PDA

View Full Version : Newbie Laser Owner Question



William Noyer
11-21-2012, 7:32 PM
I have added my laser engraver to our collection of tools to our business. It is an Epilog Helix 50W. My dad was visiting for Thanksgiving and we were discussing expenses involved with the business and he asked me what the opinion was on whether to leave the laser running vs turning it off. Obviously we are not talking about all night long while it is not being used, but if I am going from one project to another and having a break in between, say 15 minutes to half and hour. We were discussing this because he is an "old" electronics guy (ie; worked with vacuum tubes when he built stereos) and being that the laser is a vacuum tube of sorts was talking about the old thing that it was hard on it to be turned on and off in short increments and that leaving it on was preferable and would allow the tubes to last longer. Any wisdom from the industry out there? Thanks in advance.

Bill

Mark Sipes
11-21-2012, 7:40 PM
I leave my machine on (stand-by) all day long 8-10 hours. Of course it it lasing 6-7 hours of the 10 hours. The time it takes for my machine to go through "ready setup" puts more wear on the system then leaving the machine on. The tube is not affected as far as I can tell by the stand-by state..

And Welcome to the Creek....... Where are you located........helpful to list equipment and software you are using for further help.

Rodne Gold
11-22-2012, 1:06 AM
It's almost always at switch on that we experience laser/tube failures, so we don't switch on and off during the day .. I have no idea whether my tube life is shortened or not...
As to vacuum tubes , well I'm a hifi nut that still uses a lot of valve based equipment , normally NEVER switch it off as it takes about 1/2 an hour or more for my valve stuff to sound good after a cold start..

Rich Harman
11-22-2012, 3:01 AM
I don't believe that turning it off has any effect on the health of the laser tube. Old style vacuum tubes have heaters in them so it makes sense that cycling them on and off will shorten their life. When the laser isn't firing, it (the tube) doesn't have any current flowing through it so it is off anyway.

Dan Hintz
11-22-2012, 7:30 AM
Wow, I could write a mini-book on the subject. Electronics of any type are affected by on-off cycles due to the constant heat-cool cycle that accompanies it. Solder pads are stressed with the mechanical movement of growing/shrinking metal legs on the ICs, capacitors have their electrolytes stressed (though an argument could be made for electrolytes drying out more quickly with constant heat if you left things on), and so on. Overall, it's best to leave electronics on.

From the laser tube side of things, the tube heats up while it's doing work, but cools back down when nothing is being cut/engraved. A constant on/off cycle will stress the seals (minimally, mind you), which leads to premature failures and/or reduced life before repair... eventually the temp of the tube evens out all over, but for a while at least one spot is much warmer than the rest, which means tension, leaks, etc. Best to leave the tube at a constant temp.

Mike Null
11-22-2012, 7:54 AM
+1 On Dan's comment.

Rich Harman
11-22-2012, 4:32 PM
... Best to leave the tube at a constant temp.

How is that accomplished? Glass tubes have nothing that keeps them warm when they are not in use. The only way to keep them at a constant temp is to keep lasing. Do the RF tubes have something that generates enough heat close by to have a meaningful effect on their temperature?

Dan Hintz
11-22-2012, 7:30 PM
How is that accomplished? Glass tubes have nothing that keeps them warm when they are not in use. The only way to keep them at a constant temp is to keep lasing. Do the RF tubes have something that generates enough heat close by to have a meaningful effect on their temperature?

I've discussed this in years past... the idea is to keep the tube from going through extreme temp swings. For example, those people who keep their machines in unheated garages during the winter, then crank it up to 100% 10 minutes after closing the door... the tube goes from 45 degrees to over 100 in a few minutes, not a good idea as it creates imbalances. I always suggest keeping machines in a temp-controlled environment. The same holds true for the glass tubes, though they're more susceptible to outright cracking rather than just leaking at a seal.

Rich Harman
11-22-2012, 10:53 PM
Okay, you quoted me and provided an answer that has nothing to do with the question that I asked. The OP's original question had to do with deciding whether or not to turn off the laser when it wasn't being used. A comparison was made between the laser tube and old style vacuum tubes as a reason to not turn it off.

The general consensus seems to be to leave the machine on unless it will not be used for a long period of time. I agree with that but not for the reason of protecting the laser tube, since as far as the tube is concerned, there is no difference between the entire machine being off and the laser not lasing. Unless, maybe for RF metal tube lasers there is something providing some heat to it while it is not in use.

Do the metal tubed lasers have something that keeps them warm in between periods of operation?

Dan Hintz
11-23-2012, 7:34 AM
Rich,

My comment was more of a sidebar... ideally the tube should be left at a constant temp all over. No, they do not have a heating device, so this is not directly possible, but my comments went back to discussions we've had in years past about tube life, leaving the machine running, etc. In addition to leaving the machine running, it is best to keep the machine as a whole in a temp-controlled environment, which would allow the tube itself to swing in temp as little as possible.

paul mott
11-24-2012, 3:33 AM
Do the metal tubed lasers have something that keeps them warm in between periods of operation?

Rich,

It all depends on the design of your laser machine electronics.

My Synrad RF laser will continue to output the 5kHz ‘tickle pulse’ to the tube for the first 15 minutes or so of standby thereafter removing the pulse but not all machines behave in the same manner.

Paul.