Secondary switch for air nozzle

[Matt@RFR]

So I've wired in a solenoid to be switched by the M21 relay to make my own air-blow and it works just fine using M51/M61. The solenoid requires .3 amps, so I've directly wired it to the relay. What I would like to do now is to wire a momentary push button switch so I can manually operate the air nozzle if M51 is not active, but need help with the wiring.

I was thinking that all it would take is to run a hot leg from the GFI outlet (where I'm getting power for the relay/solenoid in the first place) to the switch. Then from the switch, connect it to the wire that is coming from the M21 relay, going to the solenoid. Does it matter if I use the nuetral or hot leg?

I'm comfortable with wiring DC stuff (automotive), but not so much with AC, and luckily I know enough to know when I don't know.

How would you guys go about wiring in this secondary momentary switch?

[Geof]

I am not going to tell you how to wire the second push button switch because my (not so ) humble opinion is that wiring things with line voltage is too hazardous.

I will agree that the Haas manual says the contacts on the dinky little relay on the board are rated for 120volts AC and 3 amps. But if you have wired through the DIN socket that this relay is connected to you are putting lin voltage through something that is not intended for line voltage (I think).

You may be using a GFI outlet which gives you ground fault protection but the current protection is going to be a standard 15 amps. If something shorts the solenoid, or if you did install a manual switch and something went wrong there, you are going to smoke your wiring. The wire gauge going to the relay cannot take 15amps, neither can the relay of course, so you are running the risk of smoking your board.

We have several machines operating external equipment through the user M relays but I designed interface boxes so that the relay inside the machine is only switching 12 volts. This relay operates a larger relay rated at more than 15 amps that supplies an outlet on the back of the interface box so we can run any manner of large or small devices. The boxes have a manual override but it is switching the 12 volt circuit.

Maybe I am being too cautious and will get dissenting opinions.

[Matt@RFR]

Hmm, the manual and what I've read here say I'm ok, but I would rather err on the side of caution. Could I simply put a 1A inline fuse in the wire going to the relay?

Where did you get 12V from?

[Geof]

Originally Posted by Matt@RFR ..... Could I simply put a 1A inline fuse in the wire going to the relay? Where did you get 12V from?

Yes you should fuse the relay at lower than its capacity.

The 12volts is from a regular 'Wall Wart'.

[HelicopterJohn]

Hi,

Why not operate it with a Heinrich Air Control Foot pedal? I have one that is hooked up to my PCOOL nozzle so you get the programmed tool height advantage. That way you won't have to worry about all the electronic stuff. I can send you some pictures if you are interested. I have posted them here on the form.

I also have the the same system you have for the M21 but powered mine with a 24 volt AC wall wart like Geof suggested. I plugged it into the GFI protected outlet on the back of my TM-1P.

My latest adventure is a programmable air/coolant rocker switch. I can use coolant utilizing M08/M09 or flip the rocker switch and get programmed air blasts instead of coolant. The timer unit has 2 pots on it. You can adjust the amount of time in between air blast with one pot and also how lenght of time the air stays on with the other pot. I may also create an option where you can get both the programmed air blast and coolant at the same time. I even posted a little video on this for your amusement in another thread.

Just some things you might be interested in.

John

[crabbass]

Would you guys take some pictures of your electrical cabinets and post them in this thread? Geof, I am interested in your interface design. Would you be willing to share a pic? Thanks for your input.

[Geof]

Originally Posted by crabbass Would you guys take some pictures of your electrical cabinets and post them in this thread? Geof, I am interested in your interface design. Would you be willing to share a pic? Thanks for your input.

I have no problem with pictures or a circuit diagram other than time. You might have to wait for a couple of weeks because I am gearing up to leave on a vacation on Friday; I actually have to complete some stuff for the business before then.

Probably three weeks I guess because I am not back until May 9. I will still be online most days but many thousands of miles from home.

[Donkey Hotey]

I must be missing something here. The relay has power coming in and it switches that power on and off, right? So why not just wire a switch across the same two relay terminals? If you push the button, it does the same thing as the relay. That stuff is 24VDC, isn't it?

[Geof]

Originally Posted by Donkey Hotey I must be missing something here. The relay has power coming in and it switches that power on and off, right? So why not just wire a switch across the same two relay terminals? If you push the button, it does the same thing as the relay. That stuff is 24VDC, isn't it?

Correct, except that Matt is using 120volts AC across the relay so you would need a switch at the same voltage, so all your wiring should be typical AC circuit standards, but the wires to the relay inside the machine are not, which is why I expressed caution and complicated things and wrote an almost incomprehensible sentence at which I am good.

[Donkey Hotey]

Ahh...so this isn't factory wiring? I thought all this stuff was done at 24V, not 120V.

[pit202]

Why haven`t you connect the air blast to the air blast port on the IO board ? The benefits are :
- you just plug to the solenoid and run ( no need for external power supply )
- you don`t use any of Mxx relays ( I have only two and they are used for probes )
- you can switch the air blast on and off from keyboard ( shift coolant )
- you can program it from M codes ( M83 and M84 ) and you can turn it on for 0,5 sec. M83 P0.5

I have upgraded my TM in an air-oil blast , and now I sometimes do not use coolant even for alu
__
Peter

[Matt@RFR]

Greg, I do not have the air nozzle option installed on the machine. This is all my own doing.

So, if I'm understanding you correctly Geof, I can run pretty much any voltage I want. If that's the case I'll just use a 120VAC - 12VDC transformer and wire the damn thing just like I would a headlight circuit in a car. Could I tap off the GFI terminals to go to the transformer? That would still allow one spot in the GFI for the 120V going to the larger relay for the 120V solenoid that I allready have.

John, no offense intended, but your way is just too ineficient for me. I don't want to be stepping on a pedal...I want to be off programming another job while the machine is running by itself. I also don't want to be changing any kind of plumbing to use M8. I will, however, be stealing your idea for the airline mount on the programmable coolant nozzle. Thanks for that.