Laser Tube Not Firing.

[Imperial Armories]

Hey guys.

i have a new problem with my shop machine. The machine its self is a couple years old, but has had most of its components replaced at various times making the original model number almost useless.

I have an 80w power supply that is about ten months old,
http://www.ebay.com/itm/80W-Laser-Power ... 25913946f5 <--- this one.

and an 80w laser tube that is about seven months old. (just past the warranty, go figure)
http://www.lightobject.com/High-Quality ... -P118.aspx <---- this one.

The issue im having is that when i press start, or the test button on the power supply, the wire that leads to the back end of the laser tube starts sparking.

I replaced the wire...made sure the connections were all solid, and wrapped everything in electrical tape, replaced the cap shield thing and the sparking stopped, but the laser its self won't fire.
I have tried removing the safety switches and testing it, i checked all the electrical connections i can find, and i have checked fuses and whatnot. No joy.

Not sure if its relevant or not, but in the past two months, the lasers cutting power has been getting lower and lower irregardless of what setting i use on the machine.



So, any advice? or is my laser tube just dying.

thanks

Jeremiah

[waltfl]

hi there if the tube power did go down then it is a sure sign that the tube is gone and you need a new tube.
greetings
waltfl

Hey guys.

i have a new problem with my shop machine. The machine its self is a couple years old, but has had most of its components replaced at various times making the original model number almost useless.

I have an 80w power supply that is about ten months old,
http://www.ebay.com/itm/80W-Laser-Power ... 25913946f5 <--- this one.

and an 80w laser tube that is about seven months old. (just past the warranty, go figure)
http://www.lightobject.com/High-Quality ... -P118.aspx <---- this one.

The issue im having is that when i press start, or the test button on the power supply, the wire that leads to the back end of the laser tube starts sparking.

I replaced the wire...made sure the connections were all solid, and wrapped everything in electrical tape, replaced the cap shield thing and the sparking stopped, but the laser its self won't fire.
I have tried removing the safety switches and testing it, i checked all the electrical connections i can find, and i have checked fuses and whatnot. No joy.

Not sure if its relevant or not, but in the past two months, the lasers cutting power has been getting lower and lower irregardless of what setting i use on the machine.



So, any advice? or is my laser tube just dying.

thanks

Jeremiah

[Imperial Armories]

Ehh i was afraid of that.

Is it normal for a laser tube to last seven months? I mean we picked this thing up in January, and it has had light use. Maybe a couple hours a week. Nowhere near the ten thousand hours advertised.

What would cause it to die so quickly?




Also, would the laser tube finally kicking the bucket cause the wire to start sparking? Cause prior to this, i had no issues with it.


thanks


Edit: Also i did a pretty thorough inspection of the tube...no cracks, no water where it shouldn't be, etc. The last tube that died on us died in spectacular fashion. Broken glass, etc. Do these things die and just show no signs of having done so aside from just not working anymore?

[Tech_Marco]

If you're not over driven it (over current), it is not very common that a Reci tube die in 7months. Take a look on the negative terminal (the gold ring) and if you see that there is some oxidation in purple color, it means that the tube was over current.
Did you set a max current limit on your system? If not, then a 80W CO2 laser power could kill a 80W tube very quick as a 80W power supply can output as high as 34~36mA!


Marco
(in China)

[Imperial Armories]

We usually only cut at 80% power, but im not sure if thats what your talking about or not.

where would i go to set a max limit?

Also im not seeing any purple discoloration, but im not terribly certain what im looking at. Do you have a picture of a tube that this has happened to?

[Tech_Marco]

Each laser controller should let you do max current setup. "%" doesn't mean anything. 80% could be 20mA or 26mA, 30mA , or 35mA...and so on. The most important thing need to do is to configure the max current output allow from your power supply. Each power output differently even though the same brand or the same model.

Sorry I don't have a picture to share. Just remember that the two piece of ring inside a laser tube is either gold color or silver. If it got over-driven, it will leave some purple burn mark.

By the way, you need to double check your power supply to see if it is working properly after the arc firing. If the arc firing was big and last long, it could damage the power supply. Also, you need to check the focus lens because it got dirty easily from the smoke and it could drop cutting power a lot!


Marco

[waltfl]

hi I just wana give a couple more reason one is the cooling water temperature if it exceeds the max of 25C ( 78F) with every degree you loos about 15% power and above 30 will destroy the tube
air bubble inside the tube gives the same result.
without a picture I can not say what could have created the sparking, it could be a loos connection, or the tube wire somewhere could get damaged and spark against the housing
it is very important to watch the temperature with a thermometer there where the cooling water enters the tube and the current with a meter. a check with the finger for temperature will not do it and there is now ay to say how much current goes in the tube.
gretings
waltfl

Each laser controller should let you do max current setup. "%" doesn't mean anything. 80% could be 20mA or 26mA, 30mA , or 35mA...and so on. The most important thing need to do is to configure the max current output allow from your power supply. Each power output differently even though the same brand or the same model.

Sorry I don't have a picture to share. Just remember that the two piece of ring inside a laser tube is either gold color or silver. If it got over-driven, it will leave some purple burn mark.

By the way, you need to double check your power supply to see if it is working properly after the arc firing. If the arc firing was big and last long, it could damage the power supply. Also, you need to check the focus lens because it got dirty easily from the smoke and it could drop cutting power a lot!


Marco