Page 3 of 4 FirstFirst 1234 LastLast
Results 21 to 30 of 36

Thread: Complete Shutdown

  1. #21
    Join Date
    Jan 2004
    Location
    Marietta GA
    Posts
    443

    Default

    Quote Originally Posted by Shayne Jenkins View Post
    Packet ET is between 15 and 19.

    I do not see any error logs in the event viewer.
    Hmmm... as far as I know, there’s no way for the control box to tell the SB3 software to shut down.
    Just losing Comm would result in an alert box that gives you the opportunity to retry communication or proceed in demo mode.

  2. #22
    Join Date
    Jan 2004
    Location
    windsor boat works limited, gravenhurst ontario
    Posts
    83

    Default

    I had a similar problem once wit my older machine . I could air cut the file no problem , but as soon as I started cutting the static would somehow back feed through the electrical ground and mess up my computer . I eventually ran an isolated ground to the Shopbot that wasn't common to the computers ground and the problem stopped

  3. #23
    Join Date
    Jul 2005
    Location
    Brookline, New Hampshire
    Posts
    434

    Default

    "I do have excess motor cable looped under the table" If it is all coiled in one direction, it forms an inductor (coil). It would only be a micro henry or so but still a coil. if you take half of the coil, flip it 180 degrees, and lay it on top of the other half, the halves cancel out each other. Per your description of your problem, I don't think a coil is your problem but it would still be good practice to eliminate it as a source of problems.

    Be sure that your data and power wiring are as far away from each other as practical avoiding mutual inductance.

    I would also recommend that you get a cheap AM pocket radio (with an earphone). Yeah, I know this sounds like a joke; It isn't. Tune the radio to part of the band where you don't hear any station. You now have an extremely sensitive RF sensor. If you experiment with it some, you'll find that the H Field (magnetic) antenna is highly directional.

    If you have an intermittent power connection you'll be able to here it and locate it by moving the radio around. If you use a single to three phase inverter, you are likely to hear that as well and will soon be able to determine normal operation.

    The radio will also detect static discharges as an audio "snap". You might want to record the audio. If the recording captures a "snap" and everything shuts down, you know what to look for.

    I have used this technique to debug an avionics computer. It served as another modality of detecting abnormal operation.

    The technique has also been used to detect the operation of electrical welders and plasma cutters at considerable distance even when there were no other indicators.

    Paul Z

  4. #24
    Join Date
    Nov 2011
    Location
    Akron, OH
    Posts
    24

    Default

    Quote Originally Posted by robtown View Post
    Hmmm... as far as I know, there’s no way for the control box to tell the SB3 software to shut down.
    Just losing Comm would result in an alert box that gives you the opportunity to retry communication or proceed in demo mode.
    I have tried hitting the E-Stop and sometimes the software shuts down there also. This leads me to believe the box or software is seeing the E-Stop is being pressed. The E-Stop is mounted on a small wood platform that I have tried shaking without triggering the stop so do not believe that it is a loose wire or faulty stop.

  5. #25
    Join Date
    Nov 2011
    Location
    Akron, OH
    Posts
    24

    Default

    I want to ask something that may seam obvious. Everything in the box is ground to the ground rod in the box and the box is mounted to the frame. All of this should run back to the AC power, right? So it should already be grounded back to the circuit breaker. I just want to be sure that if I am adding a ground it serves a purpose and does not make things worse.

  6. #26
    Join Date
    Nov 2011
    Location
    Akron, OH
    Posts
    24

    Default

    Quote Originally Posted by paul_z View Post
    "I do have excess motor cable looped under the table" If it is all coiled in one direction, it forms an inductor (coil). It would only be a micro henry or so but still a coil. if you take half of the coil, flip it 180 degrees, and lay it on top of the other half, the halves cancel out each other. Per your description of your problem, I don't think a coil is your problem but it would still be good practice to eliminate it as a source of problems.

    Be sure that your data and power wiring are as far away from each other as practical avoiding mutual inductance.

    I would also recommend that you get a cheap AM pocket radio (with an earphone). Yeah, I know this sounds like a joke; It isn't. Tune the radio to part of the band where you don't hear any station. You now have an extremely sensitive RF sensor. If you experiment with it some, you'll find that the H Field (magnetic) antenna is highly directional.

    If you have an intermittent power connection you'll be able to here it and locate it by moving the radio around. If you use a single to three phase inverter, you are likely to hear that as well and will soon be able to determine normal operation.

    The radio will also detect static discharges as an audio "snap". You might want to record the audio. If the recording captures a "snap" and everything shuts down, you know what to look for.

    I have used this technique to debug an avionics computer. It served as another modality of detecting abnormal operation.

    The technique has also been used to detect the operation of electrical welders and plasma cutters at considerable distance even when there were no other indicators.

    Paul Z
    This technique sounds like too much fun to not try even if I can solve this issue without it!

  7. #27
    Join Date
    Jan 2008
    Location
    Hobby-Tronics, Chiloquin Oregon
    Posts
    1,220

    Default

    This technique sounds like too much fun to not try even if I can solve this issue without it!
    Ahh, now we're havin' some fun! Your my kind of CNC'r!
    It's kinda like MY: If there ain't no blood, it can't possibly work!
    I seriously hope you find it though, I just hate intermittent issues, they just suck! Russ
    AKA: The Train Guy

  8. #28
    Join Date
    Dec 2011
    Location
    Piedmont, SD
    Posts
    646

    Default

    Everything in the box is ground to the ground rod in the box and the box is mounted to the frame. All of this should run back to the AC power, right? So it should already be grounded back to the circuit breaker. I just want to be sure that if I am adding a ground it serves a purpose and does not make things worse.
    My previous set up was exactly as you describe, PLUS I had a dedicated 6-8 gauge ground wire on leg of the shopbot's frame. I had lost communication issues regularly at this time of year.

    New Building, same setup, but the box is on the wall, no longer in contact with CNC frame. One year solid, no comms issues.

    I know you're not getting lost comm's message, but still appears static related.

    Key point here is the ground should look like branches on a tree as it terminates at every electronic device involved with running your cnc. If at any time two branches connect to each other, in this case the cnc frame and control box, trouble can arise, as that static charge (about 10,000V) may be inclined to travel through the control system vs. straight to ground. It's confusing, as you could run for months like this with no issue, but this is the time of year when atmosphere is dry, plus the fact you're cutting PVC means you're likely generating far more static than those of us who have fought this cutting strictly wood products.

    With your current setup as described, a static charge has the opportunity to jump back through the control box as it travels to ground. By isolating the frame, static discharge will have a path straight to your main building ground, vs through the delicate controls.

    All of this should run back to the AC power, right?
    Yes, it all goes to the same place, but best to give it a path that completely bypasses your control box and control computer connections. Electricity, like water, flows, and it will take the path of least resistance, so consider that chassis grounding cable as a first line of defense "trench" to dump unwanted charges to the ground vs. spilling over and "soaking" the sensitive controls.

    I would suggest removing the control box from the frame - set it on some 2x material on the floor temporarily. Connect a dedicated ground cable from the cnc table leg to your main ground. See if this separation of grounding paths alleviates the issue.

    Cheap, fast, easy test.



    Jeff

  9. #29
    Join Date
    Apr 2013
    Location
    Kennebunkport, Maine
    Posts
    4,006

    Default

    Just remembered a time when SB3 was totally kicked off.....it was a panic situation when I first started...and hit the Spacebar for a Pause like crazy.
    Sb3 just dropped off the screen and had to do an E-stop.
    Reoccurred when we had a "sticky" spacebar once also.

    Found the thread where Ted Hall explained that they were fooling around with multiple/fast Spacebar hits(5?) would shut down SB3.
    See hi lighted section of thread below.

    Probably not pertinent now as it was so long ago, but have you swapped out keyboard and mouse just in case, and one of them IS "Sticky", and that feature is still active in your version?
    Just mentioning.
    scott
    Scott Plaisted
    2013 Desktop/spindle/VCP 9
    Maine

  10. #30
    Join Date
    Nov 2011
    Location
    Akron, OH
    Posts
    24

    Default

    Thanks again guys. Jeff's suggestions are giving me some confidence in grounding properly. Will report back soon.

    Shayne

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •