Plasma trigger wiring

[leggman]

I am using a cut 60 chinese plasma cutter and I need to know how to wire the cutter to come on. I am Assuming the switch/trigger wires go to a pin on the breakout board maybe with a relay?
Thanks

[sawdust1]

I found a wiring diagram inside the cover of my miller. You might look there.

[acourtjester]

Here are 2 different BOB board with relays on them if yours don't have a relay you may need to find the pin out either +5 volts or ground for an external relay coil to trigger the torch. One uses pin 9 for output #1 the other uses pin 16

relay.jpg

relay 2.jpg

[leggman]

I have some bosch 12volt automotive relays laying around. With a 12 volt power supply I could trigger a relay or would it be better to find a 5 volt relay?
I am using the longs bob that came with my motors.
I have a touch off switch built into my z axis but right now it's wired into the limit switch loop. I still need to learn how to make that work?

[acourtjester]

I think a 5 volt relay would be better to switch the 12 volts to the relay.
with your touch off switch make sure the limit/home switch loop includes the Z home pin on the BOB.
Mach treats the tripping of a switch as to what you are doing. If moving to a home (touch off is Z home in the G-code) the switch will tell mach its home. If not moving to a home any other tripping of any switch will act as a limit and stop movement.
The difference between home and limit is a home will back away and not act as an error and continue to do other things. Limits stops movement and must be reset.

[acourtjester]

A little clarification if the 5 volt relay has a good contact rating just use it by itself (they sell them at Radio Shack).
And by touch off I assume you are talking about you floating head switch, if you are talking about ohmic sensor hook that alone to the Z home pin.

[leggman]

I have a floating head switch but at the moment it's hooked up in the limit switch loop. I checked the voltage at the trigger connector and it was 1.8 volts

[leggman]

Just purchased some 5volt relays on amazon
http://www.amazon.com/uxcell%C2%AE-240V ... ge_o01_s00
hope this will do it

[leggman]

So I guess I should make the floating head switch a separate wire that would go to the Z home in my input settings? it sounds confusing but I think I have the idea. One wire to ground on the breakout board and the other wire to say pin 16 on the breakout board.

[leggman]

So I guess I should make the floating head switch a separate wire that would go to the Z home in my input settings? it sounds confusing but I think I have the idea. One wire to ground on the breakout board and the other wire to say pin 16 on the breakout board.
For the trigger wiring I will use a wire from the trigger connection on the machine to the NO (normally open) side of the relay and from the ground on the relay back to the machine, then on the coil run one side to the ground and the other side to a pin on the breakout board which will be set to trigger the plasma torch on.
So theoretically when the torch gets the code to come on it will send 5 volts to the relay coil closing the contacts making the open circuit a closed circuit and triggering the torch.

[acourtjester]

the wording is odd M5 sends +5 volts (pin 16) to the relay that closes the contacts on the relay to fire the torch
When and if you get a ohmic sensor that needs to be a separate wire to the torch shield and to the metal.

switch wiring AB.jpg

switch pos.jpg

relay.png

[leggman]

Awesome, Thanks Tom.

[leggman]

In testing the breakoutboard for voltage I do not get 5 volts when I turn on the torch in mach3. I might have to switch breakout boards but I really don't want to

[leggman]

I changed breakout boards and now the plasma toggles off and on. Getting closer to cutting plate.

[leggman]

I am getting so close but have hit a new snag. When I turn the torch on manually (f5) It comes on but I lose motor control, The keyboard and mouse die and I have to do a hard shutdown to get everything back up. Everything works fine before that and I do have the water pan grounded to earth via a heavy copper wire and a 8 foot ground rod behind the shop drove into the ground.
I can see the top of the mountain but I just can't get there.
Thanks for any advice that might be out there.
Dave

[sphurley]

And that is the big reason not to use Chinese Plasma cutter. It is likely a high voltage start machine. The use of Ferrite core suppressors is a start.
"Ferrite Core 1/2 Cord Noise Suppressor" on Amazon.
Keep the power for the plasma as far away from the computer as possible. Keep the torch cable away from any stepper cables, homing/limit switch wiring. Use shielded cables on those where you can. Keep cables short, never coil them up and bundle them.
Keep the table cable short and away from anything.
Those are all a start. You might even put the PC/controller on a UPS/Filter to help.
It's been done before and worked.

[leggman]

I went with the cut 60 because frankly that was all I could afford. I built my own table because well, same reason. Of course I would rather just buy a plasmacam and have all the buttons and whistles but there again is the money thing. I had hoped to make enough money with the homemade table to afford a storebought table someday.
I like the noise suppressor idea, how many do I need and where should I put them? Thanks again. Dave

[sphurley]

They are cheap so put one or more on each axis cable close to the controller, the parallel cable should be good quality and as short as possible and put one or more on both ends of it. If you are using the USB port for power put a couple on it and also the limit switch cable. The relay can cause it's own issues from the relay coil but that is usually when you would de-energize the relay.

ENG_CS_13C3311_AppNote_0513_Application_of_Coil_Suppression_with_DC_relays_13c3311.pdf

It is still good practice to put some kind of protection diode on it unless the controller has one built in. The relay would be more likely to damage the controller than cause the shut down issues you are having.
https://www.youtube.com/watch?v=c6I7Ycbv8B8

[leggman]

I have not bothered with my plasma table build for several months because I hit a major snag.
I have a homebuilt 4 x 4 table using the longs motors kit with the longs motors, power supplies, and drivers.
I have it moving like it should finally but when I trigger the torch on it kills the keyboard and the mouse.
The other day I had it running with NO torch even hooked up to it and I saw some sparking between the torch tip and the sheet of metal on the table?
Do I need some sort of dedicated ground from my motors to the chassis?
I know I am trying to use a cheap Chinese cut60 plasma but it's all I have until I can sell some body parts to get a hypertherm 45.

[acourtjester]

The motors are not directly grounded to the chassis, you should have a shielded cable for the motor wiring and that (shield) is attached to chassis ground only at the controller end. This is for noise reduction only.
You said the torch was not hooked up do you mean the torch lead was not attached to anything?
There should not be any sparking from the torch tip to the metal if there is no connection.
From what you are saying there must be a wiring error as the keyboard and mouse should not have any problems when you hit F5.
What are you using to power your BOB board. You said you are using Long motors electronics, are you using the BOB board they supply or another one?

[leggman]

Plasma cutter is not attached at this time. I was just running the table to make sure it still works when I saw the sparking. Very small sparks going from the torch tip to the metal. I will try to make a video soon

[acourtjester]

If you have a multi-meter I would check to see if you can measure any DC or AC voltage between the tip and metal. The torch cable not connected is just an insulated wire and should not have any voltage of any kind. If you measure anything that will help you find out where it is coming from by disconnecting things.