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Can't you buy a CNC mill/router that can cut metal more precisely than a CNC plasma cutter?

by coder543 2y ago

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.

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.