Design/ideas for a laser tube hour meter?

[Timothy Kamp]

I'm looking for a way to monitor the actual hours a specific CO2 laser tube has been cutting. Now that I have 4 machines that run a LOT, I think I may be able to start providing some really detailed research about how much power these tubes are outputting at set hour marks. I just checked out a laser power meter on my new 130w tube and before I start cutting round the clock with it, I want to put a meter on it. I know some machines have built in hour timers, but too many of them are tied to movement of x/y or even powered on. I'm using the X7 AWC708 controller, which has a few outputs, one for when the machine is moving and one for when the tube is firing, but when I'm doing big engrave jobs often the tube is switching on and off very rapidly. Any meter design needs to have some type of hysteresis to count the tube as "on".

As a side note, a few months ago I hooked up a relay and a air solenoid to dabble with saving compressor wear and tear by switching the air on and off as the tube fired, but it cycled too much and it failed to keep the nozzle and lens clear of debris. One of these days I'll switch the relay from the laser output on the controller to the xy movement output, but that's neither here nor there.

I've been thinking of trying to do something custom with an arduino, but didn't want to reinvent the wheel. Anyone have any great fixes/solutions to tracking laser tube time?

Here's a shot of me testing a 130w laser tube with the power meter. It's at 28ma and outputting 134.2w, which is right on target. I'm going to install this into one of my big 1800x1200 machines (picture #2) to replace a SPT tube that failed due to overheating as a result of me being an idiot.
20160227_131933.jpg
1800x1200machine.jpg

[David Somers]

Timothy,

I don't have an hours meter on my Chinese laser and haven't considered adding one other than to speculate what you might do if you wanted one.

I did add a mA meter to mine so I can monitor the power provided to the tube at various power percentage levels. Could you add an hour meter to that side of the tube so that it counts time as the tube fires, just as the mA meter activates as power is applied to the tube?

Of course, I cant give you details about how to do this. That might actually be useful. But that would seem to be the place to put a meter to my electronically feeble mind.

Dave