Powermax 85 question regarding mach3+bob+relay+torch start

[hayaome]

Hi friends,

I'm quite new to cnc/plasma, but had no way as do a "crash course" into the subject. So the questions start to rise

System is homemade and controlled by Mach3.
BOB is http://www.routoutcnc.com/25WayD.pdf
Power supplies are 2xPS407 (42vdc, 280W)

Torch is mechanical, and right now i'm triggering torch ON manually with original switch what came with Powermax. Simple two wires connected to the machine.

Confusion started when the need came using mach3 to trigger the torch on/off. Have done lot's of reading here but it's still not clear to me what kind of relay to use (had no experience before with electronics that much, but everybody gotta learn sometime I understand that the solution is quite simple but with no background info i better be careful with all..

Found C8 relay board from cnc4pc.com, will that do the trick? Of can i buy a nice little solid state relay myself and make the connections..

Maybe there something i forgot to .. pardon me.
Any help is really appreciated,
Thanks in advance,
Marko

[selrahc]

FYI, Pin 1,2,3,4,5,6,7,8,9,14,16 & 17 are output signals, Pin 10,11,12,13 & 15 are input signals, and Pin 18-25 are ground connections.

Pin 2,3,4,5,6,7,8,9 are output signals with slightly higher current than Pin 1,14,16, 17.

If you would like to buy your own solid state relay, I would suggest using Pin 8, since I would guess that you're using 3 Axis for your Plasma CNC, and A Axis is not used.

1. Wire up Pin 8 and Ground Pin to a AC Solid State Relay Input.

2. Connect output end of AC Solid State Relay to 120VAC Relay
(suggested relay: OMRON MY2 120VAC Relay or equivalent,
Pin 13 and Pin 14 of MY2 Relays are trigger pins).

3. Connect MY2 Relay's Common(COM) and Normally Open(NO) to Plasma start signal.

I'm not sure which Hypertherm you're using, however all Hypertherm manuals contain information about plasma start signal wiring so that shouldn't be of a problem.

Be very careful while connecting solid state relays, do not confuse input wirings over output wirings, else you will have AC striking your motherboard.