the
info on page 10 is nearly identical. It doesn't have the chart on page
47, but a different spindle speed chart is on page 49 in both books,
and lists the minimum and maximum speeds as 28 & 2072rpm. I think I'd
figure 2072rpm as the max speed for either 10 or 12 inch lathes

HTH!

Bill in OKC

On Saturday, February 16, 2019, 6:41:56 PM CST, Stan Gorodenski
<stanlep@...> wrote:


I think we all agree because I did take into account surface speed if
you read my email. I am assuming the max rpm was set by Atlas to
whatever it is by some considerations that have to do with possible
surface speeds one might encounter. I don't think they just randomly
selected a max rpm. Therefore, if Atlas had determined, which seems
reasonable, that the max rpm for the 12" lathe is related to the max
surface speed one might need, then to get an equivalent rpm for the 10"
should be what I had suggested.

However, aside from an argument of how to determine surface speed or
equate rpm to surface speed, the main point of my post was to find out
what the max rpm, as it came from the factory, is for my lathe. It had
to have come out with this max rpm, whatever it may have been, for a
reason. So, what was the max rpm as it came out from the factory? Does
anyone know? 2486 seems too high to me.

Also, can anyone confirm that the number of speeds for my lathe was 8 as
it came from the factory, not 16? I think it was 8 based on what I said
in my previous post and the image I had attached.
Stan

On 2/16/2019 5:22 PM, Dave Matticks wrote:

Surface speed for cutting is only related to rpm whether turning,
milling, drilling, grinding, whatever.
Easy to remember formula: 3.82× desired surface feet per minute ÷
diameter of whatever is rotating = rpm.
Doesn't need to be perfect, always exceptions. It's a start though.
Tool and workpiece material dictate what could work.
Dave Matticks



Sent from my T-Mobile 4G LTE Device

The badge didn't come with the lathe I have. Maybe it got trashed
somehow over the years. The beat up manual I have that is supposed to be
for the lathe, at least I thought so, has this image, but it is for a 12".
Stan

On 2/16/2019 7:47 PM, Larry Hoelscher wrote:

Here is the badge that came with the lathe.? It should also appear in
your lathe manual.

On Sat, Feb 16, 2019 at 8:14 PM Stan Gorodenski
<stanlep@...
<mailto:stanlep@...>> wrote:

On 2/16/2019 6:20 PM, David Beierl wrote:


Top speed of the 618 is about 3600 rpm.? Again, it's for
small-diameter work that you want the higher speeds.

Hmmm. I guess you are right. I was approaching it from the the other
direction. I this case there would be no reason for the max
spindle rpm
of the 10" to be higher than that of the 12". I'm not familiar
with all
this terminology - what is the 618?
Stan



Yrs,
d

Stan, I don't see where you've mentioned the type of bearing you have
in your lathe. That can make a difference. I have what Robert tells me
is the correct manual for my TH42, with Timken bearings. On page 10,
under Bearing Adjustment, and referring to babbitt bearings, it says
to loosen the bearing cap screws between 1/8-1/4 turn for speeds over
805rpm. When you're going back to lower speeds, or heavier cuts,
you're supposed to tighten them again to maintain the correct bearing
clearances. Next page says the Timken bearings are recommended for
high spindle speeds for long intervals or for continuous production
work with no adjustment. Page 47, on the machining of various
materials, has a chart that shows 8 speeds of 164-2072rpm in direct
drive depending on the pulley steps, and exclusive of the back gear.
Back gear gives 8 steps from 28-345rpm.

I have a pdf copy of the MOLO for the the Sears Master Craftsman
lathe. It's different from the one for my TH42 in some places, but the
info on page 10 is nearly identical. It doesn't have the chart on page
47, but a different spindle speed chart is on page 49 in both books,
and lists the minimum and maximum speeds as 28 & 2072rpm. I think I'd
figure 2072rpm as the max speed for either 10 or 12 inch lathes

HTH!

Bill in OKC

On Saturday, February 16, 2019, 6:41:56 PM CST, Stan Gorodenski
<stanlep@...> wrote:


I think we all agree because I did take into account surface speed if
you read my email. I am assuming the max rpm was set by Atlas to
whatever it is by some considerations that have to do with possible
surface speeds one might encounter. I don't think they just randomly
selected a max rpm. Therefore, if Atlas had determined, which seems
reasonable, that the max rpm for the 12" lathe is related to the max
surface speed one might need, then to get an equivalent rpm for the 10"
should be what I had suggested.

However, aside from an argument of how to determine surface speed or
equate rpm to surface speed, the main point of my post was to find out
what the max rpm, as it came from the factory, is for my lathe. It had
to have come out with this max rpm, whatever it may have been, for a
reason. So, what was the max rpm as it came out from the factory? Does
anyone know? 2486 seems too high to me.

Also, can anyone confirm that the number of speeds for my lathe was 8 as
it came from the factory, not 16? I think it was 8 based on what I said
in my previous post and the image I had attached.
Stan

On 2/16/2019 5:22 PM, Dave Matticks wrote:

Surface speed for cutting is only related to rpm whether turning,
milling, drilling, grinding, whatever.
Easy to remember formula: 3.82× desired surface feet per minute ÷
diameter of whatever is rotating = rpm.
Doesn't need to be perfect, always exceptions. It's a start though.
Tool and workpiece material dictate what could work.
Dave Matticks



Sent from my T-Mobile 4G LTE Device

From: [email protected] [mailto:[email protected]] On Behalf Of Stan Gorodenski
Sent: 17 February 2019 01:14 AM
To: [email protected]
Subject: Re: [atlas-craftsman IO] Not Convinced

?

Forgot to attach. Here it is.

On 2/16/2019 3:55 PM, Stan Gorodenski wrote:

I am not convinced my 10F lathe originally had 16 speeds. Robert had
estimated its vintage is about 1953 or 1954. As? I mentioned in a
previous email message my lathe is a real frankenstein. I did not
realize the back gear, the bull gear, the gear attached to the spindle
pulley assembly, and the collar were all gone until many years later.
Other significant changes were made, including discarding the original
brackets for the motor.

However, I feel pretty certain my friend (who died about 3 years ago)
used the original pulleys of what I think is called the counterbalance.
Attached is an image of it. It looks original to me and you can see the
large pulley (that the belt from the motor is attached to) is just one
pulley, not two side by side. The images in the document called "Atlas
Parts list for 10"-F Series Atlas Lathes" also show the large power
pulley being just one pulley, not composed to two side by side. All this
tells me that my lathe originally came out as an 8 speed lathe, not a 16.

I don't know if the original motor was kept while it was being
frankensteinized, but the motor it has turns at 1725 RPM.

I am in the process of trying to get it back to the original 8 speed. I
ordered and am getting the back gears, the bull gear, the small spindle
gear, and the collar behind the small gear. I have the manual my friend
gave me when I bought the lathe. It is pretty beat up and I think it is
supposed to be the manual for my lathe, but it describes the 12" and 6",
not the 10". Therefore, I do not know what the maximum direct drive
spindle rpm for my lathe is supposed to be. From what I read, it is the
surface speed, not RPM of the spindle, that is important in for
machining various metals. The circumference of a 12" swing for the 12"
lathe is 37.7". For my 10" lathe it is 31.42". The 12" swing covers a
distance of 37.7" in one revolution of the spindle, but for my lathe it
only covers 31.42". Therefore, the spindle rpm for my lathe has to be
increased by 37/7/31.42. The max direct rpm for the 12" is 2072 and so
this means the direct drive rpm for my 10" has to be? 2486 for the
surface speeds to be equal between the two swings (the 12" and the 10").

2486 seems to be too fast an rpm for my 10" lathe. Is this correct"?
Stan

?

Forgot to attach. Here it is.

On 2/16/2019 3:55 PM, Stan Gorodenski wrote:

I am not convinced my 10F lathe originally had 16 speeds. Robert had
estimated its vintage is about 1953 or 1954. As? I mentioned in a
previous email message my lathe is a real frankenstein. I did not
realize the back gear, the bull gear, the gear attached to the spindle
pulley assembly, and the collar were all gone until many years later.
Other significant changes were made, including discarding the original
brackets for the motor.

However, I feel pretty certain my friend (who died about 3 years ago)
used the original pulleys of what I think is called the counterbalance.
Attached is an image of it. It looks original to me and you can see the
large pulley (that the belt from the motor is attached to) is just one
pulley, not two side by side. The images in the document called "Atlas
Parts list for 10"-F Series Atlas Lathes" also show the large power
pulley being just one pulley, not composed to two side by side. All this
tells me that my lathe originally came out as an 8 speed lathe, not a 16.

I don't know if the original motor was kept while it was being
frankensteinized, but the motor it has turns at 1725 RPM.

I am in the process of trying to get it back to the original 8 speed. I
ordered and am getting the back gears, the bull gear, the small spindle
gear, and the collar behind the small gear. I have the manual my friend
gave me when I bought the lathe. It is pretty beat up and I think it is
supposed to be the manual for my lathe, but it describes the 12" and 6",
not the 10". Therefore, I do not know what the maximum direct drive
spindle rpm for my lathe is supposed to be. From what I read, it is the
surface speed, not RPM of the spindle, that is important in for
machining various metals. The circumference of a 12" swing for the 12"
lathe is 37.7". For my 10" lathe it is 31.42". The 12" swing covers a
distance of 37.7" in one revolution of the spindle, but for my lathe it
only covers 31.42". Therefore, the spindle rpm for my lathe has to be
increased by 37/7/31.42. The max direct rpm for the 12" is 2072 and so
this means the direct drive rpm for my 10" has to be? 2486 for the
surface speeds to be equal between the two swings (the 12" and the 10")

2486 seems to be too fast an rpm for my 10" lathe. Is this correct"?
Stan