I'm thinking about trying laser engraving, what's the best approach?

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19

OK, OK! Mea culpa! You’re right, I was being snide and insulting when I certainly didn’t need to be, and this is one of the times my filter failed me. I was taking what I read as your arguments and taking them to stupid extremes. Which was poor form on two fronts, first in assuming what you were saying, and second, in using a logical fallacy to basically mock you and your posts. I should know better. I do know better, I should do better. Sorry.

Kids, this is what is known as a teachable moment. Don’t do what I did.

@dart1280 I really am sorry, and I did not think my way through what I was typing before hitting “Reply”. I sincerely hope that we can have reasonable conversations in other threads, and I will certainly be spending more time re-reading my posts before sending, especially my less serious posts, to be sure that any snarkiness is not wholly mean-spirited, and/or is appropriate to the tone of the conversation.

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I appreciate that. Thankyou.

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I didn’t really follow most of it, but actually lots of incomprehensible posts was better than I imagined, which was causing irritation at a question that had been amply answered elsewhere!

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I’ve been waiting for “The Answer” to show up. @dkj4linux has been “Replying” for some time, and he’s probably the SME for lasers around here… :smiley:

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Maybe he is still thinking about Ann Margaret :heart_eyes:

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I’ve been in the MPCNC camp from fairly close to the beginning and used Marlin almost exclusively on numerous machines for years… needle-cutters, laser, pens, etc. All simple, unadorned, CNC stuff for me… no 3d printer functionality needed. I even lent a hand in the development of laser functionality in Marlin… not coding, but running and reporting on tests of different firmware mods, software, boards, etc.

Once I started playing with pens/lasers more than anything else and started looking around at different inexpensive controller boards… I noted that in the “outside world” (the non-MPCNC world) Grbl was the major player for desktop CNC. So I started playing with it more…

When it comes to LASER and basic CNC functionality, I found Grbl ran on very inexpensive Uno/Nano-based controller boards and is very easy to use. And Grbl’s “laser mode” features are especially nice… smooth, uninterrupted, movement of the tool head when engraving and automatic laser power adjustment with feed rate; i.e. no over-burning with acceleration/deceleration of the tool. Check out the “not getting great results” thread to get an idea of the overburn and buffering issues we were dealing with in Marlin at the time. And while Marlin’s advances on the laser front – due to the hard work of many on this very forum – are admirable… Grbl’s “laser mode” had already overcome most of the issues that to my knowledge are still issues in Marlin today.

Another thing – and I’m hardly an expert on this – while similar “laser mode” features may eventually find their way into Marlin, I suspect the underlying way Marlin buffers commands may always be a hindrance. One thing I often do (it’s an old man thing…) is PAUSE/RESUME a job in progress. With Grbl, the action is almost instantaneous… and, with no motion, the laser also turns off. When I’m ready to resume, everything picks right back up where it left off, with no discernible effect on the engraving. With Marlin… interrupting a job has been indeterminant at best… and difficult, if not impossible, to restart.

I realize many first-time machine builders/users need a pretty “canned” and workable solution… and this is where MPCNC shines. For many/most first-timers, Ryan’s design choices and machines – and the support of this community – is second to none. This is definitely the way to go if you are just getting started.

The best advice – having numerous machine builds under my belt – I can give for the rest on us “tinkerers” is… build any machine you want to mechanical completion, including motors. Now take all the bare motor leads in your hand and realize that, at this point, you are completely free to connect and use almost any controller and/or firmware you want to control your machine. So ask yourself what you want to do with it and/or what software chain you might prefer – 3d-print, laser, needle-cutter, milling/routing, etc – and let that guide you in making your choices for what firmware and controller is best for your use case.

My $0.02.

– David

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Thank you David, for taking the time to clearly explain this to me. I’m now sure about what I’m going to do.

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Andy, I think you are like 99% of the users here, and exactly why I built this machine. I wanted to try things like a laser out…and all sorts of other things.

The MPCNC can do everything, the cost of that is it doesn’t do one thing “The Best”. What it is the best at is letting you try everything, and when I say best, I sincerely mean that. I rarely boast about anything. One of those reasons is most of us use extremely similar things and can get you through any hiccups you have.

You have the laser, let us help you get it going. Post specifics on what you have done and where you are stuck.

From there, if you use the laser a lot…buy a specific single use laser machine, change your software, firmware, board, whatever.I can assure you there are still hurdles to cross with each of them. I can tell you know I spent 40+ hours aligning mirrors alone.

Software and firmware are almost besides the point. Anything works, some work better than others. You can actually use and software, firmware, or board you want on the MPCNC.

The real key here is trying a laser a few times. As much as I love them I really dislike using or dealing with them…but I am just one dude. For me they smell, air quality is a serious concern and they leave smoke marks. Until you use the one you have I can highly recommend not buying a single use machine. Heck find a makerspace and watch someone use one.

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Thanks @vicious1, an impassioned stance!
As is often the case, this comes down to me deciding precisely what I want to get out of this, and I’m not absolutely sure. I’m going to buy a cheap standalone laser, and then decide once I understand what it can and can’t do.
Thanks all, you’re an incredible resource.

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Okay well my suggestion there is do not get the cheapest.

The control boards are proprietary and only work with the funky software they send you.
The mirrors are horrible to try and adjust, any time you move the flimsy box they move.
The mirrors tend to actually be too small (the beam is actually very large and only focuses smaller at the nozzle).
No Z adjustment…focus each time?!

I went down this road, and in the end sold it a few weeks later for a loss. I want one but I would only get a mid tier or better. $3-5k for a small work area.

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Sorry one more since this thread got derailed for a bit.

The link you specified is just a vector drawing. The MPCNC is perfect at that with a diode laser ($80-$120). The only time a CO2 laser is better is large raster drawings or cutting.

Just want to point one more thing out. most laser cabinets only let you fit in a work piece the size of their work space, on an MPCNC you can slide in a board as wide or tall as your feet are apart. Think…making a large project and just adding a small brand or word on a board.

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Had to look that up, and yeah, I’d do it. At least twice :grin:

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If your output filter is failing, then so is my input. I just thought you were being…YOU. Not like this is a formal Oxford debate or anything. Either that or my many years in restaurants have just really changed what I consider to be insulting. I chuckled, but then, maybe I’m part of the problem.

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Is this in regards to a K40 type machine? If so, there is an open source software solution out there that is way better and much more stable than the cracked software they usually send you.

Do you really think the mirrors are too small? I think they’re usually 20mm mirrors, and when I align the laser the beam is not that big. 4 or 5mm max, I think.

There are adjustable focus heads for $20 or so, and just need a quick print to mount it on.

If this is not the k40 type lasers then I apologize. I still have my k40 with cohesion 3d board, but I eventually built my 90 watt as the size is truly the biggest limiting factor about the k40 for me.

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Yeah k40, mine was about 2 years back I think?

I had done a ton of research and ended up watch hours and hours of https://www.youtube.com/user/SarbarMultimedia, somewhere in there he showed the beam concentration and I can’t remember all the details but there was like 10-20% loss because the edges get clipped, and wayyyy more if you don’t perfectly center the beam, each mirror looses more and more. Super interesting and I enjoyed learning all of it. Actually I still watch some of his videos, it is like sitting in a class for me.

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I watched this CO2 build series a while back & found it quite informative. Unfortunately, I do not have room to put one of these. https://www.youtube.com/watch?v=t4BfQGhhbOQ&list=PLT2B-jiRa_P4blv69gIPtibwSavtNRHN4
He offers the build guide, parts list & fusion 360 cad model for $5 each & has 2 different build sizes. The Y-1200 has cutting area of 1250 x 620mm & recommends 60-90watt laser ($2600 approximate cost). You can use larger but would have to add extension box. The Y-400 has a cutting area of 600 x 400mm & recommends 35-60watt laser($2000 approximate cost).
https://www.furtherfabrication.com/resources?category=Y1200
https://www.furtherfabrication.com/resources?category=Y400

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I don’t have time to read this entire thread. I’m sure its riviting…

To go back to the original post. I have a 65cm x 50cm version of the first engraver posted with the 3.3kw laser. I bought it on Banggood when it was on sale for $140. It’s served me very very well on everything I’ve needed to burn. If you look at my past posts and threads you’ll see some of what I’ve done with it. I don’t use it to try to cut material, only for engraving. 99% of what I’ve done is wood of some type of another. The most recent thing I cut was a hand-made cutting board.

The stock firmware was atrocious and the software it came with was even worse. I flashed the latest grbl onto the board and I’m controlling it through CNC.js. I use lightburn to make my cut paths. I use Adobe Illustrator and Fusion 360 to create my designs that I export to dxf and then import into lightburn. I’ve done a few projects directly in lightburn using their design editor.

Some of my projects used both the MPCNC and the laser. Those projects I design in Fusion 360. What’s nice about that is I can do a 5% burn path around the perimeter of the design to align the board on the laser before burning the inside stuff.

This isn’t a super exciting piece, but it was one of the more difficult ones to line up square on the machine. Using the outside edge at low wattage passes really helped set this up to burn the words on the board.

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And this is the longest burn I’ve done so far by time. The screwdriver should help give an idea of the size. This one used the entire height of the laser engraver.

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0125201559a2272×4032 611 KB

For learning how to run a laser, I really don’t think you can beat the cheaper diode engravers.

I do plan on upgrading to a CO2 laser at some point. I want to use it to cut light-weight plywood ~1/4" and acrylic.

Hope that helps answer your question.

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Thank you @niget2002, I think I am going to try and start the way you described. I don’t know where I’ll end up of course, but therein lies the fun.

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Well my ‘cheap’ Chinese laser engraver arrived (£180). Took me about 2 hours to build/set up. Honestly, it is pretty well designed and there was a reasonable video too. The control board appears to be an Arduino Nano (or clone, because it doesn’t say ‘Arduino’ on it) and the firmware is GRBL. I dragged an image into the supplied software (Engraver Master I think it’s called) and hit go.

IMG_0387
IMG_03872016×1512 1.02 MB

61928012348__D9588DF5-1D3F-4BFD-8C83-69552C96C06D
61928012348__D9588DF5-1D3F-4BFD-8C83-69552C96C06D2016×1512 1.06 MB

Honestly, I was shocked at the quality. I was quite prepared to repack and return, so credit where it’s due, this is a perfectly adequate piece of kit. I also installed LaserGRBL, and this works too, so I’m not tied to any of the supplied software. Plus, although I can’t see the beam with the supplied goggles (this encourages me, although I don’t look at it more than necessary), I can take pictures that look ultra cool.

Overall, this has satisfied me for now. I will learn what works and what doesn’t, then when I’ve decided how I’m going to incorporate this into jobs, I’ll make a decision on whether I need to laserify my MPCNC :smiley:

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That looks pretty much identical to my laser.

The cables start to get in the way when doing larger burns. I fixed this by zip tying mine to a retractable key-chain like used for security badges.

I have a video that talks about some of the things I changed on mine:

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