Al MacDonald wrote:
Greetings,

Thinking about lathes and wondered what feedback I could get by asking the
question "what do you think is one of the best lathes"? I'm especially
interested in the reasons. I've owned a SB 10k for a number of years and
found it to be a good lathe.... great size, robust and well built, quite
accurate, and was supported with a good range of accessories (if I could
afford them!). Recently I got an incredible deal on a Summit lathe so now I
have something to compare, and the weak points of the SB start to show.
Well, I got my own deal, on a totally top of the line Sheldon R15.
It has a 2.25" spindle through hole, and D1-6 spindle mount.
I don't have a clutch, but I did rig a jog button, as my VFD has
that function. It is real nice when the gears or direct-drive dog
doesn't want to engage. I did have to rebuild the bed ways, but overall
it was worth it. Every time something needs turning, now, I get a BIG
grin on my face!

Recently I've been thinking about the refacing of a faceplate when
rebuilding an old Willson 16" swing lathe. Surface cutting speeds vary
hugely between the inside and outside of the surface, to the point where
there is no correct RPM setting that will work at both ends, and it showed
in the finish. One book I read suggested stopping part way through and
changing spindle speeds, but I'm sure that would leave a mark also. Ding!
What a person needs is a variable speed arrangement and a spindle tach. ...
maybe I could modify the SB. Yes, a VFD on a 3phase motor would work, but
they do tend to make a noise that might drive me crazy. Ok, how about some
variable pulley system like the kind used on the medium sized drill presses?
Maybe. Oh, and a clutch. How about modifying a clutch off the end of an
industrial sewing machine motor? Possibly. I think I'm driving myself
crazy.
I don't know what "noise" you are talking about. Maybe old VFDs from
the early 1980's made singing noises (we still have a bunch of them in
the mechanical rooms at work) but most of the new ones (by that I mean
since 1985 or so) don't make audible noise, either from the VFD or the
motor they power. The 11 KW unit on my Sheldon has fans in it that
run for a minute after you stop the spindle. You can't hear the fans
when the spindle motor is on. The 1 Hp VFD on my mill has no fans, and
it makes a TINY singing noise that I can hear when the spindle is in the
DC injection braking part of the cycle. But, that is so tiny a sound,
it is no problem, and can only be heard as the spindle comes to a
complete stop. So, I think the audible noise problem is only on VERY
old units. Otherwise, I REALLY like the VFDs, and wouldn't have
anything else. I really don't need a clutch with the VFD. I can run
forward or reverse, jog and vary the speed while it is running.


A 10" SB with roller bearings on the spindle, variable speed, camlock and
clutch, would be a great machine. Is there anything out there like this or
am I dreaming?
Umm, well, I think my Sheldon R15-6 fills all these requirements. They
are a bit rare, but REALLY well made. 3500 Lbs, though, so it certainly
is NOT in the same class as the SB 10. Unlike old 15" lathes, the
standard model goes to 1250 RPM, the "high speed" model uses a 2-speed
motor to get to 2500 RPM. (Hmm, I can't imagine taking my 8.25"
Phase-II chuck to 2500 RPM!) I can do 2500 RPM with the VFD even though
I DON'T have the high-speed option on mine.

Jon