Here is a link to a small clip of the machine routing a moi boolean into pink foam:

http://www.onesmall.com/stuff/MVI_4792.AVI

I took the foam, dipped it into a slush of fire proof cement and then packed it into sand.
Then I used my little foundry to melt aluminum and filled poured that into the foam form.
The foam vanished instantly when the molten metal touched it and the product was an exact replica of my foam piece.
The test worked very well and my next experiment will be something more substantial.

It's almost winter now and casting outside is fun.
You face is nearly boiling off while the rear is frozen stiff...

Next improvement is a cable management system. With the high speed movements the cables really start to swing.
It's impressive how quick the machine can go considering that the gantry is about 200lbs.. My design efforts paid off.
The router in the first images is still in the shop but I did not use it any longer as I got hold of an industrial spindle.
The difference is that the spindle is driven by 0-400 Hz frequency and the router motor works like a vacuum cleaner motor.
Running the spindle 8 hours is no problem. The hobby router will die sooner or later.

Cheers
Lemo