I have a 2 pole NC E-stop that I want to wire into my system for safety. I am using a BOB from DIYCNC which is their PCPPS-3PS (power save) and their driver 25PS model on all three axi'. They can be viewed at www.diycnc.co.uk. for layout and Pdf on information I am using a regulated 24V PS with 3 lead points. So what I am asking is where is the best place to wire in the E-stop.

Wiring between the Mains plug and the power supply ensures that power is shut off when I hit the switch and allows me to wire the limit switches to the board and keep them as separate controls (personally a good idea in my book). The E-stop has one 2NC switch in it and space for a second one if need be. Wiring a second one in would allow for information going back to the BOB, but if the E-stop is before the PSU why would it be needed as that seems a bit too redundant to me (still learning, if there is a reason please explain).

So, any and all help or input would be helpful diagrams would be greatly appreciated as tend to be a visual person (though if given good reference points can figure alot out).

Michael

Hi Michael,

I've been through this recently as well. The correct way to wire the Estop is such that it would cut off the power to all the motors of your machine. Also, it is not a good idea to cut the AC side of the of the motor power supply. You have to cut the DC side and switch in a power resistor to discharge the capacitor.

Also it is a good idea to notify Mach3 when Estop has been hit. So in my setup the Estop also cuts the 5V going to the BOB enable terminal, which is hooked to pin 10 of the PP.

Daniel

Be careful,
I read somewhere (might have been in the gecko manuals) that the DC side of a power supply should never have a switch of any kind, or it WILL damage your drives.

Fernando

Thanks Fernando,

You are correct, now that I read my post again I see that I messed it... one should cut the AC side and switch in a resistor across the DC leads to discharge the resistor.

Daniel

I do similar.  2 pole NC E-stop.  One side connected to AC, other side connected to BOB.  I also using a latching relay for AC as belt/suspenders, so when power comes back on it all doesn't just fire right up.

and yes, it is Gecko that says do **not** switch the DC side.  First question they asked me when I spoke with tech support on the phone for warranty repair.

Thanks for the information folks as have set up the E-stop on the AC side of the PSU and going to get a second 2 pole NC to put in the box to wire to the BOB.

Michael