Hi Bob,my mate fixed an electric spark eroder a year back and said it was cool at cutting 3D interior shapes.Heard of such device?
Nature has created so many life forms but none with wheels?
I have come across spark eroders in the past. There was one described in one of the model engineering magazines a few months back. One of the best things they can do is burn broken taps out of holes. I can see in model making lots of uses, basically if you can make the female plug you can then sink that into almost any metallic object that will fit in the machine, hardness seems to be no object. I think older systems used paraffin as a working fluid, but believe this has been replaced with a non-inflamable liquid in modern machines.
Only very limited progress on the CNC miller idea. The book I refered to was not much use, mostly aimed at making a CNC router. As I already have access to a Denford Compact 1000 CNC router there was little appeal to making another one. More excited by the idea of making a Reprap machine. Have got as far as buying the stepper motors and most material to make the frame, but as ever time is against me, just not enough hours in the day and my home shop is too cold to work in at this time of year (-4.4 C this morning). I have made loads of other stuff since this posting, a neat little synth from Music from Outer Space ( http://www.musicfromouterspace.com/ ) and several hot air (Stirling) engines. Still busy with stage tech work, just starting a four night run of Carousel tonight and at the momment a whole dimmer rack is SNAFU so it looks as if I need to repatch the whole board before 7.00 pm tonight. On top of all this the Day Job is getting busy.