Head slapping moment

Well if you have seen my threads in the past you may know that I have had a "gremlin" that throws an estop every so often. Completely random and usually very rare. Well I had to do some machining this weekend and was pretty nervous because it was my first time machining stainless. Well about 10 minutes into my spindle warm up it throws an estop. Great. Ok reset and continue. Everything is fine. Start cutting and my speeds and feeds were working perfectly and... estop. Damn! Reset and start again and ... estop. Well at this point I am pissed because the part I was cutting had to go out on monday. Kept trying it, kept getting estops. Forget it! Clean off the machine and be done. Well as I was cleaning it, I decided to give it one more go. And to remove my pendant. What do you know.. no estops. Not sure if it was the pendant itself or the USB extension or whatever.

I guess the old computer advice really does work. Unplug everything and try again...

-keith

It was a rare occurrence on my Torus, but it did happen. Head scratcher for sure.

It hasn't happened at all on the Pulsar. Biggest difference is the smooth stepper. I don't use any pendants though. Keyboard and mouse is all.

Glad to hear that you found the culprit.

Keith,

What kind of pendant? How is E-Stop connected? E-Stop really should be hard-wired, not dependant on USB or anything else. I'm a big fan of the VistaCNC pendants. I've had several, and love them.

Lee,

You really should try a real pendant with a good MPG. You have no idea what you're missing. I rarely need to touch the keyboard, except for loading a new program and setting up the tooltable. Everything else I can do quicker, easier, and with greater accuracy using the pendant. It gives me full control over Run/Stop/FeedHold/Step, spindle and coolant, jog speed, step increment, setting offsets, etc., etc. It's ideal for "manual" milling as well. Using the keyboard is like working with one hand tied behind your back.

Regards,
Ray L.

It is a vista cnc one. I have an estop hardwired on the mill but there is also an estop button on the pendant itself.

Quote:

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Originally Posted by keithmcelhinney

It is a vista cnc one. I have an estop hardwired on the mill but there is also an estop button on the pendant itself.

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Keith,

Talk to Lee at VistaCNC. He'll get you fixed up. I do know USB hubs, though simple enough in concept, are often very poorly implemented. I've had one for years that I've suspected for some time of being flaky. My keyboard mouse, and USB control panel for the mill would randomly go out to lunch on me. I finally got rid of it last week, and all the problems I've had with USB peripherals are completely gone. Try swapping out, or eliminating, any external hubs, and see if that helps. Be especially wary of non-powered hubs when using longer cables.

Regards,
Ray L.

Yeah when I have time this week I am going to plug it directly into the back without the USB hub in there. I have a feeling that is what is causing it. When you think about it, I have a USB cord from the motherboard to the side of the machine, then a USB hub with a long cord and then the pendant with a long cord. Can't be that good....


-Keith

I suspect your problem is electrical noise. Stepper motor drivers create very fast voltage transients which result in EMC problems. You could try a very simple resistor capacitor filter for your EStop to filter electrical noise. Better would be to check you cable screening an ground connections. Make sure electrical enclosures are grounded, cables are screened and the screens are connected at one an good ground end. The fact that the machining stainless increses the frequency of e-stops could be related as the cutting forces are higher. Resulting in higher stepper drive currents and higher mag fields.