Hello Guest it is October 14, 2019, 12:23:03 AM

Author Topic: E Stop and my new VFC and Spindle  (Read 7132 times)

0 Members and 1 Guest are viewing this topic.

E Stop and my new VFC and Spindle
« on: September 27, 2008, 09:51:43 PM »
I'm in the process of wiring up my new VFD and Spindle.  I'll be using a CNC4PC speed control board to provide control voltage to my Chinese VFD.  I think I get how to wire this from the instructions. 

My question is How do I wire an Emergency Stop button so that when I hit the button it stops the steppers AND the spindle at the same time?  The VFD suggests that I E Stop the control voltage on the lead that controls direction/stop.  But if I put the Estop on this, what stops the steppers? 

I'm hoping that Mach 3 has a port or some way of sending stop signal to the VFD stop input as it also stops the steppers. 

Thanks for any help.  Setting up the spindle is a bit of a challenge for me, but I'm leanring alot about Mach, and what options I have to control things. 

Wayne from White Salmon
Re: E Stop and my new VFC and Spindle
« Reply #1 on: September 27, 2008, 10:49:18 PM »
Just connect a switch to any available paralllel port input, and configure it as an E-Stop pin.  Mach will turn everything off when that pin is activated.  Usually, a normally open switch would be connected between the PP pin and ground, so when the switch is pressed, the pin is pulled low.

Regards,
Ray L.
Regards,
Ray L.
Does this send a stop signal to the VFD as well?
« Reply #2 on: September 27, 2008, 11:10:57 PM »
Thanks Kabibble,  that's exactly what I needed.  Does this also send the stop voltage to the relay that controls the spindle on/off/Direction?

I'm guessin it does, but just want to be sure.   

This is good.  I don't have an estop now.  It will be nice to have this increased measure of safety.

Thanks for your help.

Wayne
Re: E Stop and my new VFC and Spindle
« Reply #3 on: September 27, 2008, 11:26:12 PM »
Wayne,

    It turns off everything - spindle, coolant, all drives, and shuts off the safety charge pump, which should turn off everything at your BOB as well.

Regards,
Ray L.
Regards,
Ray L.
Re: E Stop and my new VFC and Spindle
« Reply #4 on: September 28, 2008, 02:14:41 AM »
Just connect a switch to any available paralllel port input, and configure it as an E-Stop pin.  Mach will turn everything off when that pin is activated.  Usually, a normally open switch would be connected between the PP pin and ground, so when the switch is pressed, the pin is pulled low.

Regards,
Ray L.
This is quite dangerous advice. To rely on Mach3 software to control an Emergency stop is very bad practice. The EStop input into Mach3 is just to politely inform Mach3 that an EStop has occured. The "Real" Estop circuitry should remove power from the steppers and the Spindle.

How is an EStop going to work if you press the big red button becaure Mach3 has run amuck. The Estop should remove the primary AC power from the Steppers (Do not switch the DC Side) and the VFD.

Cheers,

Peter.
----------------------------------------------------
Homann Designs
http://www.homanndesigns.com
email: peter at homanndesigns.com
So now what?
« Reply #5 on: September 28, 2008, 10:12:38 AM »
Peter,
 
Thanks for the heads up.  I understand exactly what you mean.  If the software goes awry, the Estop may not work.  That's not really the safety stop that an emergency stop should provide.  I've had a couple instances where the Z axis dived into the spoilboard and Mach reset didn't stop anything.  A non-software Estop would fix that. 

So, my Ascension controller has limit switches that stop the motors and Mach3.  Could I put the Estop button in series with that stuff?  Or am I back to using the software to stop things? 

Also, my speed controller (CNC4PC, sorry) has relays that use a signal from Mach to start/stop the spindle.  Can I wire the same Estop switch to turn off the spindle with these relays?

In general, how should one wire an Estop circuit to shut down both software, spindle, and steppers? 

No small question, I know.  But I'd like to get as real an Estop as I can get. 

Thanks for your input- I'm glad you posted before I got going on the install.

Wayne
Re: E Stop and my new VFC and Spindle
« Reply #6 on: September 28, 2008, 10:16:48 AM »
Wayne,
    I have a CNC4PC C11 breakout board, which has a dedicated E-stop input that de-activates everything on the board - all outputs are turned off, all relays de-energized, etc.  I would have suggested that, but you didn't seem to have the hardware to do it.
Regards,
Ray L.
C11? Will the C6 do this as well?
« Reply #7 on: September 28, 2008, 11:42:57 AM »
Kabibble, no offense intended at all- you gave sound advice with the limited info you had, and I'm grateful.  So, I have the C6 board.  Does it have similar dedicated E stop port?  That would be perfect. 

If it doesn't, can I put the Estop in series with the Spindle on wire and shut the spindle off that way?  I guess I'm imagining the Estop breaking the circuit to ground, and thereby triggering the relay in the VFD to shut off the spindle.   

Can I also take the 'output' of the Estop switch to the limit switch input on my Ascension controller?   Right now, if any of the limit switches are closed the controller shuts down the steppers instantly.  I think its doing this thru the Mach3 software, but I'm not sure.  If I put the Estop switch in series with this as well, it should trigger a stop just like the limit switches do. 

If I do this, wire both circuits to the same Estop switch, will I have interfernce from one circuit to the other- i.e will the operation of VFD relay be affected by the presence of the limit switches and their cabling? 

It must be obvious to all that I'm no electrical engineer.   I appreciate your help to get me to understand this. 

Wayne from White Salmon
Re: E Stop and my new VFC and Spindle
« Reply #8 on: September 28, 2008, 02:24:14 PM »
Kabibble, no offense intended at all- you gave sound advice with the limited info you had, and I'm grateful. So, I have the C6 board. Does it have similar dedicated E stop port? That would be perfect.

If it doesn't, can I put the Estop in series with the Spindle on wire and shut the spindle off that way? I guess I'm imagining the Estop breaking the circuit to ground, and thereby triggering the relay in the VFD to shut off the spindle.

Can I also take the 'output' of the Estop switch to the limit switch input on my Ascension controller? Right now, if any of the limit switches are closed the controller shuts down the steppers instantly. I think its doing this thru the Mach3 software, but I'm not sure. If I put the Estop switch in series with this as well, it should trigger a stop just like the limit switches do.

If I do this, wire both circuits to the same Estop switch, will I have interfernce from one circuit to the other- i.e will the operation of VFD relay be affected by the presence of the limit switches and their cabling?

It must be obvious to all that I'm no electrical engineer. I appreciate your help to get me to understand this.

Wayne from White Salmon

Wayne,
    The C6 is only a spindle driver card, so it cannot effect the steppers and other parts of the system.  You really should have a full breakout board as the interface between the PC and the motor controllers - something like the CNC4PC C10.
   As for the solution you describe, that would have one very serious drawback - the machine would only be disabled for as long as you held the E-Stop button - not good.  E-Stop should be a momentary button that you need only press once, and the machine is disabled, and remains disabled until you explicitly clear the fault.  This could be done by using the E-Stop to open a latching relay - this is one that once de-energized, remains de-energized, even if power is restored, until some other switch is thrown to put it back in the energized state.  This can be implemented with a DPDT relay, and a separate switch to "enable" it, and the E-Stop to disable it.
I still think a good breakout board, with built-in E-Stop logic, is the best way to go.

Regards,
Ray L.
Regards,
Ray L.
Maybe my board does this...
« Reply #9 on: September 28, 2008, 04:50:24 PM »
I have an Ascension 1000 controller from Alan at Custom-CNC.  He's out of biz now, but the product seems to work pretty well.  Its a breakout board with Gecko 201 drives and a power supply.  I wonder if it has an estop capacity that I'm not aware of. 

I do agree that whatever I do can't be a momentary switch.  The Estop I have has a mechanical interloc, so that it locks off until you twist it to release it.  But I have to agree that a relay that requires deliberate action to restart would be best.  I'll work that direction.  This is all very good input, and valuable to others as well I'm sure.

I'll see if I can find out if the board I'm using has an additional relay or can trigger a relay in this fashion.   Wish me luck finding some help with the Ascension controller. 

Thanks for the valueable insight.

Wayne C