6 Mar
2014
6 Mar
'14
12:32 p.m.
On Mar 6, 2014, at 2:36 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
...And yes,I've centred many thigns in the 4-jaw
with a DTI. But there is
oen crucial difference. With the 4-Jaw, you can lightly clamp the object
with 2 of the jaws, then cetre in in the other direciton using the other
2 jaws to move it -- effectively using the screws of the chuck as
pseudo-leadscrews. But with the RK05 platter, there is nothing to move
it, just a clamping ring. It would be more like (for the lathe analogy)
trying to cntre something on a faceplate and then clmping it down. A lot
harder.
I am thinking I might make a fixture with some screws/pads to ba able to
move the platter slightly wrt the hub.
You?re quite right. The question amounts to the required accuracy for such a fixture.
From what you?re saying, it should be doable for an amateur to make.
Another possible approach, if the platter diameter is consistent within the runout
tolerance, would be to make a fixture that?s simply one large block of metal. Essentially
the cone tip of the hub, and concentric with it an opening exactly the right size for the
platter. It would take a fairly large lathe to make that, but the nice thing about it is
that it could just be cut in one sitting on any ordinary lathe, so long as the spindle is
in decent shape.
paul