Re: RTLinux lessons, and EDM's

Ian Wright wrote:

> Other than this monitoring, a wire EDM is just a 2D mill with a continuous
> vertical wire feed, spool to spool, in place of the cutter head. Whether the
> situation on a wire EDM machine changes dependent on the thickness of the
> workpiece I am not sure as I have never actually driven one.

No, not at all. The devices that hold each end of the wire are capable of
moving in 3 axes, so it is at least a 6-axis system. They can cut conical holes,
surfaces curved in 2 axes, all sorts of exotic stuff. Anything you can imagine
doing with a piece of string held taut between your two hands can be done
with wire EDM.

>
> The vertical plunging EDM is an altogether simpler animal. The simplest
> versions use a solenoid to push the ram down and contact with the work
> shorts out its drive voltage and makes a spark as it retracts and breaks
> contact - just like the 'interrupter' on an old sparking coil or magneto.

This will take days to do any meaningful work, unless the spark energy is
immense, and then you will have a very rough surface finish. Might as well
use a cutting torch.

My mini-EDM was doing about 60-100 discharges/sec when it was working
optimally. It sounded like a bad arc welder arc, in miniature.

Jon