Laser has a hiccup???

[Chad Fitzgerald]

Lately, last month or so, my laser will "misfire". Only occasionally, always at the start of the run (almost the start, starts engraving then it misses a small area to be engraved, then continues on just fine.) It has happened on different area of the table, different settings, different files. the only thing consistent is that it is only occasional, and it is within the first half second of the run. I run it a second time to let it engrave the missed area and then stop it when its done with that small area. So i have been getting by but a pain.
Anyone have any ideas?????????
Thanks Chad

[Bill George]

Lately, last month or so, my laser will "misfire". Only occasionally, always at the start of the run (almost the start, starts engraving then it misses a small area to be engraved, then continues on just fine.) It has happened on different area of the table, different settings, different files. the only thing consistent is that it is only occasional, and it is within the first half second of the run. I run it a second time to let it engrave the missed area and then stop it when its done with that small area. So i have been getting by but a pain.
Anyone have any ideas?????????
Thanks Chad

Could be the tube or power supply or any number of software issues. Can you watch the MA meter to see if it is showing current draw right away when you start the cut?

[Chad Fitzgerald]

I dont know what "MA meter" is. Is it on the laser????
Also, I dont know if I would be able to catch it because it doesnt happen often.
Chad

[Richard Rumancik]

Chad, if you notice Bill's signature line he has a Chinese laser system. These use the glass tubes and high voltage power supplies for the tube. In order to give an idea of power output, these tubes have a milliamp meter (mA meter) on the input side of the laser tube, to measure current to the tube. The output of the tube will be a function of this input current - it might not be linear but nonetheless it will give the user an idea of power output.

Bill was suggesting you watch that to see if the input current is dropping out momentarily. But your laser does not have one as it uses different technology. So that won't work for you.

It could be a sign of something failing but it would be hard to pin down. Have you communicated with GCC? Does this only happen when to start the machine up from cold? Or does it re-occur various times after the laser has been running?

If it only happens on the first run of the day I would probably not overreact and replace parts. It does not sound like it is going to greatly affect your production at the moment. I would probably live with it and monitor the situation before replacing the tube or other components.

I don't think it would be uncommon for a tube to "sputter" a second or two on the first cut of the day. Why not just do a work-around for now? Rather than have it start cutting on the part, why not just draw a straight line off to the side of the material (or off the workpiece completely if necessary) just to get the laser firing? It would only mean a few seconds of lost time and it would prevent the tedious "rework" or re-cutting the first bad part. I know this does not fix anything, but it might be a more tolerable and systematic startup procedure for the time being. If you start losing the beam well into the run, then it is a different situation.

[Chad Fitzgerald]

there is no ryme or reason to WHEN it does it.
I just happened a couple minutes ago, it was on the start of the third run of the same file. First second or so of the run.

[Chad Fitzgerald]

OK, done it again, after the last one, next run(same file) went fine. Next go, did it again, i happened to be watching the red laser indicator and the laser was not firing.
before i go tearing into complicated expensive parts, i will check the safety switches on the door, anything else i should check before the tube
chad

[Bill George]

OK, done it again, after the last one, next run(same file) went fine. Next go, did it again, i happened to be watching the red laser indicator and the laser was not firing.
before i go tearing into complicated expensive parts, i will check the safety switches on the door, anything else i should check before the tube
chad

I think your Laser Pro is also Chinese or Taiwan made but no power meter or ma milli amp meter? Yes check the door switch, water flow switches and connections on the control and power supply to make sure the screws holding the wires are snug. Keep it Simple.

My best guess is the red LED showing tube firing is showing a On trigger signal to the tube HV power supply. Doubt in that case it is the tube, but wiring or safety switch issues.

[Bert Kemp]

I would also check the wires on the laser head. You say it only happens right at the start. Thats when the laser head jumps to start its cut, maybe a loose wire that disconnects then settles back in place as the laser head is moving and not jerking around like when it first starts.

[Richard Rumancik]

Well, if it happens throughout the day maybe my work-around isn't satisfactory . . . is it always within a few seconds of the start of the file? If so it seems like the tube is cooling off during the idle period.

The only other thing I can suggest is to investigate is the possibility of adjusting the tickle setting on your machine. Do you have a Synrad tube? It should be adjustable on the control panel with Synrad but I am not sure about Deos tubes. This setting is supposed to pre-energize the laser tube so it is on the verge of firing so that when it gets the first command to fire, it starts without hesitation.

The behaviour you describe is a bit odd though, as it misses AFTER the initial fire. But it might be worth an experiment. You should just change it one step at a time, as if you set too much tickle it may fire when it should not. (Too much could result in "shadows" during rastering. Not sure if it would negatively affect vector cutting as much.)

[Richard Rumancik]

OK, done it again, after the last one, next run(same file) went fine. Next go, did it again, i happened to be watching the red laser indicator and the laser was not firing . . .

I understand that the "red laser indicator" is supposed to report if the laser is firing or not. I don't know how it is tied into the laser tube circuit, but if it shows "no laser operation" AND it is not cutting at the time, this does not look good. I don't think tickle will solve this. It seems like the tube is indeed cutting out for a second.

Is your machine a Spirit GX or what model is it? What tube does it have? If it is a Synrad you might want to check the Synrad manual. The tech people are often helpful even though they do not sell direct to the user.

There are some diagnostic LEDs on the mainboard. Maybe you could find their meaning and try to monitor. You would probably need a video camera to catch the event.

Bill, the GCC machines are made in Taiwan but they have no similarity to the Chinese lasers as far as the laser source.

[Chad Fitzgerald]

OK
Laser pro is taiwan, no meter and no water flow. will check the wires.
the red LED light does not light up when this happens.

Wires on laser head??? Do you mean the lens carriage?? there are no wires there except for the auto focus. Do you mean somewhere else?

It is a synrad tube, i believe, tickle settings, i will have to read up on that before i change anything.
Today it did it at the very start of the run, so it missed the initial fire.

I just finished 42 seperate runs this morning. It happened only 2 times out of the 42. Dont know if that helps.
Thanks all
Chad

[Chad Fitzgerald]

Spirit, about 4 years old, very few hours on it relative to the supposed life of a tube. only a guess but somewhere between 500 and 1000 hours at most.
the LED shows no operation when the laser is not working (when it should be)

I will call GCC and see what they say

Thanks Chad

[Bert Kemp]

Sorry meant wires at the end of laser tube not head.

OK
Laser pro is taiwan, no meter and no water flow. will check the wires.
the red LED light does not light up when this happens.

Wires on laser head??? Do you mean the lens carriage?? there are no wires there except for the auto focus. Do you mean somewhere else?

It is a synrad tube, i believe, tickle settings, i will have to read up on that before i change anything.
Today it did it at the very start of the run, so it missed the initial fire.

I just finished 42 seperate runs this morning. It happened only 2 times out of the 42. Dont know if that helps.
Thanks all
Chad

[Neil Pabia]

Im not familiar with the Chinese/Taiwan lasers but is it possible that the encoder strip is dirty and it just catches every now and then?

[Richard Rumancik]

I know everyone is trying to help Chad but he does say what kind of laser he has in his signature. No glass tube, no wires coming out the end. The GCCs all use encoder wheels in the servo motor I believe so no encoder strips. (You can clean an encoder wheel if you are careful but I have some doubts it is a factor.)

It seems to be a problem with initial firing from what Chad has stated so far. Two glitches in 42 are a nuisance but not a show-stopper yet.

Chad, I saw that it was a Spirit but I see different flavors of Spirit so that is why I asked about submodel. Is it a GX?

I saw that the GX has an 8-second warm-up period after closing the door. What is this all about? And are you waiting the full 8 seconds before starting the laser? Or does it just wait till 8 seconds have passed on its own, if you press start right away? On my Mercury there is no waiting time so this was new to me.

Don't know if that has anything at all to do with it, but it seems like there is some kind of "delayed starting" phenomenon going on. I'm still waffling about tickle as to whether it could help. Do a search on this forum and you will see some posts on that topic.

I think Rodne Gold is pretty familiar with the Spirits - perhaps send him a PM and direct him to this thread.