Thread: routercnc_MK3

Page 6 of 12 FirstFirst ... 45678 ... LastLast
  1. #51
    Based on a discussion I was having in another thread (but didn't want to hijack) my plan is to remove power directly from the drivers in the event of an e-stop via relays.

    But as the steppers a likely to be moving then is this is problem for the drivers? I'm sending an e-stop to the BOB at the same time so the motors should be in the process of stopping.

    Would it help if I added a capacitor across the relay coils to slightly delay driver shut down prior to the motors coming to rest - just a few milliseconds? Or am I worrying over nothing?

    Does anyone else remove power to the drivers using relays in the event of an e-stop?
    Building a CNC machine to make a better one since 2010 . . .
    MK1 (1st photo), MK2, MK3, MK4

  2. #52
    Quote Originally Posted by routercnc View Post
    Or am I worrying over nothing?

    Does anyone else remove power to the drivers using relays in the event of an e-stop?
    Yes your worrying over nothing.!!! . . . If you remove signals so no pulses are still getting thru while caps drain then just turning off the power will be enough and motors will come to stop quick enough.

    Edit: If you do want to go a little OTT then have e-stop turn off drive Enables so motors are still under torque and stop quick then remove power second or two later using a timer relay.!!
    Last edited by JAZZCNC; 17-04-2015 at 09:24 AM.

  3. #53
    Hi Dean

    In my layout (see post above) my relays are AFTER the PSU so there are no caps to drain and the drivers loose power immediately. So I either leave it, change to a relay BEFORE the PSU on the mains side which I think is what you are referring to, or add delay / capacitor across the existing driver relays on the DC side to hold them closed for a few milliseconds. Hope this distinction makes sense.
    Building a CNC machine to make a better one since 2010 . . .
    MK1 (1st photo), MK2, MK3, MK4

  4. #54
    Well my way is to remove power by dropping out a contactor to transformer and send signal to control informing about e-stop so halting pulses.!

    But in all honest your setup won't be a problem unless you intend traveling at high velocity and have a heavy gantry. So if you have it wired then wouldn't worry.!
    Last edited by JAZZCNC; 17-04-2015 at 05:52 PM.

  5. #55
    Ok, good to know thank you. Gantry is pretty light and feedrates aren't that high.

    Capacitor mount brackets arrived today so roughly laid it out on the aluminium plate. Plate will be trimmed off just after caps, and before MCB.

    I noticed that the toroid 2x24V AC cables are a much heavier gauge than the 240V AC cables so I'll match that heavy gauge with the DC cable out of the rectifier and over the caps.
    Click image for larger version. 

Name:	PSU_layout 005.jpg 
Views:	139 
Size:	346.3 KB 
ID:	15161

    It's a bit bigger than the blown SMPS it replaces but should still just about fit in the cabinet, top centre:
    Click image for larger version. 

Name:	box_v3_i.JPG 
Views:	138 
Size:	114.2 KB 
ID:	15162
    Building a CNC machine to make a better one since 2010 . . .
    MK1 (1st photo), MK2, MK3, MK4

  6. #56
    Joined the red and orange together and got 54V AC across the black and yellow, so that is the correct series connection.
    Click image for larger version. 

Name:	PSU_wiring 001.jpg 
Views:	173 
Size:	296.8 KB 
ID:	15163

    I cut the red and orange cables back to leave about 60mm showing, stripped and tinned then ends then soldered together. Heatshrink over the join, then another long heat shrink over the top to finish the series connection.

    Crimped terminal ends on the black and yellow cables for the rectifier. Had a look at the datasheet and the terminal rotated 90 degrees to the other 3 is the DC + output. Diagonally opposite this is the DC - output. The other 2 are AC inputs.
    Click image for larger version. 

Name:	PSU_wiring 003.jpg 
Views:	160 
Size:	310.8 KB 
ID:	15164

    Marked out the holes for the cap brackets, rectifier, toroid and corner bolts and started drilling a few out. Went with M4 tapped on the capacitor bolts. Getting there slowly . . .
    Click image for larger version. 

Name:	PSU_wiring 002.jpg 
Views:	163 
Size:	266.0 KB 
ID:	15165

    The MCB hasn't tripped out yet on the few times I've turned it on (6A type D) but since I haven't connected the capacitors yet that probably doesn't mean much.
    Building a CNC machine to make a better one since 2010 . . .
    MK1 (1st photo), MK2, MK3, MK4

  7. The Following 2 Users Say Thank You to routercnc For This Useful Post:


  8. #57
    Quote Originally Posted by routercnc View Post
    Joined the red and orange together and got 54V AC across the black and yellow, so that is the correct series connection.
    Click image for larger version. 

Name:	PSU_wiring 001.jpg 
Views:	173 
Size:	296.8 KB 
ID:	15163

    I cut the red and orange cables back to leave about 60mm showing, stripped and tinned then ends then soldered together. Heatshrink over the join, then another long heat shrink over the top to finish the series connection.

    Crimped terminal ends on the black and yellow cables for the rectifier. Had a look at the datasheet and the terminal rotated 90 degrees to the other 3 is the DC + output. Diagonally opposite this is the DC - output. The other 2 are AC inputs.
    Click image for larger version. 

Name:	PSU_wiring 003.jpg 
Views:	160 
Size:	310.8 KB 
ID:	15164

    Marked out the holes for the cap brackets, rectifier, toroid and corner bolts and started drilling a few out. Went with M4 tapped on the capacitor bolts. Getting there slowly . . .
    Click image for larger version. 

Name:	PSU_wiring 002.jpg 
Views:	163 
Size:	266.0 KB 
ID:	15165

    The MCB hasn't tripped out yet on the few times I've turned it on (6A type D) but since I haven't connected the capacitors yet that probably doesn't mean much.
    This was the way I joined my transformer from the technical description on the airlink website...

    Neil...

    Build log...here

  9. #58
    Quote Originally Posted by routercnc View Post
    Joined the red and orange together and got 54V AC across the black and yellow, so that is the correct series connection.
    Click image for larger version. 

Name:	PSU_wiring 001.jpg 
Views:	173 
Size:	296.8 KB 
ID:	15163
    Like the Wood.!!. . . . This way you can Bat your self with it when you electricute your self.!. .Lol

  10. #59
    Doh! I've cut the red and Orange back quite short and soldered them together. Can someone tell me if it matters this way around instead of Neil's picture ?
    Thanks
    Building a CNC machine to make a better one since 2010 . . .
    MK1 (1st photo), MK2, MK3, MK4

  11. #60
    Quote Originally Posted by routercnc View Post
    Doh! I've cut the red and Orange back quite short and soldered them together. Can someone tell me if it matters this way around instead of Neil's picture ?
    Thanks
    Doesn't matter.!

Page 6 of 12 FirstFirst ... 45678 ... LastLast

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
  •