Update: What You See Is What You Laser Cut

If there’s one thing about laser cutters that makes them a little difficult to use, it’s the fact that it’s hard for a person to interact with them one-on-one without a clunky computer in the middle of everything. Granted, that laser is a little dangerous, but it would be nice if there was a way to use a laser cutter without having to deal with a computer. Luckily, [Anirudh] and team have been working on solving this problem, creating a laser cutter that can interact directly with its user.

The laser cutter is tied to a visual system which watches for a number of cues. As we’ve featured before, this particular laser cutter can “see” pen strokes and will instruct the laser cutter to cut along the pen strokes (once all fingers are away from the cutting area, of course). The update to this system is that now, a user can import a drawing from a smartphone and manipulate it with a set of physical tokens that the camera can watch. One token changes the location of the cut, and the other changes the scale. This extends the functionality of the laser cutter from simply cutting at the location of pen strokes to being able to cut around any user-manipulated image without interacting directly with a computer. Be sure to check out the video after the break for a demonstration of how this works.

This system could be great not only for laser cutters, but for any CNC machine normally controlled by a computer interface. By interacting directly with the project it’s less likely you’ll end up with something that’s just slightly the wrong size or slightly the wrong dimensions. If you’re new to CNC you might want to check out this guide, or maybe you just want to turn your existing CNC machine into a chess robot.

41 thoughts on “Update: What You See Is What You Laser Cut

    1. Researcher 1: Why do I have to wait 3 months for this quick prototype part that doesn’t even have to be precise?
      Laser cutter 1: I’m having it rapid prototyped at a specialist who’ll hire a specialist-CAD guy for a few thousand bucks and they will send it back in mere months, no worries.

      Your turn.

          1. While plants are known for producing free oxygen as a waste byproduct, they also consume it. During the day or when a plant is receiving light, the chloroplasts (the green organells that make plants green) convert CO2 and water into sugars that the cell can use throughout the day and night. While the plant is receiving light, it typically produces more oxygen than it consumes burning its sugars.

            At night, there is no light and therefore no mechanism to create sugars as needed. As a result, the plant will use its sugar reserves to keep its cells alive. When the plant burns the sugars, it produces carbon dioxide.

            If you ever get into the planted aquarium trade (or do a bit of research), you’ll find that folks will turn off CO2 injection systems at night and turn on ambient air aeration. This is because the plants in heavily planted tanks can consume all of the oxygen (which is bad for fish) as well as release large amounts of CO2 that, in water, becomes carbonic acid that can drop the pH and kill sensitive fish or react with alkaline minerals in the tank and produce toxic chemicals. By turning off the CO2 the plants would have used during the day and aerating the water, you reduce the amount of carbonic acid being created and provide oxygen for both the fish and plants.

    1. Yeah, this. People think that the hazard is getting burned when it’s their eyes at risk. And don’t use sunglasses/cheap (unrated) “laser goggles” from Ebay.

      Machinist 1: Why is your part all wavey and looks like children made it?
      Machinist 2: I’m blind and can’t see what I’m doing.

        1. Nope. Nope nope nope nope nope. While acrylic and glass do absorb a good deal of IR, they are in no way rated to handle high output lasers. If you are working with anything about a Class I, actual laser goggles should be used. Once your eyes are damaged, it is exceedingly rare to actually recover fully – it isn’t worth the risk of just assuming your standard glasses will absorb enough IR energy that it is safe.

          1. Yep. Yep yep yep yep yep.

            What do you think the ‘real’ ‘official’ safety glasses are? Tell us what the filter is. If you want to pay $100 for what the seller sources for 50 cents, go right ahead.

            Regardless of the type of laser, the glasses are to protect from scattered reflections (2nd line of defence). If you’re sticking your face in front of the full power beam, well, sucks to be you.

            Normal safety glasses vs 60W CO2 laser: http://www.youtube.com/watch?v=3bSv6BR-RG8

            If it takes you 5 seconds to notice the ball of fire in front of your eyes, perhaps lasers are not your thing.

          2. If you put just about anything in front of a 60W laser it is going to go up in smoke. Given that the camera has an IR filter on it, we can’t see the amount of IR that is actually going through the glasses (not to mention that absolutely nothing is measured). We don’t know how much IR the glasses are attenuating vs admitting nor how they compare to rated laser safety glasses.

            Using standard safety glasses in lieu of laser safety glasses is like using a candy wrapper for a condom – sure, it might work in a pinch, but using something in a way it was not designed to be used is asking for trouble.

          3. The argument from ignorance is always a good stance.

            The amount of IR (at 10640 wavelength) going through those glasses is zero. There’s a reason those glasses are on fire and the reason is because polycarbonate & acrylic plastic (most organics really) are really really good at absorbing that wavelength.

            Guess what they make the protective windows on lasers out of.

            I’ll wait while you think about it.

            As an aside, the reason clear isn’t often used is because the point when the action happens gets really really bright. Makes it hard to look at.

            But hey, if you want to fork out a few hundred dollars where a few would suffice, go right ahead. You’re probably one of those people who buys the extra special UV blocking sunglasses. Go ahead, the economy needs suckers like you.

            (Tip – all sunglasses, yes even the really cheap ones – block over 99% of UV.)

        2. “…most lasers are infrared CO2…”

          Yeah, but from the video I’d bet that this one is likely a couple of watts and probably 445nm (visible blue).

          A counterintuitive problem with laser safety glasses in the visible spectrum, is that they filter out the laser wavelength thus giving the false impression that the laser is off even if it is on. So while it may save your vision, people might pass their hand thru an active beam, catch clothing on fire, etc.

        1. The more blue you see the less of it you see?


          If I look at the sky long enough will it go away?

          Just looked outside, and the blue sky is gone! I can see stars and stuff! Woohoo, it works!

          1. I think he’s talking about how sufficient amounts of short-wave light can cause general degeneration of your eyesight, hence the blue-light warnings you see on some laser products.

        2. Shorter wavelengths are ionizing. Blues, violets, UV, X-ray, ect all have the ability to blow apart molecules into their respective parts. A more common example of this is short wave radiation causing cancer – the ionizing radiation damages DNA molecules which then causes cellular defects. In the case of the eye, the radiation can also blow apart the pigments that allow you to see color, effectively making you go blind. The blue cones in your eyes are most receptive to shorter wavelengths, so they will accept the energy to the point that they are destroyed most easily. Given enough energy, you will lose the ability to see blue (and possibly all other colors or light in general).

          TL;DR – Short wavelength radiation destroys blue pigments in the eyes easily above certain energy levels (commonly found in really bright blue lasers).

  1. Bumbug! If you want to interact more closely with the laser cutter, then why not a laser pantograph?

    Wouldn’t it be cool to use a Wacom tablet to control the cutter? Stylus pressure could correspond to laser power. Of course, this is pretty obvious, and has probably already been done…

    1. There is already such a thing… Well, for torch cutting and plasma cutting. They are called bug-eye burners or shape tracers. Draw out what you want to cut with a sharpie on a piece of paper and the head will follow the track. The torch is connected mechanically to the head. Often there are multiple torch heads on a machine to cut out a bunch of parts.

  2. I worked with this project. Ofcourse, we use the laser-safety glasses here! We mention “2w laser- with laser eye safety equipment” on the video link<- haha i DONT want to go blind and use Lechal itself.

    The goal here was to fuse the strength of hand manipulation and augmented reality to eliminate the use of external computer.
    Noirwhal: Agreed, its an early prototype we did in <100$ in total.

    First ever iteration of the project- http://fluid.media.mit.edu/projects/clearcut-augmented-laser-cutter

  3. Just an idea… You know laser projectors, for drawing patterns with a laser in nightclubs etc? Why not implement that on a cutting laser? Only, of course, the laser is on reduced power. That way, it could project the intended shape onto the material, and you’d be able to see it in situ. WYSIWYG. Haven’t used that acronym in a while!

    Assuming you can throttle the power to lasers like that. Otherwise I suppose you could just use a diode laser for it.

    1. Laser cutters are several orders of magnitude slower than a laser projector. You could actually leave it at full power and use the projector and it wouldn’t burn anything, the light energy is moving way too fast for that. The problem is, it wouldn’t be truly WYSIWYG, the galvos (motors that aim the mirrors) used in a laser projector aren’t very repeatable, especially at different speeds. A typical 30kpps (thousand points per second, the measurement of speed used in galvos) projector, if you give it the same image as a 1 kpps, 6 kpps, and 12 kpps, none of them will line up properly. A laser cutter itself measures its speed in mm/s. My 200 mW, I typically run it at 0.5 mm/s or so…

  4. I never realized how easy scanning an image could be with a laser cutter. Seeing how you can use a phone to scan an image and make a replica of it is really fascinating. I can see how valuable this service would be to a business owner with a logo. Thanks for sharing, I’ll pass this along to my cousin who has her own logo and perhaps she will find it useful.

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