Home switches,E-stop advise

[jcwebb]

I plan on buying a 4-axis Xylotex board for my cnc.
I want to connect home switches and an e-stop.
From what I've read ,I will need a break-out board for that.
So I plan on gettting the Cnc4pc break-out board.
Is this all I need? Or do I also need the mini power supply?
What does the parallel port interface card do?
Please help because I've spend a million hours looking at the forums and the more I try to learn ,the more confused I get.

Thanks,
John

[ger21]

The Xylotex has terminals for the unused parallel port pins on it. You should be able to hook your home switches up to those, and not need the additional break out board.

As for E-stop, there are many different ways to do it. With Mach3, you can use another pin on the Xylotex to trigger a software E-stop.

So the Xylotex should be able to do everything you need, with nothing else needed. You might want to email Jeff at Xylotex. He's very good at answering questions, and pretty quick, too.

[jcwebb]

Thanks for the fast reply!!! I will e-mail Jeff to see what he thinks.
As far as the E-stop goes, I'm more comfortable with a big red button to hit rather than a software E-stop. I will ask Jeff if this is possible with his board.
Thanks again,
John

[ger21]

You would still use a big red button, but if wired into the Xylotex (or a breakout board), it would be just telling the software to stop. You could also wire it to the enable lines on the Xylotex as well.

A true E-stop should cut power to the drives and spindle. This is usually accomplished with relays. Check with Jeff, but I think it's best to cut the AC to the power supply, NOT the DC to the Xylotex.

Like I said, there are several different ways to do an E-Stop.

[jcwebb]

Why do some people use a break-out board if they can just use the driver board terminals?

Do most people use a software e-stop or do they interupt the power to the spindle/motors?

[ger21]

Why do some people use a break-out board if they can just use the driver board terminals?

Not all drives have provisions for switches and relays, so that's why they use a break out board. Geckos, for example just have inputs for step and direction. No parallel port plug.

[jcwebb]

I mean for people that run xylotex boards.
If it is possible to hook-up home switches and an e-stop on the xylotex board,
then what is the advantage in using a break-out board?

[ger21]

If there using a second parallel port, then you can hook up more switches, or relays, or MPG's, or whatever else you might want to use.

[impact]

I am wanting to do the exact same thing but I have a couple more questions...

I am also running a xylotech board. I am guessing the ports arn't isolated is there really that much danger to you computer?

What is the advantage of optical homes? More accurate? As limits it doesn't really matter if they are optical or just snap switch?

I also want to run a coolant on off? How can I go about doing that? I guess I need some sort of relay?

[jkeyser14]

The new 4-axis xylotex board (as of last winter) that I have doesn't have terminals for unused pins.

[Bowman]

Impact - The break out boards I have been looking at buying use opto-Isolation to prevent any current from going back to the PC through the port. I think this is one of the main advantages to using a seperate breakout board in addition to what Ger21 said about allowing you to use another parallel port to add on many more features and it keeps all those functions seperate from your controller port. Same goes for the relays I have been browsing they all are opto-isolated to prevent current going back to the breakout board/pc. At least thats my take on how things work from the searching I have been doing into breakout boards and relays for my xylotex.


Good Luck
Bowman

[ger21]

Impact - The break out boards I have been looking at buying use opto-Isolation to prevent any current from going back to the PC through the port. I think this is one of the main advantages to using a seperate breakout board .....

Jeff at Xylotex has posted recently that he is not aware of anyone's PC ever being damaged this way while using a Xylotex. And come to think of it, I'm not sure if I've heard of anyone's PC being damaged with any drives, at least not in the last 2 years or so that I've been here. I also read a few Yahoo groups daily. While a lot of people make a big deal about isolating the PC, damage caused by no isolation just doesn't really seem to happen. At least I havent seen it. Not that it couldn't happen, though.