Laser beam dances on the outer coupling

Community Laser Talk
1

I have a 80 watts Orion Tech (Chinese) laser machine. It was bought on Amazon. It has worked fine, but last night I saw the laser beam doing some tumbling dance near the output coupling. Here is the video:

Video on Imgur

So far, all the wiring connections seem to be well made. My chiller is filled with distilled water.
When I took the video, the machine was cutting at 19 mAmps, so I don’t think it would be a low power problem.

I’ve been getting jagged cuts lately. Not too bad, but you can certainly feel cuts are not smooth when you slide our finger on the cut edge.

Any advice or thought on the posible cause?

2

Normal behavior for a gas discharge tube running at relatively low power levels. Don’t worry about it, it’s harmless.

3

Thanks for your prompt answer.

I want to add that I was running it at 19 mA -according to my ammeter- while I took the video. According to the Engrish label attached on my machine, the max rated power for my tube is 20mA, so it should be far from being low power.

I just flushed my entire coling system and refilled with frsh distilled water, just in case. I didn’t observe any change.

4

That’s interesting. I have an 80 watt Orion Tech, and mine has an EFR F2 tube which is rated for 28mA.

Beam wander usually happens mostly when the running current is less than the cathodes maximum capacity. It’s often affected by temperature. (worse when cold)
I can’t remember the physics behind it, but 25 years ago when I had a small neon sign shop and was fascinated by gas discharge lighting in general I probably could have told you. I could probably find the answer in the big stack of books I have about neon and discharge lighting if I was motivated enough.

But it doesn’t hurt anything and it wont affect the performance of the beam exiting the business end of your laser. No worries.

5

I just checked and I also have a F2 tube, which is rated at 28 mAmps, in their website.
Looks like I probably have a wrong label attached to the machine.

Now I feel confident to try using it at 24 mA and see what happens.
Will post my findings tomorrow.

6

Yeah, 24mA is what I use as a nice conservative maximum. That works out to be 65% power on my particular tube. Yours will likely be similar.

I assume your machine has a Ruida controller and not Top Wisdom?

7

Exactly, Ruida controller, 20x28 inches. Manual bed. I’m considering some kind of electric motor to raise and lower the bed.

8

You’ve got the same beast as me. I’d like to motorize the z axis on mine also but first I need to fix the damned thing. The jack screw in the corner with the knob is a little bent, so when raised/lowered the table wobbles around a little 2mm diameter circle. On my list of things to fix. So irritating…