[FreeZey]

I've recently got my solsylva build CNC Router going and I'm using the Hobby CNC Pro Rev 1 controller board with the 305oz unipolar steppers. I was wanting to get a breakout board for added protection for my PC and was wanting some opinions about what might be best to use in combination with the HCNCPro controller board.

I've read over things here in the forums and google'd various products but I was wondering if there was anybody running a similar setup with the HCNCPro, what they ended up choosing, and how it performed.

Any help greatly appreciated! :banana: (<---Couldn't resist)

[ger21]

I was wanting to get a breakout board for added protection for my PC and was wanting some opinions about what might be best to use in combination with the HCNCPro controller board.

None.

In the 8 years I've been here, I may have seen one damaged PC, and if it was, it was probably due to a serious wiring error. Damage to the PC, although probably possible, just doesn't occur. Imo, a breakout board for a HobbyCNC wold just be wasting money.

[microcarve]

I agree with Gerry. Not really needed.

I've used 5 Hobbycnc boards...Very Good boards, BTW...and never
used a breakout with any of them.

You can always add in a separate parallel port card just for the
heck of it if it makes you feel better. It can't hurt anything and they're
pretty cheap.


John

[tkubic]

On the hobbycnc controllers the signals are filtered by a schmitt trigger (it's a chip on the board). I'd imagine if there were any short circuit it would blow the schimitt first.

I suppose it is technically possible to short to the parallel port, but unlikely.

I just use a really old laptop. If it dies I have several other old desktops waiting to take it's place, lol. My greatest concern would be blowing my driver board / transformer / filter capacitor / stepper motors

[FreeZey]

Gerry,

Well I guess I can tell you about number 2 then. I'll explain as best I can and maybe you guys can help me out alittle. I just know I don't want to kill another computer! (chair)

Basically what happened was I accidentally ran over a limit switch and broke it. No biggie it was only a dollar right? So my father was going to swap it out while I worked on something else. He apparently tried swapping it hot while the power was on because he's changed micro switches at work this way numerous times with no problems.

Unfortunately, when he cut the wire to the limit switch all my motors jerked and the computer abruptly shut off. Long story short, the computer was dead and wouldn't even post, I suspect a blown power supply seeing as how I couldn't visibly see any damage to the motherboard. Regardless, it was old to begin with and expendable, so I threw it to the side and built another one with spare parts I had this time with an expansion slot parallel port card.

Everything works great now but I'm concerned with my wiring. My father has 40 years experience as a machinist and I've built numerous computers but neither one of us know a whole lot about electrical wiring particularly when it comes to grounds and earths. I mean we can follow a good schematic (I built the controller after all miraculously!) but that's about it.

The limit switches are wired up NC in series like I read to do in numerous places. So when you trip a switch it "breaks" connection, this way if a wire breaks it will throw a limit and you'll know about the problem. Makes sense to me, but how is tripping the limit switch any different from cutting the wire? And why would that have ran in on the computer and blew it? That's my concern for wanting a breakout board. Unlike the other computer, this one is actually worth a few bucks and worth protecting.

Like I said, it's a HCNC Pro Rev 1 board, running the 305oz steppers. I've wired everything up the best I could according to the diagrams that came with the kit and I used the lower cost option transformer but verified that was hooked up correctly through the yahoo group. Let me know what other info you need and I'll answer it to the best of my abilities.

And Thanks for the other responses guys!

[ger21]

So when you trip a switch it "breaks" connection, this way if a wire breaks it will throw a limit and you'll know about the problem. Makes sense to me, but how is tripping the limit switch any different from cutting the wire? And why would that have ran in on the computer and blew it?

Cutting a limit switch wire shouldn't cause any damage. I can't tell you what happened, though.
But, everything should be OFF when doing any wiring. EVERYTHING.

[FreeZey]

Cutting a limit switch wire shouldn't cause any damage. I can't tell you what happened, though.
But, everything should be OFF when doing any wiring. EVERYTHING.

Well that's the problem. We didn't think it should have and every electrician we've talked to said it shouldn't have but it did, hah! (nuts) I'm at a loss of what to do really, because I'd like to understand what went wrong.

[2slaps]

The only thing I could think off that would sent your computer into smoke is maybe when your dad cut the limit switch...he might have had a contact with the controller board or other things along that line. Perhaps your dad had static when he made the cut? :P I've heard stories of people blowing things up because they don't turn off the power source or their ground is faulty.

[Al_The_Man]

If you limits switches are source devices, IOW they switch the +ve voltage, whatever you are using, 5v,12v 24v etc, and the grounded shield was cut through at the same time, this will likely blow the supply, or if no shield was used, in cutting the cable he made contact with ground.
If the switches are sourced from the PC, the PC P.S. common is at earth ground potential.
Al.