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Yeah, my larger point is that there are already plenty of ways to cut metal in a home workshop. I don't see how a laser would be an improvement on any of those

Yeah, my larger point is that there are already plenty of ways to cut metal in a home workshop. I don't see how a laser would be an improvement on any of those, unless the goal is to CNC with extremely tight tolerances, but even then... it seems unlikely that you'll be CNCing blocks of metal, more likely just 2D cuts from sheets of metal, which is pretty limiting. It would certainly be fun for some stuff, but I think the danger level of a super high power laser detracts from the fun. More powerful cutting lasers would definitely be great for industrial use cases.

mft_ 2y ago
You're right that such things already exist; I think it would offer two incremental improvements: * for wood, faster and/or thicker cutting, vs. existing CNC laser cutters * for sheet metal, neater/cleaner cutting (i.e. cleaner cuts, higher tolerances, less subsequent prep-work needed) perhaps in a smaller neater machine, vs. existing CNC plasma cutters. Especially within the context of a CNC machine, I wouldn't be overly concerned about safety - all of the more powerful CNC laser cutters I'm aware of already come with an exclosure - both for laser safety, and to constrain smoke (before it's vented safely).
83 2y ago
The precision of a laser cutter would open up a lot of possibilities. Particularly making things that slot together with tabs - like fabbing my own welding squares and fixtures where a cnc plasma cutter would leave too rough an edge to have them slot together accurately.
- coder543 2y ago
  Can't you buy a CNC mill/router that can cut metal more precisely than a CNC plasma cutter?
  - 91bananas 2y ago
    Completely different processes for completely different things.
    - coder543 2y ago
      Yes, and a laser cutter is also a completely different process for completely different things... yet you can still do some of the same things, and a CNC mill would be more appropriate for smooth cuts than a CNC plasma cutter.
  - mrWiz 2y ago
    Not cheaply, which was part of the OP's post.
    - coder543 2y ago
      Yes, for relatively cheaply. I’m not talking about a 5-axis CNC mill, and I’m not saying it’ll be fast. But a laser cutter is not fast either, and even if lasers get more powerful… a really powerful one is unlikely to be “cheap”.
      - alanbernstein 2y ago
        Of course it depends on what you're doing, and what you're comparing to, but in my experience, laser cutting is the fastest option for hobby-level fabrication.
  - bsder 2y ago
    Tormach metal CNCs are $10K+ and take up a lot of floorspace. A lot of people also cut sheet metal which a CNC tends to be terrible at.
    - coder543 2y ago
      We're talking hobbyist grade stuff here. People mount router bits on $400 CNCs and cut metal all the time. Not $10k: https://youtu.be/w26DHMccicE?t=637 https://youtu.be/w26DHMccicE?t=637 Even though it's cheap, the cuts still look pretty smooth and precise. I can't speak to the safety, as I would hope a $10k CNC would have more safety features.
      - bsder 2y ago
        They cut aluminum. Generally not well. This part is actually a typical good result in spite of how bad it is: https://youtu.be/w26DHMccicE?t=731 https://youtu.be/w26DHMccicE?t=731 Deflection is bad. Repeatability is poor. etc. If you put even mild steel on that, that machine will have no hope.
        coder543 2y ago
        Okay, but if you’re expecting a magical new diode laser to cut steel any time soon… good luck. That’s what most of this discussion is about. I think starting with a cheap CNC is more likely to work out.
        bsder 2y ago
        o_O? The article literally has a video of the laser actually cutting stainless steel (aka the Devil's chewing gum). The title says "melt steel". That was the practically the whole point of making these kinds of laser. Video link: https://youtu.be/SFXmFNTviRI https://youtu.be/SFXmFNTviRI
        coder543 2y ago
        Yes... but you can't buy it. It's in a research lab. And even once it goes into production, what are the odds that it's going to be affordable? They can probably sell every laser they can produce at a very high price for a long time before supply catches up to demand, even though this is supposed to be easy to manufacture. I'm just extremely skeptical of a steel-cutting laser mill being cheaper than a $10k CNC any time soon. Hardware is hard. Semiconductors are even harder. As far as I can see, the article provides no indication of when they even hope to bring this product to market, which is never a good sign. https://xkcd.com/678/ https://xkcd.com/678/ I would love to be wrong. And really, that video is unsatisfying. They show a mark on the steel, but -- as far as I saw -- they never even show any steel piece that was cut out by the laser. Maybe the steel melts at the very surface... but it may not be possible to cut through a piece of steel unless it is thinner than a piece of paper? We have so little real world information on this laser.
  - 83 2y ago
    You can't cut sharp inside corners using a cnc mill (round bits), as one would want for tabbed fixtures. Most sheet good are too large to be placed on or moved around by a cnc mill table. CNC milling is a slow process (unless you can drop six figures on one). CNC mills take a lot longer to setup and program, and also require more skill to have a successful result (no chatter, not breaking bits, ramping into the cut on interior features). Good CNC mills that can handle steel are massively heavy and large machines which makes transport and setup difficult for the home machinist.
alanbernstein 2y ago
I use a 120W laser cutter for practical, precise, CNC projects all the time. I use a lot of 1/4" acrylic because it's a good material for this class of machine, but it's not the best option, structurally. If I could do the same with 1/8" or 1/16" steel, I would likely switch to that for almost every project. I love the idea of using a mill/router instead, but IMO the more complicated process is fundamentally more dangerous. If a reflected beam can conceivably pierce the enclosure though, hmmm...

mft_ 2y ago

You're right that such things already exist; I think it would offer two incremental improvements: * for wood, faster and/or thicker cutting, vs. existing CNC laser cutters * for sheet metal, neater/cleaner cutting (i.e. cleaner cuts, higher tolerances, less subsequent prep-work needed) perhaps in a smaller neater machine, vs. existing CNC plasma cutters. Especially within the context of a CNC machine, I wouldn't be overly concerned about safety - all of the more powerful CNC laser cutters I'm aware of already come with an exclosure - both for laser safety, and to constrain smoke (before it's vented safely).

83 2y ago

The precision of a laser cutter would open up a lot of possibilities. Particularly making things that slot together with tabs - like fabbing my own welding squares and fixtures where a cnc plasma cutter would leave too rough an edge to have them slot together accurately.

coder543 2y ago
Can't you buy a CNC mill/router that can cut metal more precisely than a CNC plasma cutter?
- 91bananas 2y ago
  Completely different processes for completely different things.
  - coder543 2y ago
    Yes, and a laser cutter is also a completely different process for completely different things... yet you can still do some of the same things, and a CNC mill would be more appropriate for smooth cuts than a CNC plasma cutter.
- mrWiz 2y ago
  Not cheaply, which was part of the OP's post.
  - coder543 2y ago
    Yes, for relatively cheaply. I’m not talking about a 5-axis CNC mill, and I’m not saying it’ll be fast. But a laser cutter is not fast either, and even if lasers get more powerful… a really powerful one is unlikely to be “cheap”.
    - alanbernstein 2y ago
      Of course it depends on what you're doing, and what you're comparing to, but in my experience, laser cutting is the fastest option for hobby-level fabrication.
- bsder 2y ago
  Tormach metal CNCs are $10K+ and take up a lot of floorspace. A lot of people also cut sheet metal which a CNC tends to be terrible at.
  - coder543 2y ago
    We're talking hobbyist grade stuff here. People mount router bits on $400 CNCs and cut metal all the time. Not $10k: https://youtu.be/w26DHMccicE?t=637 https://youtu.be/w26DHMccicE?t=637 Even though it's cheap, the cuts still look pretty smooth and precise. I can't speak to the safety, as I would hope a $10k CNC would have more safety features.
    - bsder 2y ago
      They cut aluminum. Generally not well. This part is actually a typical good result in spite of how bad it is: https://youtu.be/w26DHMccicE?t=731 https://youtu.be/w26DHMccicE?t=731 Deflection is bad. Repeatability is poor. etc. If you put even mild steel on that, that machine will have no hope.
      - coder543 2y ago
        Okay, but if you’re expecting a magical new diode laser to cut steel any time soon… good luck. That’s what most of this discussion is about. I think starting with a cheap CNC is more likely to work out.
        bsder 2y ago
        o_O? The article literally has a video of the laser actually cutting stainless steel (aka the Devil's chewing gum). The title says "melt steel". That was the practically the whole point of making these kinds of laser. Video link: https://youtu.be/SFXmFNTviRI https://youtu.be/SFXmFNTviRI
        coder543 2y ago
        Yes... but you can't buy it. It's in a research lab. And even once it goes into production, what are the odds that it's going to be affordable? They can probably sell every laser they can produce at a very high price for a long time before supply catches up to demand, even though this is supposed to be easy to manufacture. I'm just extremely skeptical of a steel-cutting laser mill being cheaper than a $10k CNC any time soon. Hardware is hard. Semiconductors are even harder. As far as I can see, the article provides no indication of when they even hope to bring this product to market, which is never a good sign. https://xkcd.com/678/ https://xkcd.com/678/ I would love to be wrong. And really, that video is unsatisfying. They show a mark on the steel, but -- as far as I saw -- they never even show any steel piece that was cut out by the laser. Maybe the steel melts at the very surface... but it may not be possible to cut through a piece of steel unless it is thinner than a piece of paper? We have so little real world information on this laser.
- 83 2y ago
  You can't cut sharp inside corners using a cnc mill (round bits), as one would want for tabbed fixtures. Most sheet good are too large to be placed on or moved around by a cnc mill table. CNC milling is a slow process (unless you can drop six figures on one). CNC mills take a lot longer to setup and program, and also require more skill to have a successful result (no chatter, not breaking bits, ramping into the cut on interior features). Good CNC mills that can handle steel are massively heavy and large machines which makes transport and setup difficult for the home machinist.

alanbernstein 2y ago

I use a 120W laser cutter for practical, precise, CNC projects all the time. I use a lot of 1/4" acrylic because it's a good material for this class of machine, but it's not the best option, structurally. If I could do the same with 1/8" or 1/16" steel, I would likely switch to that for almost every project. I love the idea of using a mill/router instead, but IMO the more complicated process is fundamentally more dangerous. If a reflected beam can conceivably pierce the enclosure though, hmmm...