E-STOP Circuit - will this cause any problems?

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Originally Posted by birchy

K1 is the 24V DC contactor. All the safety stuff will be run from the 24V DC supply, so the E-Stops will be 24V and NOT 240V. I've not yet drawn the latching circuit. The above drawing is only for the AC side of things and doesn't show any E-Stops.

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Ok I will let you off this time :beer:

Birchy thats the safest way to do it especially if you are going to have a hand held control box at any time.

Damn Andy beat me. Need to type faster.

FWIW, I work in engineering and have built many machine control panels over the years, so am familiar with standard conventions. However, CNC conversions are new territory and I'm a little concerned that I might blow a drive card or something if I break the wrong circuits on an E-Stop.

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Originally Posted by audioandy

Yes you are right it's not complete, I have assumed that K1 and K2 are the E Stop N/C contacts, no doubt birchy will be along shortly to clarify.

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I didn't think anybody would be that Stupid Andy and also like GOBY presumed it incomplete.!! . . But suppose I should know better Esp after Seeing first hand the Strike time Bomb.!!

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Originally Posted by audioandy

Yes you are right it's not complete, I have assumed that K1 and K2 are the E Stop N/C contacts, no doubt birchy will be along shortly to clarify.

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As I said previously, K1 is the contactor. Terminals (1) and (2) are N.O. contacts that will switch the L and N when the contactor is latched following a reset. The latching circuit will obviously drop out if an E-Stop is active. BTW, there aren't any N.C. contacts on the drawing I posted...

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Originally Posted by birchy

As I said previously, K1 is the contactor. Terminals (1) and (2) are N.O. contacts that will switch the L and N when the contactor is latched following a reset. The latching circuit will obviously drop out if an E-Stop is active. BTW, there aren't any N.C. contacts on the drawing I posted...

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No but you mention them in your post, my fault for assuming!

Birchy I take it that your control pcb does not have estop contacts?

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Originally Posted by Web Goblin

Birchy I take it that your control pcb does not have estop contacts?

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It's a PCPPS V3.0 board. Doesn't appear to have any E-Stop contacts on it. My thinking is that if I kill all the AC devices, then the 50V supply to the steppers will also be killed which should be as safe as it can get?

It would stop the machine but you would lose position and not be able to restart the job from the same position easily. I dont have any experience with this pcb but I would think that one of the inputs would be able to be configured as a estop sense so that the software can recognise an estop signal.

Must admit I hadn't really considered maintaining position in order to restart as I assumed that an E-Stop would be in emergencies only because something had gone drastically wrong. Would it not be more accurate to re-zero the tool because it would most likely overrun slightly when the E-Stop is activated? Plus a tool breakage would probably require manual movement of the Z-axis in order to replace it.