wrote:

I have this mill(the 4H)
http://www.lathes.co.uk/armor/
at home, and have FINALLY gotten it under power. I am curious, how
does one go about tramming something like this so that the arbor is
truly perpindicular to the table travel. I imagine parallel is a
concern too, but I don't know of an easy way to correct that.

Does anyone have a procedure to tram something like this?
Just a newbie, with a question.


Attach a dial test indicator to the spindle, so it swings around in an arc.
It is best to actually mill a circular track, or mill off the whole surface
of some piece so that you have a face that is parallel to the plane of the
machine's motion. On a vertical mill, that would be done with an end mill
on the top of the work, creating a "replica" of the X-Y plane of motion.
On a horizontal mill, it would be the back side of whatever was on the
table,
I guess that would still be called the X-Y plane. This milled surface would
then be a replica of the plane defined by the knee and long table travel
axis.
The spindle should be precisely perpendicular to that surface.

This procedure can also demonstrate wear in the ways that causes the table
to rock or travel in an arc-like motion, because the surface may come out
with dips and hills. You might want to mill the top of a block with a
narrow
horizontal milling cutter and check the surface for flatness. There is
usually
a hollow worn into the middle of the underside of the table, so things
machined
on the top will have a high spot in the middle.

If you mean just checking that the outer arbor support is true with the
spindle,
I'm no expert, but I think you run a dial indicator along the arbor and
make sure
it is parallel to the table Z axis, both in the up-down direction and
the left-right
direction.

Jon