Help me choose a cheap laser engraver

So one of my future projects involves acid etching machine tags.  I have already experimented with cut vinyl masks, toner transfer masks and painted. Paint wins.

So a while back I saw a video with a gent doing exactly what I need to do and one of his methods was to spray paint the brass and use a laser engraver to burn it off. Desktop engravers are getting cheap.

Question is, What kind of power would I need to burn paint off metal? Would an astonishingly low priced 3000mw unit do the job? Do I need more? How much more?

Help me make cool things GRM!

The cheapest laser engraver you can find should cut through paint.  If that's all you're looking for I wouldn't worry about much more than finding something that does the size you want and is reliable. 

If you're looking for cheap, I think I remember a build on reddit that was a CNC engraver that used a dremel as the cutting motor/head.  I want to say they 3D printed most of it and the actual parts cost $275?  I'll go digging.

A couple of your examples look stamped, or possibly even cast.  What look are you going for?

I will be acid etching. Much like this video

This is a similar look to what I am going for. I just have not had luck with toner transfer and a new laser printer that will do it better is more expensive than a laser engraver

If you're just looking to do tags a 3018 CNC could be setup to do the engraving. SainSmart sells a 5.5W 450nm blue laser attachment for it as well that'll burn wood, I'd assume that would go through paint, but it won't mark metal.

You can get a kit from them for $450 or so. Just swap the head if you have preprinted data plates to engrave.

Edit: GlowForge is the hyped model on the maker YouTube channels and it'll supposedly engrave a number of metals. They're still $2500 though to start.

In any case, please take care of your faceballs and use high quality eye protection in the correct wavelength for the laser you're using. Don't trust eBay laser safety glasses, shop an actual scientific/industrial supplier. It only takes a small mistake when working with high power lasers to permanently blind, and cheap laser engravers don't have the safety shielding and interlocks that expensive laser cutter might.

Go looking for "K40" engravers on Alibaba/eBay/whatever. Then look at some of the DIY writeups on trying to use them, including references to accidentally burning holes in the wall. It's quite entertaining.

A friend has a GlowForge. It's the easy button option. Not the cheap option. But he's done a bunch of stuff for me and if you prefer to use your tools instead of working on your tools, that's the one.

newrider3 said:

In any case, please take care of your faceballs and use high quality eye protection in the correct wavelength for the laser you're using. Don't trust eBay laser safety glasses, shop an actual scientific/industrial supplier. It only takes a small mistake when working with high power lasers to permanently blind, and cheap laser engravers don't have the safety shielding and interlocks that expensive laser cutter might.

If it's a CO2 laser, ordinary polycarbonate safety goggles are fine. They're what I used when I used to work for Amada Laser, and I did get hit with a few diffuse reflections from a 2 kw laser while wearing them. They wouldn't have blocked a direct hit from the beam, but neither would 24 gauge sheet steel. Even Harbor Frieght specials are fine - the CO2 laser wavelength is absorbed by polycarbonate itself.

Visible light or YAG lasers are another story - those will need specialty laser goggles, from a reliable source.

It doesn't take a very high powered laser to remove paint from metal. Actually etching into the metal is a different story, particularly brass.

This is the machine I have been looking at. 

Under $200, 6"X6" area, small, lightweight and portable. Reviews seem positive with the caveat that it won't cut through 1/8" plywood without 5 or 6 passes. I have no interest in that. Most folks only seem to be interested in burning pictures of star wars characters on wood or cardboard which tells me nothing.

I have just this one specific use in mind. Cutting the mask for acid etching. 

I might just pop on this thing and see.

The actual laser power is listed as 4000 mw. That's going to have no trouble removing paint or masks from an etching tag.

The wavelength specs indicate it's bluish-purple. You will want to put the machine in a proper enclosure before using it, especially with metal, which could send out some pretty dangerous reflections.

If you want, I can put you in touch with a friend who has gone down this rabbit hole to some extent. Drop me an email.

He made me these boss business cards for SEMA :)

Jumper K Balls (Trent) said:

This is the machine I have been looking at. 

Under $200, 6"X6" area, small, lightweight and portable. Reviews seem positive with the caveat that it won't cut through 1/8" plywood without 5 or 6 passes. I have no interest in that. Most folks only seem to be interested in burning pictures of star wars characters on wood or cardboard which tells me nothing.

I have just this one specific use in mind. Cutting the mask for acid etching. 

I might just pop on this thing and see.

 

 

I go to that site and it says "FLASH SALE!" across the top. Which, umm, I'm not sure if I find funny or a little terrifying.

MadScientistMatt said:

The actual laser power is listed as 4000 mw. That's going to have no trouble removing paint or masks from an etching tag.

The wavelength specs indicate it's bluish-purple. You will want to put the machine in a proper enclosure before using it, especially with metal, which could send out some pretty dangerous reflections.

What would that enclosure be? A polycarb box of a certain color? Or something opaque?

...because I might have maybe clikced on a few things...

Keith Tanner said:

MadScientistMatt said:

The actual laser power is listed as 4000 mw. That's going to have no trouble removing paint or masks from an etching tag.

The wavelength specs indicate it's bluish-purple. You will want to put the machine in a proper enclosure before using it, especially with metal, which could send out some pretty dangerous reflections.

What would that enclosure be? A polycarb box of a certain color? Or something opaque?

...because I might have maybe clikced on a few things...

It could use either a color that blocks the wavelength of that laser (just like the safety goggles - you can get this from industrial safety shops) or opaque. I'd set one up with a 450-nm blocking window so you can keep an eye on the process; I wouldn't want a completely opaque enclosure.

Thanks. I'll look into it. 445 nm wavelength, I'll see how big the box needs to be and order up some window material (like this?). A box would also allow for some ventilation.

And no thanks to you, Jumper. I've been interested in these for a while and, well, this put me over the edge.

In reply to Keith Tanner :

Keep us updated. I have no immediate need, but I do have a want.

I'm not sure what kind it is, but our local makerspace has a pretty heft looking laser engraver. It uses a red laser, and they have a clear polycarb window on it, with no warnings about glasses or anything. It cuts and burns wood, but is also covered in warnings about putting metal inside despite the working area being expanded steel mesh. 

This is what it does. I know your looking at getting paint off metal, which is entirely different, but I thought it would help to see an example. It's more legible in person, but I'm not great with a camera.

It's a pretty massive steel contraption, 4 foot wide, maybe 2 deep and 3.5 tall. They are using a cheap 4 inch grow tent exhuast fan hooked up to PVC to get rid of the fumes and control smoke. 

I haven't played with it yet, but I do have some cutout tokens that it made if I can find I'll upload a picture of. 

Nothing else to add, other than there may be a similar thread I started in 2017 floating around, I'll try to dig it up, that may have some more or different information to cross check, or could be completely outdated by now.  this thread

Keith Tanner said:

If you want, I can put you in touch with a friend who has gone down this rabbit hole to some extent. Drop me an email.

He made me these boss business cards for SEMA :)

Card looks great , I assume he bought the blank colored cards and laser etched your info.....

or did he just get a big sheet and cut the blanks ?

He buys pre-anodized blanks. His own cards are blue and have a great line drawing of his own car on it. The graphic on mine is the R&T cutaway of our ND V8 :)

It's here! It's here! Woooo!

Should I start a build thread or continue here?

Well I still haven't bought one so I want to read about it any where you decide to post it

Oh, +1.  I almost pulled the trigger on a couple different ones on Amazon, but didn't have any information that I trusted.  I'm very interested in your impressions.

Build thread it is. I am learning this thing, so ask as many questions as you can so I can learn things by finding the answers.

https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/fun-with-a-laser-engraver/166130/page1/

Hey guys, 

I remember seeing this thread a while back, and really liking it even though I didn't really understand all of it. 

Just recently I removed the janky old stereo out of my 74 REPU. I was chatting with a friend about what I should do about the hole in the dash. I even started a thread on here regarding this. My friend said he could cut me a blanking plate for the dash. I was thinking about this thread and thought that maybe I could do something like this to the blanking plate. If I was to do this what type of metal is best for doing this? Could I use brass or copper? 

It takes a serious laser to cut metal. Not hobby grade. More likely you'd cut a plate out of plastic instead.