Buying the Mill - Milling - page 51

How to set up the milling machine and check for accuracy
The milling machine is fairly easy to set up accurately as it normally has a
self-contained base that everything bolts onto. The milling machine's base will
usually be bolted down to the milling machine's cabinet stand or bolted direc-
tly onto the workbench.
The normal hobby milling machine will have a round or dovetailed column
that bolts onto the milling machine's base. It is important that this column is
truly vertical. To check this verticality we will have to completely assemble the
milling machine and check it for accuracy.
If you have purchased a new machine, you need to put a dial test indicator
into the machine's spindle and check the table is flat as described previously
for checking a second-hand machine. If this check finds that the table is not
parallel, there will be no alternative but to get it collected by the manufacturer
and a replacement milling machine delivered.
While it is important that the milling machine's spindle is square to the table,
this can be sorted out on assembly, by scraping either the column mounting
face or the base of the column mounting face. An alternative is to use some
thin shim, paper often being enough to do the correction.
If the milling machine has a round column, a piece of round bar can be ma-
chined in the lathe and the column mounting casting machined true by clamp-
ing it on this diameter. Do support this mandrel with a running centre as the
casting may be stuck well out. You may still have to scrape or shim the cast-
ing to the base, but you are starting from the correct position with the column
square to the bottom of its mounting bracket.
MAINTAINING THE MILLING MACHINE
Oil and grease
Milling machines, like any other machine, require periodic lubrication. Try to
use the correct lubricant as specified by the machine tool maker, or if the ori-
ginal is not available use a recommended substitute. The internet is useful for
finding out the modern day equivalent of a discontinued lubricant or you could
ask on the Model Engineer forum ( http://www.model-engineer.co.uk ).
There will probably be oilers dotted around the milling machine's sliding
surfaces and you should top these up regularly. Check if the motor and any