Timed pause?

[fatal-exception]

Is there any type of plugin or some other way to tell mach 3 to pause and shutoff the plasma torch after a certain amount of time? The reason I ask is that my compressor can't keep up with the plasma machine. It would be handy to have the software automatically pause and wait for the compressor to pump up.

Currently, for larger parts, I feed hold the job, then shut off the torch manually. To resume, I turn on the torch then quickly hit the run button. There has to be a more sophisticated way of doing this...

Thanks,
Paul

[hanover owing]

what cam program do you use sheet cam has pause option at the end of each cut

[fatal-exception]

Ok. I see where that setting is, but this doesn't really help if a single cut path is very long.

Paul

[Sunmixed]

It's possible to modify the M03 Macro for adding a pierce counter. When the pierce counter reaches a specific value, say 30, M03 Macro will trigger a new script that has your variable timed pause. That's the best Mach 3 can do.

[Torchhead]

Actually you can track the distance moved in SheetCam, the number of Torch On events or both. There may also be a way to track cut time. I know you can do time tracking in a plug-in in MACH (we do that in our Spindle Speed Plug-in for total spindle time) but I don't know how easy it would be in a macro..

The poor mans way is to write a short code snip in SheetCAM that lifts the torch and does either a long pause (G04 P 300 = 5 minutes) or an M00 (pause until you get a Cycle start) and insert it in your cut process list.

TOM Caudle
www.CandCNC.com

[Pandinus]

If the compressor can't increase pressure while the plasma is on it is definitely too small.
I am currently cheating by using two compressors on separate 120V circuits until I buy a big one. The bigger one will barely keep up, but it can't run 100% duty cycle anyways so I have the small one tuned to turn on just after the big one and it turns off just before the big one. So if the pressure drops slower than my plasma the main one turns on and pumps back up on its own... if the plasma is on the main turns on but still drops a couple of pounds and the auxiliary turns on and they both regenerate pressure... not ideal but better than nothing

I have it in my mind to make an electronic pressure control that will monitor the drop and if the tank is draining too fast... IE the plasma is running, the compressor starts right away... maybe even start the compressor if/when the torch fires.

In your case here is an idea... how about route the torch on and arc ok signals through relays connected to the compressor... when the compressor pressure switch trips it would interrupt the torch on and arc ok.... Mach would stop when arc ok disappears and start again when arc ok returns...might want to use some sort of a time delay of a few tenths of a second switching the torch off as I'm not sure how fast Mach actually stops movement with the arc ok signal...

End result would be the plasma stops while the compressor is pumping your tank up again... Auxiliary tank would cut down on the stops as well but the refill time increases...

Most compressors are not meant to run anywhere near 100% duty.. I think I heard 50% is the max you want to run unless you have a machine meant for 100%... The plant I used to work at had rotary screws... man those could put out hundreds of CFM all day long...
If you do upgrade the compressor you should go with at least double the CFM that your plasma requires to get you below the 50% duty cycle rating. My biggest hold back on that one is needing another 240V circuit for the compressor as my plasma can't share the load on its 30 amp branch... I'm not sure how stealing the dryer outlet while I'm cutting will go over... lol ... Well I figure its not worth upgrading the thing unless it will actually pay for itself anyways.

[Pandinus]

PS... you could also use toggle switches to interrupt the arc ok and torch on signals. You could also write a BRAIN that monitors an input and stops the movement and torch with the time delays for torch on and off in it... so many ways to skin this cat