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I know little about materials science, but I know that metal grades vary significantly in performance (and cost). Instead of saying, "Any part can be made via

I know little about materials science, but I know that metal grades vary significantly in performance (and cost). Instead of saying, "Any part can be made via a 3d printer," shouldn't it be said that, "Something in the same shape and size of any part can be made using such a printer."? It's not like we can print out a new camshaft and drive the car for 5K miles using it, right?

jacquesm 17y ago
Spot on. That's exactly where this whole article fudges the facts. You're 'printed' camshaft might even fit but it would explode the moment you tried to crank up your car. The metal parts that can be made using this process are 'sintered', which is an expensive way of saying that they consist of compressed powder. Such parts have compressive strength but usually not much tensile strength.
a-priori 17y ago
As other people have said, he's mostly using this printer to print molds of the parts. These molds are then used cast the parts out of whatever grade of metal is up to the task.
- ShabbyDoo 17y ago
  Having once cast an aluminum cornbread pan in high school shop class, I can understand how using such a printer for mold making could be extremely useful. And, I can see how it could have niche uses in various industries. But, the people saying that the 3d printer will change the world as we know it (or whatever other grand predictions) haven't explained to me how it will be anything more than a great proto-typing/mold-making tool for casting/machining operations or customers of those businesses. Am I missing something?
  - jacquesm 17y ago
    That all depends on the speed of the machine, the price of the 'input' material and the versatility with which you can apply it (and the cost of the energy required to run it). If it is done 'right' (price point at or below casting, fast to the point where making a complex part would take a couple of minutes at the most and create any solid shape, even multiple parts in one go assembled and ready to go) then it would change the world as we know it in ways that I can only describe as science fiction. Drive the price down even further (to say below what it costs to mass produce castings) and you're looking at something where even the imagination will fail. Make it precise enough that you can create nano machinery and you get yet another level of technology that gets unlocked. It's hard to predict what any of that would be like, but I can see all kinds of good and bad stuff happening. Suddenly the blueprint is the machine, if you can think of it you can make it. Right now the barrier to entry to manufacturing is comparable to lets say big iron computing in the 70's. Think of this thing as the PC of manufacturing, suddenly everybody can quickly and easily make just about anything. Mold making is an art and terribly expensive, so for now prototyping is handwork or at best one-off CNC runs. To replace that by a process that would cost a very small fraction would upset quite a few applecarts. If it stays slow and expensive then it will be a niche technology, but the speed at which the prices are coming down and process speed goes up is very impressive.
- kragen 17y ago
  You can't cast a working crankshaft either; the surfaces won't be smooth enough. You can cast a "crankshaft" and then machine the surfaces down to the micron tolerances you need.

jacquesm 17y ago

Spot on. That's exactly where this whole article fudges the facts. You're 'printed' camshaft might even fit but it would explode the moment you tried to crank up your car. The metal parts that can be made using this process are 'sintered', which is an expensive way of saying that they consist of compressed powder. Such parts have compressive strength but usually not much tensile strength.

a-priori 17y ago

As other people have said, he's mostly using this printer to print molds of the parts. These molds are then used cast the parts out of whatever grade of metal is up to the task.

ShabbyDoo 17y ago
Having once cast an aluminum cornbread pan in high school shop class, I can understand how using such a printer for mold making could be extremely useful. And, I can see how it could have niche uses in various industries. But, the people saying that the 3d printer will change the world as we know it (or whatever other grand predictions) haven't explained to me how it will be anything more than a great proto-typing/mold-making tool for casting/machining operations or customers of those businesses. Am I missing something?
- jacquesm 17y ago
  That all depends on the speed of the machine, the price of the 'input' material and the versatility with which you can apply it (and the cost of the energy required to run it). If it is done 'right' (price point at or below casting, fast to the point where making a complex part would take a couple of minutes at the most and create any solid shape, even multiple parts in one go assembled and ready to go) then it would change the world as we know it in ways that I can only describe as science fiction. Drive the price down even further (to say below what it costs to mass produce castings) and you're looking at something where even the imagination will fail. Make it precise enough that you can create nano machinery and you get yet another level of technology that gets unlocked. It's hard to predict what any of that would be like, but I can see all kinds of good and bad stuff happening. Suddenly the blueprint is the machine, if you can think of it you can make it. Right now the barrier to entry to manufacturing is comparable to lets say big iron computing in the 70's. Think of this thing as the PC of manufacturing, suddenly everybody can quickly and easily make just about anything. Mold making is an art and terribly expensive, so for now prototyping is handwork or at best one-off CNC runs. To replace that by a process that would cost a very small fraction would upset quite a few applecarts. If it stays slow and expensive then it will be a niche technology, but the speed at which the prices are coming down and process speed goes up is very impressive.
kragen 17y ago
You can't cast a working crankshaft either; the surfaces won't be smooth enough. You can cast a "crankshaft" and then machine the surfaces down to the micron tolerances you need.