Re: [CAD_CAM_EDM_DRO] New Lathe

Smoke wrote:

> How big is your lathe? At 3000 lb. it certainly can't be a 15" machine.

It possibly may be as 'light' as 2500 Lbs., I don't have documents
that verify the weight. I have no problem believing it weighs 3000 Lbs,
however. It did a great job of tipping a 21,000 Lb reach forklift, which
I needed to do to get the tires up out of the holes they had sunk into.
The Sheldon 15" x 42" is a HEAVILY built lathe, probably close to
Cadillac or Mori-Seiki quality (generally considered to be the absolute
top of the line quality). There are heavier 15" lathes. LeBlond toolroom
lathes are massively constructed, at least as heavy as my Sheldon.
The headstock casting is literally the size of a V6 engine block!
I had to buy an engine hoist to lift the headstock off the bed. I'm
glad I didn't make the mistake of trying to move it with jury-rigged
methods, or I might be writing this from a hospital bed. The tailstock
is so heavy I can't lift it by myself! A good friend of mine helped me
remove it, and it was very heavy for the two of us! Note this lathe
has the D1-6 spindle nose, Morse # 4 tailstock taper, and 5 Hp motor.
The apron weighs about 80 Lbs, and the bare carriage without the crossslide
weighs about 60 Lbs. The crossslide weighs 60 Lbs, too. The complete
compound rest weighs about 50 Lbs. This is no Atlas lathe, I'll tell
you that!

> Personally, I'd say the lathe has some inherent faults based on your
> information.
>
> Heat treatment of the ways must be poor quality, otherwise is wouldn't wear
> rapidly as you indicate.

Umm, it didn't wear 'rapidly'. This was obviously a production lathe
somewhere
for many of its last 29 years. And, it doesn't appear that it was treated
with
great care. I found chips jammed into the bottom of the carriage, where the
oil distribution manifold is. There is only one way this could have happened.

That is by ramming the carriage through mountains of swarf piled between
the bed ways. (Yuck!) This, I think, clearly indicates the production
and hard use the machine has sustained. There are little chips and dings
in the bed. Many of these were filled with brass or bronze chips, which
then got embedded into the carriage slides, and then ground into the
bed.

> Either the material used for the base or the design of the casting is poor
> quality...or both. Otherwise you shouldn't be getting the deflection you
> mention.

Deflection? No, I think proper leveling is even more important with the
big lathes than on smaller machines. I did note that with the tailstock
end on a roller, so it could twist whichever way the bed wanted it, the bed
was DEAD straight! That was a good indication that the bed was not
warped in any way. I also noted that the bed remained DEAD straight
as I removed about 1000 Lbs of accessories from the lathe. This is
a good indication that the bed is completely adequate for this machine.
On an Atlas, with a master precision level, you can watch the bed sag
and sway as you move the carriage back and forth! I can stand on
this bed without any deflection measurable with the MPL.

Jon