The T nuts are made from round material, so, using the lathe, first drill, tap and
part off to length. Holding such a small item for milling the rebates can be a problem
and holding this across its curved surface between the vice's jaws unaided is definitely
a no no. Placing a small V block on its side and holding the disk between this and
the moving jaw of the vice as seen in Photograph 14 will achieve a much more secure
hold as the disk is being held at three points rather than two. With that done the
disk can be machined to provide the T nut form.
The nut is also machined to reduce its width a task that may appear unnecessary but
as the faceplate has a rim on its rear the extra width will prevent the nut from
using the full length of the slots, of course it is only by a very small amount so
you may choose to bypass this operation. If not, then we have a small part that is
difficult to position when using the vice and my method is worth considering.
Mount a fence on an angle plate and, using a square, ensure the face is upright then
fit a second so that the already machined rebates sit snugly between the two. The
T nut can then be securely mounted using a screw from the rear of the angle plate
and using the nuts own thread, place a spacer of some form below the nut will set
the height and the first side can be easily machined, Photograph 15. With that done
loosen the nut, turn over, and place a 3/16" piece of packing on top of the spacer
and machine the second side, easy!
These are the two items seen to the right of the three T nuts in Photograph 10 the
purpose of which is to provide a surface from which the distance of the angle plate
to the faceplate's centre can be easily set, Photograph 16. In this, the distance
from the Setting Pin mounted in the Setting Hub is being positioned using a bore
gauge set to the required value. The Hub is entered into the faceplate from the rear
and is a close fit in both the parallel bore and the root diameter of the thread.
It is a simple item to make needing only the diameters to be a close fit and these
concentric with the hole that takes the pin. Having positioned the angle plate the
casting is added for boring as shown in Photograph 17. This Photograph is using an
already completed workpiece and is just to simulate a typical operation for the purposes
of this article.