Anyone running a laser on their 3D Printer?
I’m looking to double up my 3D printer as a laser cutter, but want to understand what laser power I should buy…
What is the capabilities of a 3.5W blue laser compared to a 5W and 7W?
In addition, what protective gear is needed, and where to source it from Europe?
What are you interested in cutting/engraving?
Yeh don’t think you will be laser cutting but laser engraving definately
@michael_hughes
My 2W 450 NM pointer will eventually burn through a cd case. It takes about 15 seconds to pierce all the way through.
It makes a big sloppy hole.
I think you’ll want all the wattage you can get to ensure that the plastic ablates rather than melts, so that the heat affected zone will be minimalzed.
The slower the cut, the more heat will conduct.
I bought it for $260 four years ago.
With the mentioned wattage you will be able to cut paper and thin cardboard (~2mm darker material will work better) and engrave a couple of different materials like wood and PMMA .
More wattage is better 
it’ll allow you to move the beam faster - which will result better cuts.
You should at least blind the build volume of the printer so you are not affected by the scatters light. In addition you should use protective goggles which can be found on amazon.
Also you have to take into account that you BURN away material with the laser and therefore you have to deal with a lot of fume and at least CO2 and CO so some kind of ventilation is mandatory.
If you play around please stay away from:
PVC,PTFE - produces hydrochloric acid & chlorine gas
ABS,PA,PU - produces hydrogen cyanide
You should check out the cnc forms for things like inventables or shapeoko: Lot of those guys put lasers on their cnc’s, and have sorted out a lot of this already. For example, I learned a lower wattage laser can actually cut faster than a higher wattage one, since the beam is smaller and more focused. I’ve thought about putting one on my cnc fora while now, but that whole ‘laser/fire’ safety issue has kept me scared off. Plus you need really good venting, which I could do in my workshop (where the cnc lives) but not in my art room (where 3d printers are).
I was hoping to see what capabilities each wattage had. 2W 2mm paper, 5W 4mm cardboard, 7W 2mm acrylic or 2mm plywood, etc, the above being hypothetical in this case…
@Justin Nesselrotte, I’m not targeting a laser for anything specific, but wanted to see if it would add any value. From the folks are saying here, I would be engraving, and not really cutting… So ok, i guess I’ll have to decide if that’s what i want
+Carsten Müller, thank you for rasing and of the fume dangers that could be produced.
@Panayiotis_Savva
Talk to someone who knows laser cutting better than we do here.
Surely there is a laser cutting forum.
@Eric_Pavey “I learned a lower wattage laser can actually cut faster than a higher wattage one, since the beam is smaller and more focused.” Thats true if you are working with a bare LED without any optics. But who would do so? The correct focus is as important to laser cutting as the correct cutter speed to milling.
2W will do standard printer paper up to heavy stock. Note that cutting white paper is kind of a hassle: you have to focus and hold for like half a second before it blackens and burns, but at that point you can take off at a fairly good clip because you’ve already got a burnt spot that absorbs the light well.
I will argue that more wattage is better, because at powers this low, the amount of time you have to spend dwelling on a point to cut all the way through, increases the number of times the work piece, if paper or wood, bursts into flame.
I made a freeform laser for my wife to burn ‘happy holidays’ into our holiday cards this year, using a 1W red and a 2W blue, and quite a number of them ended up in flames rather than being usable cards.
@Carsten_Muller : Yah, I should have put in a caveat: “I don’t know what I’m talking about, I’m just repeating stuff other people said” 
@Panayiotis_Savva I have thought that you would like something like that but unfortunately thats not as easy as it seams. To many factors are involved. Starts with the wavelength, the focusing or lack of, the reflectiveness of the material in the specific wavelength (Thats why white paper is hard to cut with visible light) and even the humidity of the material plays a significant role.
Check out this video about putting a laser head on a 3d printer.
If you are just looking to cut paper thin objects and possibly thicker cardboard just buy a Cricut. The cost of the entire machine is less than a massive laser. It’ll also do some low level engraving and 2D drawing for you.
If you are looking for the all in one, copy the tool head design and slap it on your printer. I think it is basically an exacto knife blade.
TONS of people do really unsafe things with lasers and 3d printers. Even some well-regarded expert members of the 3d printing community are big laser safety offenders in public and set bad examples for newbies. Some things you need to be aware of before you bolt a laser onto a 3d printer:
It’s basically a low-power death ray. It can start fires or hurt anyone in line of sight. The better the laser (eg focus/power) the more dangerous it is as an energy weapon. Kids, pets, etc are at risk. Are you sure you want to bolt that onto an under-engineered hobbyist contraption made of flammable plastic and low-cost Chinese parts? Just think about the general reliability of 3d printers for a bit before you commit to the laser combo printer. What happens if a FET sticks on, or a structural part cracks, or the steppers lose position? It’s important to understand that 3d printer controllers cause much more vibration than true laser cutter controllers, due to use of corner jerks, yet have fewer safety features.
Blue lasers can cause skin melanomas due to the higher photon energy than other laser colors, and like all cutting/etching lasers, will cause INSTANT blindness even without full power or focus. The highest risk is obviously when the beam goes somewhere it’s not supposed to go, such as a direct reflection or if the laser mount fails due to vibration. But it’s not just a “stray beam” safety issue. Active laser cutting / etching throws a LOT of lower-intensity flare all around the room, which is still dangerous over long-term exposure. Just about every video you’ll find on YouTube of people running diode lasers has the camera sensor picking up tons of blue laser flare. That same flare is hitting their skin and (hopefully) laser safety glasses. DO NOT OPERATE A LASER CUTTER/ETCHER WITHOUT A FULL ENCLOSURE. This is a SERIOUS safety issue. It is stupid to operate an open-air cutting laser, full stop.
The typical bolt-on diode lasers you can buy online, which are marketed for attaching to 3d printers and CNC mills, are quite literally illegal to buy/sell in the EU and US and many other developed countries. Enforcement is very lax… but cutting/etching lasers are legally controlled products due to massive consumer safety hazards. There are strict criteria required for how they must be enclosed and interlocked according to power level. Anything over 0.5w (depending on country) needs to be fully enclosed, and the laser needs to be interlocked with the enclosure and e-stop button, plus a safety key to prevent unauthorized/inadvertent activation of the laser.
Laser safety glasses may or may not be designed for the wavelength and power of your specific laser. Do you know how to match laser glasses ratings to laser specs? Can you trust the laser vendor to provide the correct specs? Did your laser glasses come from a reputable vendor?
Lasers produce nasty, nasty fumes when cutting nearly anything. Wood/paper smoke itself is bad but there’s also stuff like plywood glue and paper additives to consider. You MUST use ventilation. Maintaining your enclosure with negative pressure and ducting the exhaust directly outside is strongly, strongly recommended.
When operated properly, low power diode lasers are worse for fire safety than high-power lasers with focusing optics. A high-power laser instantly vaporizes material and the fumes are quickly carried away, so there is never enough hot material in one place to be a meaningful fire risk. A low-powered laser tends to burn through the cut rather than vaporizing, which means more kerf converted to out-gassing of nasty/flammable compounds, and more heating of edge material along the cut.
Air assist (in addition to ventilation) is really important to carry away fumes and smoke from the active cut. Remember, when solids light on fire, what is actually burning is reactive vapors outgassed from the solid – and converting solids to vapors is literally the purpose of the cutting laser. Without air assist, the laser light has to travel through more smoke/vapor from the cut, which puts more heat into flammable fumes and less into the cut, further exacerbating issues with burning rather than vaporizing material.
This is an area where hobbyists just do grossly inadequate stuff and put themselves and their homes/families at risk. I personally recommend you don’t do it. It CAN be done safely, but by the time you add all the necessary printer upgrades to do it right, you might as well have just purchased a dedicated laser cutter.
@Ryan_Carlyle you are absolutely right. In think I’ll go for a dedicated laser cutter, which will be produced based on EU regulations.
Thanks for opening my eyes to the real issues people could face, such as blindness…