Page 3 of 4 FirstFirst 1234 LastLast
  1. #21
    Well only two years later and my mill has become my primary project and I have made some progress.

    I have the RMHV controller hooked up to the EM806 drives connected to the original steppers. I have also connected the home switches. I have used the original power supply and relay board for this.

    Click image for larger version. 

Name:	20181227_165054a.jpg 
Views:	61 
Size:	223.4 KB 
ID:	25335

    This gives me the following good things.

    1) Movement on all three axis
    2) Control of all three axis using either the buttons on the controller or a MPG pendant
    3) Homing set up.

    What isn't so good is
    1) the z axis brake is errrr .... broken (I managed to loose the spring that applies the brake)
    2) More of an issue is I let the smoke out of the spindle dc driver. The good news is they are still available off the shelf the bad news is they cost about 200 quid....
    Click image for larger version. 

Name:	20181227_153303a.jpg 
Views:	49 
Size:	366.1 KB 
ID:	25334
    I have a replacement (https://www.transdrive.co.uk/shop/pr...q-non-isolated) and I'm in the process of wiring it up.

    To start with I have copied the settings (potentiometers and dip switches) from the old board but I'm now beginning to doubt the wisdom of this as the old board died on me and at some point previous to me finding it on a scrap heap someone has written the word BAD on the heatsink.

    I'll need to find some info on the motor as the old board is set for max voltage of 50V which seems a bit low (ISTR Triacs go up to 180V). I'm also trying to figure out how to use the 0-10v output from the RMHV controller to set the speed as I'm not sure if I need some form of isolation between the two.

    Hopefully I'm not too far from being able to cut some chips although I'm starting to think that I might be better off using MACH3/4 or Linux CNC rather than the rather limited RMHV controller.

  2. #22
    I'll need to find some info on the motor as the old board is set for max voltage of 50V which seems a bit low (ISTR Triacs go up to 180V). I'm also trying to figure out how to use the 0-10v output from the RMHV controller to set the speed as I'm not sure if I need some form of isolation between the two.
    I have just converted a Novamill that seems to have had the same control board. I used one of these https://www.ebay.co.uk/itm/111654184682 and a small 230V ac to 15V V DC power supply https://www.ebay.co.uk/i/26304063959...r=562044038463 so to keep the isolation from the motor control board.
    ..Clive
    The more you know, The better you know, How little you know

  3. #23
    m_c's Avatar
    Lives in East Lothian, United Kingdom. Last Activity: 4 Hours Ago Forum Superstar, has done so much to help others, they deserve a medal. Has been a member for 9-10 years. Has a total post count of 2,256. Received thanks 280 times, giving thanks to others 6 times.
    Quote Originally Posted by Clive S View Post
    I have just converted a Novamill that seems to have had the same control board. I used one of these https://www.ebay.co.uk/itm/111654184682 and a small 230V ac to 15V V DC power supply https://www.ebay.co.uk/i/26304063959...r=562044038463 so to keep the isolation from the motor control board.
    I think the RMHV is essentially the same as the DDCSV, and I don't think there is an option to use step/dir for spindle control. And I don't think the 0-10V is isolated. The only way you could get it to work with a non-isolated drive would be with a 0-10V to 0-10V isolator, but they aren't common or cheap (IIRC the last time I looked they were upwards of £150).
    The easier option would of been to get an isolated Sprint drive, however experience has taught me the motors on these are far more likely to fail and cause the speed controller to fail, rather than the controller to fail.
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

  4. #24
    Your right the RMHV and DDCSV are more or less the same.

    I'll use a pot connected to the sprint board for speed control for now.

    After a bit of digging on the internet and head scratching I *think* I've figured out why the speed control was set for 50v. I think that the 50v is the voltage from the tacho at max speed rather than the max output.

    But worried about your comment regarding the motor failing taking out the speed controller, what tests can I do on the motor to establish if its good or not?

  5. #25
    I think the RMHV is essentially the same as the DDCSV, and I don't think there is an option to use step/dir for spindle control. And I don't think the 0-10V is isolated. The only way you could get it to work with a non-isolated drive would be with a 0-10V to 0-10V isolator
    Not sure what you mean here, would you mind elaborating please.. I used the pwm signal from my bob and the https://www.ebay.co.uk/itm/111654184682 to convert it to 0-10V isolated for the spindle driver board.
    ..Clive
    The more you know, The better you know, How little you know

  6. #26
    m_c's Avatar
    Lives in East Lothian, United Kingdom. Last Activity: 4 Hours Ago Forum Superstar, has done so much to help others, they deserve a medal. Has been a member for 9-10 years. Has a total post count of 2,256. Received thanks 280 times, giving thanks to others 6 times.
    Quote Originally Posted by Clive S View Post
    Not sure what you mean here, would you mind elaborating please.. I used the pwm signal from my bob and the https://www.ebay.co.uk/itm/111654184682 to convert it to 0-10V isolated for the spindle driver board.
    Does that board isolate the PWM in from the 0-10V output?
    I'm not sure if the 0-10V output from the DDCSV/RMHV will be compatible with that board. It would depend on if that board is simply relying on referencing the PWM voltage (should be fine), or measuring the actual PWM.

    Actually, I've just checked the spec of a DDCSV, and it states the spindle output can be configured as a PWM, instead of analogue. I can't find any mention of whether it's isolated though.


    The problem with SCR type drives, is the far more common non-isolated versions have the control wiring at near mains voltage, so your 0-10V source has to be isolated. Denford did use isolated drives in some machines, so yours may have an isolated drive, or your BOB PWM may be isolated. The only guaranteed way to check without knowing the exact board you've got, is to power the controller up, and then measure the voltage between the speed control terminals and ground (or neutral/0V).
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

  7. #27
    m_c's Avatar
    Lives in East Lothian, United Kingdom. Last Activity: 4 Hours Ago Forum Superstar, has done so much to help others, they deserve a medal. Has been a member for 9-10 years. Has a total post count of 2,256. Received thanks 280 times, giving thanks to others 6 times.
    Quote Originally Posted by Chas Ixion View Post
    Your right the RMHV and DDCSV are more or less the same.

    I'll use a pot connected to the sprint board for speed control for now.

    After a bit of digging on the internet and head scratching I *think* I've figured out why the speed control was set for 50v. I think that the 50v is the voltage from the tacho at max speed rather than the max output.

    But worried about your comment regarding the motor failing taking out the speed controller, what tests can I do on the motor to establish if its good or not?
    Have a read of the manual for setting the pots. Plus I think there may be posts over on the Denford forum somewhere where the Denford guys give a few pointers for setting the drive.

    Generally carbon dust builds up, causing ground leakage, and/or shorting between windings. However the motors are not the easiest of things to dismantle to clean properly. I damaged the tacho trying to get mine apart, but then I was more interested to see what was in it, as it was already destined for the skip as I upgraded to a servo spindle.
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

  8. The Following User Says Thank You to m_c For This Useful Post:


  9. #28
    Does that board isolate the PWM in from the 0-10V output?
    This morning I checked the voltage between 0-10V and earth about 200V and between PWM and earth 1.5V so it isolates the two.

    Click image for larger version. 

Name:	Control box.jpg 
Views:	35 
Size:	419.5 KB 
ID:	25338Click image for larger version. 

Name:	pwm_board.jpg 
Views:	31 
Size:	207.1 KB 
ID:	25339
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Control box.jpg 
Views:	28 
Size:	420.1 KB 
ID:	25336   Click image for larger version. 

Name:	pwm board.jpg 
Views:	26 
Size:	366.4 KB 
ID:	25337  
    Last edited by Clive S; 18-01-2019 at 11:31 AM.
    ..Clive
    The more you know, The better you know, How little you know

  10. #29
    m_c's Avatar
    Lives in East Lothian, United Kingdom. Last Activity: 4 Hours Ago Forum Superstar, has done so much to help others, they deserve a medal. Has been a member for 9-10 years. Has a total post count of 2,256. Received thanks 280 times, giving thanks to others 6 times.
    Quote Originally Posted by Clive S View Post
    This morning I checked the voltage between PWM and earth about 200V and between 0-10v and earth 1.5V so it isolates the two.
    Good to know.
    Although I assume you meant to have those two voltages the opposite way around? ;-)
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

  11. #30
    Good to know.
    Although I assume you meant to have those two voltages the opposite way around? ;-)
    Well spotted. I have edited mine would you mind editing to save confusion for others.
    ..Clive
    The more you know, The better you know, How little you know

Page 3 of 4 FirstFirst 1234 LastLast

Similar Threads

  1. FOR SALE: Denford Starmill ATC
    By andy_con in forum Items For Sale
    Replies: 1
    Last Post: 14-02-2016, 09:16 PM
  2. Denford Starmill ATC
    By andy_con in forum Marketplace Discussion
    Replies: 0
    Last Post: 09-02-2016, 11:01 PM
  3. FOR SALE: Denford cnc
    By john legge in forum Items For Sale
    Replies: 4
    Last Post: 17-03-2013, 10:18 PM
  4. WANTED: Denford Triac
    By edwardsjc in forum Items Wanted
    Replies: 13
    Last Post: 20-08-2012, 07:17 AM
  5. Denford Starmill
    By Phil Gravett in forum Computer Software
    Replies: 6
    Last Post: 27-05-2009, 11:05 AM

Bookmarks

Posting Permissions

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