> So you keep the driver board.

Yes. I'm assuming it is already matched to the drives, so didn't see the point in taking it out and replacing it with new drivers.

> What does that mean for the performance? is it more on the slow side? And what about the precision?

I have no idea, but I'm only using it for hoppy purposes, so speed is ot an issue, and the manual states an accuracy (step resolution) of 0.01mm, which is good enough for me.

> Do you know how many steps are to a millimeter? half step? quarter step?

Not yet. I have all that to work out once the electronics are finished.

> I used the planet cnc in the past and wasn´t very happy so I would like to stick with Eding if possible

I would be interested to know why you weren't happy - off line if you like ? I've not used mine in anger yet, it arrived with a CNC router I purchased a while ago, but a quick wire up with each axis seemed to operate OK.

> How do you tell the ATC to react, when changing tools?

The original control system just used one button, to rotate the turret by one tool location and then reverse it into a latch to lock it.
The Mk2/4 controller I have can't do that, so I'm planning on using the jog keypad to manually rotate the turret for tool changes during program pauses.

> How many hours would you think I have to invest to rewire it all?

It depends :)

Having spent ten or so hours investigating it, I would estimate that it would only take two to three hours to rewire a second one, assuming all the parts needed were to hand.

I've no proof yet that my planned changes will work first time though ;-)

Adrian.