[InspWoodcrafts]

Hello community, thank you for being a resource - any help is greatly appreciated.

My Chinese laser arrived in February and after leaning the machine it was working wonderfully, until the power supply went out. It's still under warranty, so after a lot of hassle, the company I purchased it from sent a replacement power supply. Yesterday, I replaced the power supply and everything seemed to be in order ... at least for cutting.

Engraving is a separate issue. With the original power supply, engraving was clean and crisp but now it is blurry. (See attached photos)

I've checked the alignment, we seem to be good there. I've inspected and cleaned the mirrors and lens - no apparent issue here.

I saw another thread that suggested reloading the design file into the unit - I only noticed a minor improvement deploying this technique.

My theories at this point are as follows:

• The company may have sent me a wrong power supply unit - box is labeled 40w and I have a 50w machine.
• I could be experiencing power loss - have not yet tested since I need to get a proper tester/meter.
• The tube could be bad ... its original with less than 30 hours on it though.
• Or I just have bad luck and this machine was a terrible idea.

Any help and suggestions would be appreciated. Many thanks!



ScheduleSchedule

[fixtureman1]

can you engrave on the same piece that you used for the original different woods would engrave differently

[InspWoodcrafts]

Both pieces are poplar from the same original board. Both pieces have been experienced the same conditions - but one was finished before the power supply went out and the other was finished after the power supply was replaced. I've done a few other tests from scraps from this board, the issue should not be the wood. It is likely something to do with the machine/controller/etc.

[inversealien]

Wow. same exact situation here. chinese cutter... power supply went bad, company replaced it, 10w difference... (mine is now a 60w with a 50w PSU) after replacing cutting seems to be unaffected but etching is blurry and weak. Im going to try to sucker my EE cousin to help me with it this weekend. If we ("we" meaning "him", hehe) figure anything out, I will let ya know. Till then I am certainly going to keep my eye on this thread.

edit: in case this helps here is what I have tried so far in order (with no results)

ensured the tube was connected well
cleaned mirrors
checked mirror alignment


I still need to try cleaning the lens... tomorrow though.. its bed time.

[fixtureman1]

It almost looks like your out of focus do a ramp test and see if it is still in focus

[TheREV]

The tube is not getting enough power - that power supply is definitely too small.

[InspWoodcrafts]

Thanks. You know that, I now know that but trying to convince them of that has been an ongoing daily challenge. They keep running me through a bunch of tests. Very frustrating. The machine was working great, until it wasn't.

[TheREV]

The best way to check (if you don't have a H/T tester) is to put a multimeter set on mA in series between the black wire (the return wire from the tube) and the power supply. With the power set on 100%, you should get between 22 and 25 mA from a 40W power supply, and between 26 and 28 mA from a 50W power supply. Take a video and send it to the Chinese company. That should convince them.

[InspWoodcrafts]

Well, I'm ruling power supply out as the issue. I've tested it and I'm getting readings of 29.2 mA to 30.7 mA at 100% power. If anything, I may have ended up with a 60 watt power supply unit.

I'm starting to believe this has something to do with the controller unit. I ran a different program yesterday and it just stopped part-way through the job. The file tracked the entire outside dimensions properly, but only engraved the first third of content.

Back to the drawing board... yippee ki-yay!

[TheREV]

It certainly seems to be putting out too much current - for your tube (which may be the issue, and could damage the tube). A 50W tube should not be run at more than 28 mA. There should be a tiny adjustment potentiometer lurking in a hole on the side of the power supply. Run the laser at 50% and adjust with a jeweller's flat screwdriver until you get no more than 13.5 - 14.2 mA on the meter - and then try it again at 100%.

By the way, what were your speed and power settings when doing your wood earlier?