Page 1 of 2 12 LastLast
Results 1 to 15 of 24

Thread: DVR XP shuts down

  1. #1
    Join Date
    Aug 2007
    Location
    Hampton Roads, Virginia
    Posts
    894

    DVR XP shuts down

    Any DVR XP owners experienced anything like this?

    My Nova DVR XP shuts down while using a buffing wheel. I've not used a buffing wheel on this lathe before and generally I will use other motors but I tried it out and the lathe shuts down under load.


    I removed the wheel and mounted a bowl blank and turned with no issues.


    I unplug the lathe after use so the software settings would have been at the factory defaults. I'm wondering if the software thinks a load like this means something is wrong and if the setting need changing but I can't find a clear explanation of what the setting mean. What are PI Speed Control coefficients? What do the Kprop and Kint values mean?

    I hope it's not a bad board - they're not cheap!
    RD

  2. #2
    I'm surprised that running a buffing wheel is causing any issues... I'd definitely get in touch with Teknatool on this. When the machine shuts down does it show any error codes?

    But to address your other question, those properties are all PID Controller constants. Sounds like the DVR uses a PI controller (described in that link), and those two values control the motor's speed in relation to what you have it set to on the RPM dial. I don't feel that messing with them will fix your problem especially seeing as how you're using factory default values.

  3. #3
    Join Date
    Mar 2015
    Location
    cleveland,tn.
    Posts
    385
    could you be leaning on the buffer to hard and overheating the motor? there should be a temp. usually in C where it should run stamped on most electric motors . You could check it with a digital thermometer . I do not know for sure on your lathe , just most electric motors.

  4. #4
    Join Date
    Mar 2007
    Location
    Wetter Washington
    Posts
    888
    #1: Unplugging the lathe will not force it to factory default settings, those are in EEPROM and retained. You can change the factory settings, but then these changes are retained, even when the lathe is unplugged.
    #2: The lathe features a "stop on catch", as I recall this can be set to one of three settings "soft", "med" and "hard", the factory default is "med". I've never gotten a DVR to stall on buffing, but maybe you are leaning into it harder then I am. You can change these settings and the instructions should be in your manual. If you are getting no stalls on turning, I suspect you maybe pushing too hard on the buffing.
    #3: Kprop, Kint, etc are control system parameters and you should not try to change those unless you know exactly what you are doing (I own a DVR-XP, have and EE, I also worked in control systems and I wouldn't try changing them.
    #4: I've never managed to get the motor to shut down for heat, I'm not certain what it would take but the shop was once ~100F and it worked fine.
    Making sawdust mostly, sometimes I get something else, but that is more by accident then design.

  5. #5
    Join Date
    Aug 2007
    Location
    Hampton Roads, Virginia
    Posts
    894
    Thanks everyone,

    I have contacted Teknatool and sent them a short video. Just sent them a list of parameters they requested. This was accessed by entering service mode. You may have to register for the link to work but there's a lot of info in the library.

    No way the motor overheated as the shutdown happens within 3-5 seconds of engaging the wheel. I really don't think I was being too aggressive. I tried several times with different approaches - but I'll try again.

    Ralph,
    1. I may not understand exactly what they meant but this is from the manual"
    Hard Reset Function
    Press key <OFF>
    hold it and then press key <DOWN RPM>
    in order to provide the Hard Reset of the drive.
    Another way is to switch off the power, wait 10 seconds and switch it on again. Use this function if you
    want to return the factory-preloaded values of the drive parameters. Also, try to use this function if you
    have a problem with the drive, for example, if the system is not responding to the keys.

    2. This was my thought also but I didnt find the meaning of SOFT vs NORMAL vs HARD in my manual. Still have not tried this as I'm waiting for Teknatool feedback.
    SOFT: For light work at speeds lower than 500 rpm
    NORMAL: Suitable for most work and is the default setting
    HARD: For heavy and/or ‘out-of-balance’ work at speeds lower than 500 rpm

    3. I hear you!! In fact I've learned that control panel keys have functions that may be invoked by pushing specific combinations. Maybe I screwed up something in the past that I wasn't aware of because the lathe operates for normal turning.
    4. I've never had heat related issues either. I'm in the Southeast and my shop gets pretty hot.
    RD

  6. #6
    Join Date
    Oct 2009
    Location
    McMinnville, Tennessee
    Posts
    1,040
    I use my DVR-XP with buffing wheels all the time with no problems.
    Sid Matheny
    McMinnville, TN

  7. #7
    Join Date
    Feb 2010
    Location
    Hanover, Ontario
    Posts
    405
    Richard. I am going to follow this thread, I have not had this problem with my DVR XP in the 6.5 years of ownership and very frequent use...
    It will be interesting to see what the Technatool staff come up with.
    I think if you just press the Program button you should see the setting for Soft, Med or Hard. Just take a look, you should be on Med setting.

  8. #8
    Join Date
    Aug 2007
    Location
    Hampton Roads, Virginia
    Posts
    894
    Teknatool has been very responsive so far. They sent me some suggestions to try. I'll report back.
    RD

  9. #9
    Join Date
    Oct 2006
    Location
    Harvey, Michigan
    Posts
    20,801
    Richard, I do not have a DVR XP but am curious about what speed you are running the buffing wheels at? Have you tried a different speed to see if that makes any difference? Seems odd that you can turn a bowl (load on the motor) and can not run the buffing wheels (no load).
    Steve

    “You never know what you got til it's gone!”
    Please don’t let that happen!
    Become a financial Contributor today!

  10. #10
    Quote Originally Posted by Richard Dooling View Post
    ..... This was my thought also but I didnt find the meaning of SOFT vs NORMAL vs HARD in my manual. Still have not tried this as I'm waiting for Teknatool feedback.

    • SOFT: For light work at speeds lower than 500 rpm
    • NORMAL: Suitable for most work and is the default setting
    • HARD: For heavy and/or ‘out-of-balance’ work at speeds lower than 500 rpm ...
    The terms Soft Reset and Hard Reset have nothing to do with how or what you are turning. Sort reset refers to resetting via software control while hard reset is a hardware controlled reset. Resetting via software may not reset everything.

    I have a question. Are you running the buffing wheel in reverse? There is a possibility that a fault condition is detected because the load you are applying is greater than expected for reverse turning ... sanding is typically the only operation done in reverse.

    Another thought would be that the inertial load of the buffing wheel is extremely low, but the torque load of heavy buffing creates an unexpected high load condition that doesn't appear to be normal given the low moment of inertia.
    Bill

  11. #11
    Join Date
    Aug 2007
    Location
    Hampton Roads, Virginia
    Posts
    894
    Lots happening on this and I'll try to give a more through recap later. I'll have some info that some DVR XP owners may find useful.

    Bill my item #2 that you quote was in response to Ralph's item #2, "The lathe features a "stop on catch", as I recall this can be set to one of three settings "soft", "med" and "hard . . ." This is a function of lathe operation and how the motor reacts to turning conditions. I was not referring to a soft or hard software reset but an available parameter setting that changes motor operations.

    From the manual: "
    You may wish to change the stabilization setting from time to time depending on the type of work piece you are working on. You have 3 options preset for you: " (SOFT, NORMAL,HARD)

    Maybe I'm not understanding you?
    RD

  12. #12
    Join Date
    Aug 2007
    Location
    Hampton Roads, Virginia
    Posts
    894
    This post is a recap of what happened with my DVR XP shutdown.


    • I was regularly experiencing a shut down when trying to use a Beale buffer. This is the first time I’ve used a buffer on this lathe.
    • The lathe was in forward rotation at 750 rpm and only shut down under a load.
    • It shut down the first time I engaged the wheel.
    • The display looked normal and the lathe started back up with no problem until I engaged the wheel again.
    • It shut down no matter how light or aggressive the pressure but turning a bowl blank did not cause a shut down.
    • I shut down power to the lathe, unplugged it, waited a few minutes and booted back up. Still the same behavior.
    • Set my hair on fire, ran around the shop, used bad language.
    • Came inside and contacted Teknatool and Sawmill Creek.


    The next day things generally ran fine with occasional stalls.

    I had several exchanges with Teknatool. They have been really trying to figure this out for me. They sent me instructions to access service mode and asked me to record all the listed operating parameters. The instructions included a chart with the normal baseline numbers. I had two settings that varied from the baseline and they sent me instructions on how to change them.

    They also mentioned that there might be “noise/interference from somewhere.” I assume they mean electromagnetic interference. They advised me to try putting a ferrite choke on the main control panel ribbon cable. I asked if a big honkin’ magnet on the headstock might be suspect. Have not heard back and I haven’t installed the ferrite choke.

    Wednesday I made the recommended changes to the two operating parameters. No stalls. Thursday and Friday I tried various combinations of magnet on the lathe and off, aggressive engagement of the wheel and various speeds. I tried everything I could think of to stall the motor short of causing damage to the machine or me. It has not stalled once.

    So apparently problem solved. I guess changing the parameters fixed it. But day two I only had one stall and that was before I changed the parameters, so I’m still not sure just what was happening.

    Thanks very much for everyone's advice and interest. I was pretty worried what with the price for a new control panel board!

    DVR XP owners:

    Here’s something that was not obvious when I went in to change settings.

    The screen displays two parameter values at a time.
    Press and hold <FWD-REV> button and then use UP and DOWN to move between the two displayed parameters. This changes which one will be edited.

    This PDF includes a chart of the baseline values and my recorded values.
    NOVA DVR XP Ser.pdf
    Last edited by Richard Dooling; 04-16-2017 at 10:20 PM.
    RD

  13. #13
    Join Date
    Mar 2007
    Location
    Wetter Washington
    Posts
    888
    Thanks for the update
    I usually buff at 1800 rpm
    Fixed field magnets should not effect the lathe (my headstock is covered with magnets and has been for, years)
    EMF, ya that could, but that's a changing field.

    I just had to take my tails-stock apart, the handwheel was sticking really badly. I ended up honing (brake hone on a drill) on the shaft opening of the tail-stock, then wiping it out. I'm going to guess it was wood dust ground into the fit-mit too hard for just wiping out with a cloth.
    Making sawdust mostly, sometimes I get something else, but that is more by accident then design.

  14. #14
    Join Date
    Aug 2007
    Location
    Hampton Roads, Virginia
    Posts
    894
    Thanks Ralph,

    That makes sense. The magnet is not in motion so no current no EMF. Yes?

    The ironic thing is that I never meant to regularly use the buffing wheel on the lathe. I've got a rarely used Shop Smith that will do nicely for this.

    I've been playing around with speeds and 750 is just what I chose to go out for a test drive. Then I found myself in the middle of trying to figure out why my lathe was shutting down.

    Today I was at about 1400 rpm with a pretty light touch and got some nice results. So much of the key is in the prep. The buffing actually goes pretty fast.
    RD

  15. #15
    I had the same problem. Attaching a grounded wire directly to the lathe bed eliminated the problem for me. Hope this helps.

Posting Permissions

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