Project Beaver

[Neale]

Sorry - didn't mean to confuse but you said CSMIO first!

Yes, good choice of motion controller. Ignore the few posts talking about Mach3/CSMIO issues as you won't need to deal with these yet and we're not talking about show-stopper problems. NPN, N/C - yes, correct translation. The most important bit is N/C. If all the limit switches are wired with normally-closed switch contacts, then as soon as a switch opens, the machine stops. You might say that normally-open would do the same thing. The big safety-related difference is that if a wire comes loose, a soldered joint fails, you've forgotten to plug in the limit switches - with N/C connections then this looks like a limit switch has tripped and the machine stops/won't start. Bad connection with N/O switches and the first you know of it is when the gantry hits its end-stops and tries to keep going!

I agree that a box of the size that Clive suggests is about right. I used a 600x400x200 and although I could just fit everything in (by bolting lightweight power supplies to the inside of the door, for example) actually wiring the thing gets to be like keyhole surgery. A bit more space would help. I used an old PC case for my first machine, but that used a cheap, small, breakout board (the CSMIO needs rather more space) and I was using just 3 older analogue drivers which are a lot smaller than the newer digital drivers that I am using for Mk2. I was also able to use the PC power supply for 5V and 12V supplies but you are going to need 24V for the CSMIO.

Good luck - looks like you are going down the right path.