Problem with laser power

[bobkeyes]

Marco,

Same ground wire I've always had. Again, if it was bad wouldn't the mA's drop down?? Or at least be erratic.

The farther away you get it gets a little worse. I've tried all four corners and the middle. Not much difference.

As stated before, when it first starts it's cut at 1mm, it cuts through the 1/8" plastic for about 1/16" to 1/8" then it just barely marks it.

Not sure about the no problem with tube. I can't seem to verify that in my mind.

Look at this pic. This was done 12" away from mirror #2 with NO air assist nozzle. That's half the distance of my bed. Hope you can see that the cut starts much deeper than it finishes.

The close up shows just the first part of the cut. The black in the cut is where it cut through.

[bobkeyes]

waltfl,

I like your chiller. I took an old dehumidifier. Placed the coils on it down in the water. A controller sensing a type K thermocouple turns the dehumidifier unit on and off. Seems to work well.

[waltfl]

Hi bob
do you use air assist?? what kind? what kind of lens you use?
did you check all four corner of your work area?
52mm focal length is to high it should be 50.8mm from top of lense to surface of material just 1/10 of a mm its enough to loos power up to 30%
did you check the laser head if it is plump to the surface on all the area?
greetings
waltfl

waltfl,

I understand, but I have a chiller running at 66 F. After long cutting, 3 hrs. continuous, session the temp only rose about 2 degrees F. Checked exit water temp yesterday with fluid filled thermometers. Exit temp of water is about 68-69 Degrees F. Tube is filled with water and it has GOOD flow.

[Tech_Marco]

The tube fired on 10~15min without a problem, that let me to believe that the tube is good. It won't cut only when the tube installed in the machine, correct? If it is bad, it won't let you burn after 1~2 min.

How about remove the laser tip out find fire the laser without the focus lens in placed. Let's see if anything to do with the focus lens. If not, i really got no clue what caused this problem.


Marco

[waltfl]

Hi bob
another idea
check your bed if it is plan and level sometimes if the bed is twisted or bend just a bit it could bring this results too
greetings
waltfl

Hi bob
do you use air assist?? what kind? what kind of lens you use?
did you check all four corner of your work area?
52mm focal length is to high it should be 50.8mm from top of lense to surface of material just 1/10 of a mm its enough to loos power up to 30%
did you check the laser head if it is plump to the surface on all the area?
greetings
waltfl

waltfl,

I understand, but I have a chiller running at 66 F. After long cutting, 3 hrs. continuous, session the temp only rose about 2 degrees F. Checked exit water temp yesterday with fluid filled thermometers. Exit temp of water is about 68-69 Degrees F. Tube is filled with water and it has GOOD flow.

[bobkeyes]

waltf,

All that checks OK. As previously posted, I had 3 disks to cut. The first cut fine. The second cut about 1/2 of the circle fine then not much on the other 1/2. The 3rd just marked the material. These were all run from the same drawing. No time in between cuts except to move head to new location.

[Tech_Marco]

Bob. go check out a new tube and return the old for me for testing. If it is bad, then I credit back to your account.
It's very hard to do trouble shooting in this case. We need to install the tube in our machine for testing


Marco

[bobkeyes]

Marco,

Here is pic of the pattern without focus lens. You can see that there is a scorched part where it starts, then nothing. It seem to be losing more power as we go. I now have to hold the "laser" button much longer to get it to scorch a piece of tape to check alignment.

Don't know if you will do this or not, but I've got to get running. Would you send me a new tube, a new power supply, and a new HV cable. It's got to be one or the other. I'll run a new ground wire. I'll install the tube first. If that fixes it then we've solved the problem. I'll return the old tube. You inspect. If I've damaged it in someway, I'll pay for it. If it doesn't solve the problem then I'll install the PSU. If that fixes it then I'll pay for the power supply and put my old tube back in. In any event I'll pay for the cable.

I won't solder the connections to the new tube. I'll use wire nut springs on them. I also will not put silicone on them until I know it's the tube.

How's that sound. I'll even give you my CC # to hold until we find out what I owe you for. If this is not acceptable then tell me what you will do.

Thanks a lot for your and waltf's time and expertise.

Sincerely,
Bob Keyes

[Tech_Marco]

Bob, I can't do it. Either you return everything for us for testing and we ship you a replacement for any defective item. Or if time is critical, you check out and pay for new items and do the test in your location. Then return the defective and no-longer needed item for us and we will credit back to your account.

FYI, it happened twice before that a return item tubes were not-defective after we test it and we no longer can sell it as it is used. It cost us a few hundreds for the not sell-able tubes here. It is a big waste

If you order it today before 3:00pm, most likely that we can ship it out today

Thank you for your understanding.

Marco

[bobkeyes]

I do understand, but then again I don't. But, that is beside the point.

Does your PSU come with a plug for the HV?
Bob Keyes

[bobkeyes]

Also, can I use a 60 watt PSU on this 45 watt tube. I plan to change to a 60w tube in the future.

[Tech_Marco]

No plug but solely a bare long cable with silicon tubing wrap up to protect the wire from wore out or from "leaking"

Marco

[Tech_Marco]

Also, can I use a 60 watt PSU on this 45 watt tube. I plan to change to a 60w tube in the future.

Yes. But you need to limit the current not go ove 18mA for a 40~45W laser tube. A 60W tube need around 22mA. Most 60W can go as high as 24~25mA. if you're planing to use a 60W tube, then buy a 60W power supply


Marco

[bobkeyes]

Thanks. I'm trying to decide if I just need to bite the bullet and go for 60 watt now. It would sure speed up the work.

[bobkeyes]

It says you don't have the 45 watt tube????