This Milling Drilling Spindle was originally designed for use directly on the lathe,
comparable to many other similar spindles used in this way. Some viewers may like
to make it purely for use in this way rather then part of a Milling Head . For a
typical application of it being used a black and white scan is provided here. Often
spindles used in this way are driven from an overhead lineshaft giving considerable
freedom to how and where the spindle is fitted.
AS3 Manufacture of the spindle assembly, Photograph 20, is already covered in detail
in my book "Lathework a Complete Course" which should be viewed if you require help
beyond the limited guidance below, and that given with the drawings included on
the site. It is totally a task for the lathe and with most of the items being very
straight forward, it is only concentricity that needs particular attention.
Spindle S1 The bulk of the work on this should be carried out with it mounted between
centres a method that ensures concentricity, even with the need for the part be removed
and replaced, also turned end on end. First, mount in a four jaw chuck and set to
run true, support the outer end with a fixed steady and centre drill and drill 5.2
mm. Turn over and repeat but this time drill 6 mm. The drilled centres must be larger
than the 5.2 mm and 6 mm diameters so that there is still some centre impression
left for supporting on the lathe's centres.
Mount between centres and turn all the outside diameters and threads, including skimming
the 20 mm bar diameter to ensure that it is concentric with the remaining diameters.
Hold the spindle in the four jaw chuck on the 12 x 20 TPI thread, suitably protected
of course, and ensure that adjacent to the thread it is running true. Whilst supported
by the tailstock centre, fit the fixed steady to support the 20 mm diameter.
Remove the centre and fit the collet chuck body (S8) that has already been part machined
to make this possible. Bore the 10.5 mm diameter and both internal and external tapers.
It may also be opportune to similarly finish the adapter, L1, at this stage, see
comments re this in later pages. Remove the collet chuck body and now that the centre
is no longer required in the end of the spindle the 8 mm bore can also be made.