Re: [CAD_CAM_EDM_DRO] mirror finish on aluminum?

stratton@... wrote:

> > > I have a retrofited RF 30 and I'm trying to get a mirror finish on a
> > > 4"x4" piece of 6061T Aluminum. I'm using a 3" fly cutter with various
> > > tooling but I just cant to get a mirror finish. Is it posible? Or is
> > > there another step after milling to get a mirror finish. I know the
> > > head needs to be trammed but figured that would'nt effect this.
>
> I've never tried to do this myself, but I would think that if the head
> is even slightly out of tram - ie, is not perpendicular to the table,
> then the fly cutter will cut semicircular gouges into the work. A lot
> of fly-cut stuff looks that way...

Well, I'm talking VERY slightly out of square. Somewhere around .001"
higher on one side of the pass. That's .001" over whatever diameter the
fly cutter edge is sweeping. This is just to keep the edge from making a
surface burnishing pass over the already cleanly cut surface.

> Even if you feed slowly enough that the fly cutter makes a smooth
> pass, it would be concave rather than flat, and there would be a ridge
> if you needed multiple passes to cover the work.

The concave feature would be VERY small, about a half of the .001"
difference between the two measurements on the 'high' and 'low' side.

The idea is to set the fly cutter wide enought to cover the entire width
of the work in one sweep.

Jon