Fly Cutter Attachment for Lathe Faceplate

[garage nut]

I just purchased a Lathe/Mill combination and the first thing I seem to need is a fly cutter.
Still recovering from the cost of all the tools and measuring goodies I find this an brilliant idea, only problem is I did not receive a face plate with my machine.

Now my question can I take a 3" disk and clamp it in the chuck and use it as the face plate or will the side forces damage my chuck?

Is the cutter hispeed steel? How is the cutting edge ground?