Not to go off and get all weird, but...
I think the reason I have so many lathes
is that each lathe operates with a different feel,
a different operator interaction experience.
The feel of the knobs, the friction or freedom
of the cross slide and carriage... All make a
difference. Even if the bats on the handles are
rotating or non-rotating make a difference in feel
and user interaction.
Then there is basic elements and human interaction.
On the Hardinge HLV-H, the tailstock is a real pain
to move. It is as difficult to move as the big heavy
TS on my Colchester 17". But my Pratt Whitney 12C
lathe has spring loaded ball bearings that lift the TS
from the bottom when you unlock it, and it is like a
cloud to move on the bed.
Some of my lathes have a more (or less) repeatable
power feed cut of mechanism, some repeat within
one thousandth and others within maybe a few
thousandths. Some have power feed clutches that
are friction slide, some are face tooth engagement
whole other are sliding gear engagement.
That makes a difference, because if you get the
power feed in a jamb (heavy cut that hit a shoulder)
then some disengage easily, where some will jamb in
feed mode, and you have a crash because you can't
shut off the feed when loaded.
One thing I value most of all, is a quiet lathe.
My Hendey was a motor-generator (like a Monarch)
and with the cooling fan and the 3600 rpm motor,
the whole thing is super loud, even before you turn
on the spindle motor. A 3 phase motor and VFD
retrofit is in it's future to make it more quiet.
And physical attractiveness of a lathes is a factor too.
A rectangular block headstock lathes is as unattractive
as a rectangular block shaped woman. Lathes built
in an era where artistic shape and fluid form was
important are very appealing to run. It has been
observed that, if two machines exist, and perform
the same, and one is on the list to be sold or scrapped,
the better looking machines gets saved and the block
head, plain Jane looking machine gets sold or scrapped.
Shape matters to human emotion of the person running
the machine. Otherwise all cars would look the same.
So I surround myself with sexy machines.
Chuck mounts can be a factor too. A chuck will never
come off (by accident) a Lodge (L-0, L-1, L-2) taper.
I have seen D series camlock spindles spit off a chuck
when someone carelessly started up a lathe, and the soft jaw hit the saddle wing. (saved it from damage,
really). I might be in the minority in saying the A series
of bolt on chucks are a good solution. They have the
short taper of the D series, but bolts instead of cams,
so it is positively retained. Me personally I don't mind
un-doing 3 bolts. I do more than that to flip the soft
jaws around anyways.
I try to like lathes with a fill length cross slide. Many lathes have a 2/3rds length cross slide compared to
the ways on the saddle. More bearing surface,
more better. And speaking of that, some lathes have a really funky taper attachment. The lock-out mechanisms to give control of the feedscrew back to
the handwheel and dial can be problematic also.
My P&W lathe has a telescopic feedscrew, and there
is are splines between the end of the screw and the
feed handle. There is a bit of angular looseness
to the splines, and the reading divisions on the dial
float around a bit. Not good for tapping a few tenths
on the dial with your finger knuckle.
Then there are taper gib lathes and there are set screw
adjusted gib lathes. Obviously taper gibs have stiffness
advantages. Then there are gibs in the middle. My `
17" Colchester has set screw adjusted gibs, but they
also have hold down screws to lock them in position.
Kind of a neat arrangement.
Then there is bed construction. The dovetail bed of the
HLV-H has an inherent flaw of crabbing severely when
it gains wear. This is because the drive pinion in the
front of the carriage ends up transmitting force
diagonally across to the rear corner of the saddle
before linear movement can take place. Beds with
inverted vee ways have a more acute and shorter
diagonal to transmit the force before saddle movement
takes place. Less crab. Some lathes have a vee and a
flat way for the bed, and some have two vee's. Two
vee's is old school and many see as better, but when
they wear, the carriage drops and crabs like a
dovetail bed. I still like the single vee and flat.
Some of the better lathes have self oiling slideways. Some have pumps run by cranking the cross slide, some have pumps run of the power feed rod, and
some have pumps cycle every time you actuate the
clutch/brake lever. Just a note, I have work on 3 of
machines that has mis-drilled oil passages, that
did not pass oil. Always scrutinize your oil system.
If the machine has Bijur oil metering units, assume
they are clogged, and test or replace them.
Just some points of a lathe to consider.
I hope it helps you select a good one.
-Doozer
