Very nice post, Don! I would add only one thing. When cleaning off the
surface rust, make full strokes of the (whatever) abrasive, as opposed to
short strokes only in the problem areas. You want to distribute "new" wear
evenly over the way surfaces.
Bob Swinney
"DoN. Nichols" wrote in message
...
In article ,
PeterM wrote:
I just picked up an older Unimat lathe, a DB 200.
That's even older than my SL-1000 -- but very similar. IIRC, it
has iron castings for the base, instead of aluminum ones, and there is a
slight difference in how the headstock attaches to either the base or
the milling column, but otherwise quite similar.
I like to clean it up.
It
has light rust on the metal rails that allow other pieces to slide on.
What
is the best way to do that,
What I would do in that case is to remove the rails from the
base casting (one screw at each end per rail), and then spray it with
something like WD-40 and rub one of the finer grades of 3M's
ScotchBrite, or a very fine steel wool to clean off the light rust.
(Note that the WD-40 is useless for preventing the rust from occuring,
but nice enough for the cleaning.)
It should not make a difference, but I would still mark each rod
at the end, so it goes back in the same place and the same orientation
-- perhaps by making a single center punch mark at the right-hand end of
the front rod, and a double mark at the right-hand end of the rear rod.
If the rods are badly pitted, you should be able to get some
drill rod of the same size (12mm I think?). In the UK, drill rod would
be called "Silver Steel". Actually, the metric size will probably be
easier to find in the UK than here in the USA. I don't think that you
will need to harden the rods -- the originals never seemed to be
hardened.
and maybe a hint on what to put on the parts
afterwards, so the rust will not come back......many
thanks...........Peter
I would use a good waylube (e.g. Vactra No. 2 Waylube) to keep
it lubed and free of moisture. If all you have is a Unimat, the minimum
purchase of a gallon should keep you going for life. Perhaps you should
find a hobby machinist near wherever you live, and offer to buy a pint
from him. (I know that I ordered a 5 gallon container of the Vactra No.
2, and use it on several machines.)
Remember -- after using the machine, clean off the rails, and
once clean, re-lube with the Vactra No. 2 again.
Note that this is far from the most rigid design for the size --
those rods flex visibly under all but the lightest cuts. But you can
learn a lot about how to deal with the limitations of a lathe using that
machine.
WD-40 makes a good lubricant/coolant for machining aluminum, but
is more likely to concentrate water from the air and encourage rust if
left on the surface. Vactra No. 2 stays there forever. But it will
accumulate chips and such, which is why you want to clean the rods after
use (and WD-40 is good for that, at least). Then you dry the WD-40 off,
and coat with the Vactra No. 2.
Good Luck,
DoN.
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