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Comment by Jack000 | Hacker News Reader

I'm always surprised how much these things cost. A 3 axis CNC is basically a 3 degree-of-freedom robot, yet only costs a few hundred dollars. I think we'll see mobile autonomous robots come into people's homes only after they:

- fall to low thousands price range

- do something useful (ie. not just a "social robot")

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I think you forgot a zero there. A 3 axis CNC mill usually costs a few thousands of dollars. There are some crappy CNC engravers and dirt cheap 3D printers but the rigidity requirements are so low that they are a completely different class of machine.

There is a pretty big range of prices. The cheap Chinese ones aren't necessarily well built but they work fine for hobbyist stuff.

Motors, motor controllers + motion system are cheap enough for affordable home robots I think. The problem is automating actual tasks with the limitations of the motor controls.

Unfortunately the controls problem gets much harder in a non-rigid system. Now you have to solve autonomy AND overcome poor sensing and manipulation.

Cheap 3 axis CNC machines are very dumb (I broke a home built machine once because there were no end stops and I programmed it wrong (stepper motors are very powerful)).

And there are professional CNC machine costing waay more than this robot.

I think you are comparing apples with oranges. The price is also for a development kit. So I can imagine the price could be at least half if they sold a few thousand of them.

a CNC does not have a perception/reaction loop and is no more a robot than a dot matrix printer might be. the cheap cnc machines don’t even have closed loop control. it certainly isn’t solving any of the right problems.

A CNC machine is as much a robot as an industrial arm is. I suspect you might specifically mean "autonomous robot"?

is anything with a motor a robot? of course there is a hierarchy, with the stepper-driven open-loop machine he gave as an example being further down the ladder.

No, I mean literally. Industrial arms aren't necessarily any more complex than CNC machines. They may not have any more motors. They perform tasks of similar complexity, with similar programming models. We call them "robot arms" quite happily.

this is inaccurate in a variety of dimensions. they have more complicated gearing (strain-wave) and and perception systems for safety (for nearby humans) and positioning (unless you can get the stunning tolerance stacking that the automotive industry gets.)

I suspect the cost of the (presumably) Lithium-Ion battery is a significant chunk of change. Also, economies of scale in this form factor.

You can get cheap open source robots if you build it yourself.

They still can't do anything useful though.

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