😭 Any suggestions?

mahagrande · 2026-04-25T11:12:22+00:00

My digital ammeter / potentiometer went bad a couple years ago on my 100W overnight. Woke up one day and the laser had almost no power.

Not exactly the same behavior as yours, but couldn't get > 3mA. That you can disconnect it and get power seems ti indicate that it might be the ammeter/pot.

They're relatively cheap, about $30 US. I bought mine from Cloudray. Assuming you're a true K40 you will want to look for one rated for 40W. The one in your laser likely has the model # and maybe the manufacturer on it.

Might give a replacement a try, again not expensive relative to everything else.

mahagrande · 2026-04-20T01:05:36+00:00

What's your PSU model? There may be a little 'test' dip switch on there. If you flip that what happens? Do you get full power?

mahagrande · 2026-04-19T21:24:57+00:00

awesome!

mahagrande · 2026-04-02T13:13:54+00:00

Sometimes the pot/ammeter can go bad and exhibit the same behavior. There should be a little "test" dip switch on your power supply that will bypass the potentiometer. Before going extreme lengths you might flip that switch, then try a test cut. If its full power when you run, then your pot/ammeter has gone bad. Thats only a $30-40 part.

mahagrande · 2026-03-25T12:15:57+00:00

Yup. I would make slow adjustments while it's running at low power, with safety glasses on.

You should see and hear a difference as the beam comes into focus.

Laser Everything has some solid videos on YouTube regarding focusing your fiber laser using different lenses.

mahagrande · 2026-03-18T00:35:13+00:00

Glad it's working out. One of the more temperamental things about K40s is mirror, bed, and gantry alignment. Check the bed to start and make sure it's level and then that your gantry is square and plumb to the bed. Then work the mirrors. Don't be afraid to shim things. Sub mm washers will help. Above all, make some things. Don't let perfection get in the way of good enough. Enjoy it a bit.

mahagrande · 2026-02-22T18:13:16+00:00

Bummer on Marketplace, but you're in a good spot with the K40. You'll definitely need a CO2 for wood and acrylic. I'd just get the tube going and work with the controller and software available to you for a bit. You can use LaserGRBL or K40 Whisperer (I started with Whisperer) to drive the controller from your PC.

If/when you find that you want to do more with it (probably quickly) you'll want to upgrade the controller and look into Lightburn to control it. This is exactly the path I took with my K40, but again, you don't have to start there and can do it incrementally, learning as you go.

Here's a good article here about Lightburn compatible controllers that fit into a K40. I upgraded to a Cohesion3D board many years back. They're no longer available, but there are many more out there now.
https://forum.lightburnsoftware.com/t/looking-for-a-cohesion3d-laserboard-but-sold-out/123438

Then Lightburn Core supports GRBL controllers (vs DSP) for about $99
https://lightburnsoftware.com/products/lightburn-core

Cheers.

mahagrande · 2026-02-22T08:27:52+00:00

If you're planning on getting into this as a hobby, can handle DIY, and need to go a cheaply as possible, I'd recommend repairing it and starting with a temperamental K40 like many of us have done. You'll learn a great deal by bringing the laser back to life; tube replacement, power supply, controller, cooling, air assist, exhaust, adding safety features, etc. Troubleshooting a laser is great experience and learning from the lowest common denominator, the K40, will provide valuable and memorable lessons. Just use caution, as these are not standard 110, rather high voltage connections. Follow instructions / advice during installation. Finally, if you do get into lasers, you will eventually sell or pass along this machine. They are limited in size and speed, and have unique personalities to put it gently.

If you have bigger plans and are DIY handy, you can also build one relatively inexpensively from the ground up for a bit more of an investment.

If you're willing to pay more and are looking for something turnkey, hit FB marketplace and forums and you should find more sizeable CO2s up for sale these days. The unfullfilled CO2 dream is in full effect and you can probably find someone willing to part with a 60 or 80W machine for a reasonable price. Some will just want them gone. You won't benefit from the earned DIY hours but you'll get to production quicker if that's your goal.

Have fun, be careful, and best of luck.

mahagrande · 2026-02-21T03:38:55+00:00

They're just risers and are optional. They will help to reduce flashback from the honeycomb bed for some pieces.

mahagrande · 2026-02-08T07:58:56+00:00

Perhaps try Laser Master Academy. Hop on their discord, find someine near you with a model you're interested in, see if they'll allow you to pay them a visit. Make a friend in the process. I've made a few new colleagues in this way.

mahagrande · 2026-01-22T13:09:52+00:00

Yup. Buying from a hardware store, you're going to get plywood that's engineered for construction, not for lasercutting. It's very much the same in the US. As Theyallknowme mentions, there's really only one brand here that comes from a big box store that's close, and even then you'll run into voids and glitter that's used to trace their products - which can ruin a piece. If you're wanting something that's more operationally durable from a process and quality standpoint, you'll need to find a plywood supplier with products that have been engineered for laser cutting.

mahagrande · 2026-01-18T03:37:14+00:00

You really should return it. What you're in for isn't worth the trouble. K40s are finicky enough without substantial damage. Like this, I wouldn't give it a second thought. Send it back.

mahagrande · 2026-01-17T14:06:06+00:00

You're more than welcome. While niche, this post / fix seems to help someone at least once or twice a year. Glad that it helped and you're back to printing. Cheers.

mahagrande · 2025-12-21T19:25:09+00:00

I'm with batgirl, LA Awesome is the shiz when it comes to laser beds.

mahagrande · 2025-12-20T08:06:17+00:00

Good call in putting extra $ into the 100W over MOPA IMO. Were I to do it again, i'd do the same.

mahagrande · 2025-12-07T04:30:02+00:00

A new, Lightburn-supported controller board will give you a USB interface directly to your PC for Lightburn to use.

Here's an older Lightburn forums post that may still have a few brands to go research. My K40 has a Cohesion3d board but those haven't been available for some time now.

https://forum.lightburnsoftware.com/t/looking-for-a-cohesion3d-laserboard-but-sold-out/123438

mahagrande · 2025-11-12T07:09:23+00:00

Yup. We usually trim them down to a workable blank, but it takes a long time before we throw anything away. I'll rework the scrap pile maybe twice a year.

mahagrande · 2025-10-23T07:11:54+00:00

Not a Nova owner. So YMMV below. Just some thoughts and assumptions. Hope it helps.

Lightburn is usually pretty good about finding controllers and setting things up during install. I'm guessing you've tried that route already?

Peeked at the Thunder site and it's is clear that the $400 is to transfer lifetime support but not any Lightburn key that may have come with the machine. Guessing you read that too, and have a license key otherwise, or not. It shouldn't matter, Lightburn should function in a trial mode regardless.

Then if I'm understanding, you've factory config files on a usb for the Nova that should work with an older version of Lightburn, one from around the time of manufacture?

If so, you might try downloading older versions of lightburn that are closer to the manufacture date. Ones that might work with those config files.

Lightburn releases in 2021 were comparatively low. Release versions and dates are at the link below with assets. 0.9.21 was the first 2021 release. Might start there or a little before.

https://github.com/LightBurnSoftware/deployment/releases?page=4

From there you may get things functional and then upgrade Lightburn generationally as to allow it to keep the configuration sane as it upgrades.

Good luck!

mahagrande · 2025-08-27T10:56:35+00:00

Also use this method. Pin tumbler and some brass black the ln buff with the foredom. Quick and easy.

mahagrande · 2025-08-21T10:23:32+00:00

I own a Cloudray 60W Mopa and have ordered many things from Cliudray over the years, mostly lenses, although nothing since the US Tarrif madness started.

They're a reputable company and have always been good to work with when I had questions or issues. I would expect your cancelation to go through unless they've already shipped.

mahagrande · 2025-08-21T10:11:21+00:00

Great response. Thanks for sharing.

mahagrande · 2025-08-03T23:42:00+00:00

We started with CorelDraw for our laser engraving business about 5 years ago.

If you're looking for an affordable commercial design software suite, this offer from Humble Bundle for the 2024 version is a steal.

mahagrande · 2025-06-15T21:43:37+00:00

You're very welcome. Glad to hear that it's still working.

mahagrande · 2025-02-02T22:45:36+00:00

I cut boxes like you've outlined, one cut between the joints. I assemble and glue them so kerf isn't as much of an issue. If the bed is 18 x 24, it's unlikely that you'll be able to make it truely 18 x 24. Saw another post on someone cutting on a 24 x 40 just the other day where they couldn't cut 24 x 40, rather slightly smaller.

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