Epilog Legend interlock

I repaired an Epilog Legend EX. It had a fire, works great now. The interlock on the Epilog is magnet based and set up so the laser stops when the lid is opened. This is a safety issue.
I always thought that the magnet completed the circuit and when the lid was closed, the circuit was closed and the machine would run.

Since my repairs, I see the two sensors near the lid, but the laser does it's works lid up or down.

Recently I had someone use the laser and had a flare-up. They lifted the lid and the laser did not stop, a flame up occurred and the lens cracked.

So now I am motivated to figure this out.

Epilog is understandably vague on what to do as this is a safety issue and liability.

Other than looking for shorts or opens in the wire, are there any ideas on how to debug and get the interlock to work. We were even thinking about putting a toggle switch to set off the sensor to stop the laser using the sensor wires present.

Am I on the right track, or does Epilog do something tricky.

Maybe the sensor melted in the closed position? Does anyone know the proper operation?

thanks,

You seem to have figured out the most probable causes yourself.

I will have a look at my machine tomorrow morning to see what sort of sensors they fit (I think they are reed switches as I think that there is only two wires to them, but they might be solid state hall effect thingies) and let you know.

Hi Andrew

If the switches are reed switches it's possible that they were damaged in the original fire. Many magnetic switches you see now are Hall effect, so there are no moving parts. I would check continuity at the switches first and go back from there.

The switches are definitely the reed type (they don't need power to operate).

The switches are ON when the door is closed and OFF (open circuit) when the door is open, so nothing tricky or obscure there.

The switches (all four of them) have connectors nearby, so it is easy to unplug them to check if they are operating properly.

A further thought -

The lid switches are NOT an emergency stop system : they merely turn off the laser itself.
If the red-dot pointer was on, that continues to shine with the lid open and the head will continue to raster or vector until you press the "Stop" button, turn the machine off or the job "finishes".

So it could be that your machine is actually working correctly - are you sure that the laser stayed on when the lid was opened?

yep you are correct, the laser disengaged but the system runs until the next object and stops if you hit the STOP. That was SOP for flame ups before the fire - to open the lids and hit stop. The same guy who used the laser before the fire is using it now - No not the guy who caused the fire and sprayed ABC fire extinguisher on it. not around any longer.

Where are all four switches, I see two in the front sides of the lid and I know this laser very well.


As a side note. We just replaced the lens with an Epilog lens. The previous lens was a brightobjects.com lens. There is ALOT more power using the Epilog lens. Whodathunk.

Thanks for your help. It was good to know if they were NO or NC relays. There was no writing I could read on them.

Two switches near each other under the front right-hand side of the see-through lid.
One switch each side on the front of the unit for when the whole metal part of the lid is raised.

(Mine is a 32EX - I have never seen a 24EX, but assume that the construction is similar)

One thing I noticed on my Epilog. The magnets/switches seem to be independent. I had one magnet (I think it was the left one) fall out of the lid, and and it made no difference at all. As a matter of fact, it was probably gone for months before I noticed and the machine kept right on working. So, I guess both switches have to be disconnected (i.e. the lid opened) before the beam shuts off, and you only need one magnets for to fire..

That seems VERY strange, it should be an EITHER/OR type scenario that should trigger the laser to shut off.
Or at least that is how I wire up interconnect/safety switches like that.

There are some mag switches that have both NO and NC contacts as well as COMmon.
These are used primarily in home/business alarm systems to detect when someone has tampered with the door switches or wiring. If it's NC, then someone shorts it to bypass the alarm. If it's N.O. Someone cuts it to bypass the alarm. But when wired to both, either a short or a cut, will be detected by the alarm panel (at least in theory).

A DMM or continuity tester should be able to verify the wiring and if mag switches are operating correctly.

As a test, I'd disconnect it at the circuit board and the laser should NOT fire.
If it does fire (ignoring red dot pointer), then something may be wrong.

If it gets to the point where the beam does not shut off or turn on when I open or close the door (if you have to restart a uncompleted job, you can run with the red dot until you hit the spot you want the beam on, then close the door to start it) then I will worry about it, until then it creates no problem..

It's all good, I just wish they would PAUSE everything, and not just the laser from firing when opening the door.

My stop button will stop the everything at the end of a pass for raster, or the next node on a vector.. But, sometimes the next node can be a fair distance away before the head stops, but the open door will shut off the beam instantly.