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
Stan Gorodenski