More on IC Self-Reproducing Machine Tools

A 2-stroke. And who will that self-replicating machine build spark plugs? Build an ignition? Build radial sealings? Build ball bearings, or even worse needle bearings? Cast aluminium and steel?

That will be the most complicated. The smaller the worse.

IC engines on the road? Never seen that, sorry. ;-)

Nick

2005-11-24

To: news:rec.crafts.metalworking

Glad to hear it, Doug. 'Hope you enjoyed the day.

First, make sure you have an "off" switch on those things, or we could wind up paving the whole country with little Chinese mill/turn machines.

It sounds like one hell of a show. But why would you want this advanced technology to run on old fossil-fuel power?

-- Ed Huntress

(snip greetings)

Yeah, I have tried some web boards. Usenet's my thing. I am back.

Erk. I had too much espresso Yesterday.

Paving the country with them? Or paving their country with us? Brrrr.... :o

No actually, since no "factory worker robot" exists, duplicating human abilities, there is no "grey goo" problem with MTSR. The whole thing is rate-limited by our puny ability to transfer expertise to each other, since the only truly universal constructor in the proposal is us.

Because MTSR is actually centuries old technology. I'm a revivalist. It's been, like, nearly ten generations since the Industrial Revolution. Much has been lost. Self-upgrade was how machine tools were

*born*.

To repeat, machine tools usually use electric motors as prime movers because we have the infrastructure. There's no infrastructure on Mars and beyond. Nowhere to plug in.

So, do we build an engine for a lathe, one for a mill, etc. or a line shaft? No. We build a single universal machine that can make parts for its own engine. Or maybe a series of engine, rotary, and slide modules. It seems the most efficient thing to do. And we hold the keys to the pump, not that a machine tool could take them from us....

Doug

I have seen micromachined electric motors, air turbines, and gas turbines. Most folks I know consider gas turbines IC, because the "engine" they consider includes the compressor, burner cans, and turbines together, hence IC.

I have yet to see a micromachined piston engine, either 2 or 4 stroke.

One reason for turbines is that the small size allows VERY high rpm without excessive inertia loads. Also, the very tiny valves for a 4 stroke would be more of a problem than for a turbine.

The blades > 2005-11-24

Harris has made one, coupled to a generator. It was designed to be a power source to replace batteries. Runs on ethanol. Fits in a 4mm cube.

Kevin Gallimore

It's an interesting concept. But before you do machine tools, try doing Jessica Simpson. You'll have a much bigger market.

-- Ed Huntress

Rack and pinions are neat - and naturally the mirror that is controlled to create pixels... I don't know - but suspect (as it was planned at one time) that the new Sony super duper - double density HDTV twice the pixels - uses that technology.

Life member - Electron Device Society IEEE Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder

D> I have seen micromachined electric motors, air turbines, and gas

Go research model aircraft 2-stroke diesel engines. Some are literally a piston, a crank, and a cylinder with a carb. No plugs, injectors, valves, linkage, timing, or anything else. Just have to spin the crap out of it to get started. You could couple that to an air motor for starting, then the air motor could act as a vane-style compressor once the engine started. But I think that style of engine is limited in displacement.

This massive tome is now available on the web:

The Dougster

Yes, the vane style is good for high speed, good power density, and a high pressure input, but performs miserable as a compressor. An IC vane style motor has been constructed, I believe. I forget what it is called. Ericsson Cycle? I don't think that is right.

The 2-stroke diesels might be a good choice. The Army is going all diesel, I believe. Do 2-stroke diesels scavenge with air/fuel or do they use an injector? I know the little ones do, but how about larger ones? .49 cu in is enough for my Unimat One, or a small machine, not much more. Scale is still an issue here.

It's nice to see some traffic on this thread! Were you all napping after that big Thanksgiving dinner?

Doug

Hm. Thank you, Don.

Freitas is heavily into nanofabrication. But he concentrates on molecular assembly, not micromachining. And in the MA field, power generation is a long way off.

Gotta love that surface to volume ratio and other scale effects. High RPM without a lot of stress makes for a reliable engine.

Doug

The little ones I was alluding to depend a great deal on momentum. The momentum of the flywheel to force 'em through a complete cycle, and the momentum of the column of air entering/exhaust leaving to scavenge. Carburated, so air/fuel mix. Like I said, these are small displacement--as in fractions of a CC. If you go into larger sizes you'll likely need to go with injection. Many of the Military's HET trucks run from Detroit Diesel two strokes. These are often V8 engines with a blower mounted on top, between the banks of cylinders. Air is inducted through ports, with the exhaust valved at the top. Fuel is injected with unit injectors, which seem to be a lot less touchy than centralized high pressure systems. For a critter like that to replicate, it needs to be able to cast a rather complex engine block, machine a blower with a helix shape and tight tolerances, plus make ball bearings, gears, rubber seals, and ported cast iron liners. May not be doable. Could be more practical to use sterling engines and settle for the low horsepower.

I've been rebuilding my apartment after a failed move.

Why do you say that?

I say electric machines are difficult to produce with machine tools because an intermediate step, fabrication of a stamping die, is required to make the many laminations, although I suppose they could be laser cut, but a laser is not a machine, it's a device. Heck, I guess an electric motor is not a machine; it's a device, too.

Including other technologies makes self-reproduction more difficult.

Doug

I think you're making the same common mistake most people make, and omitting the things that will kill your idea dead.

a/ raw materials to work ready alloys and castings

This is a bitch, you need a geologist, a miner, a metallurgist, a chemist, and a handful of labourers, and a bunch of time....

b/ lathe bed, piece of cast iron with parallel sides, brunel made one by rubbing three sheets of iron together with grinding compound, took him ___months___

This is a bitch, those labourers are in for more back breaking work

c/ precision screw threads, make and repair taps and dies.

This is a bitch, any fule can cut a thread of dimensions and proportions of their own choosing, making one that works for different materials and is good enough so __any__ size x nut will fit ___any___ size x bolt and stays torqued until you put a spanner on it is tough

e/ ball bearings

This is a bitch on heat, you want a REAL modelling challenge make two identical roller bearings from stock metal that have 10% of the performance envelope of shop bought ones

f/ lubricants

This is tougher than it sounds, 1920s lube oil won't keep a modern high performance engine alive

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My answer to you question is this.

3 x identical 40 containers, each a complete identical shop, each powered by an identical petter CS type compression ignition motor powering identical ac alternators, dc dynamo and compressors, with a backup prime moves as steam engine

3 x more identical containers containing every conceivable spare for the above (don't forget mundane stuff like gasket paper)

3 x more identical containers containing a variety of fuels and lubes

3 x more identical containers containing identical smelting and foundry shops

30 x more identical containers containing raw materials

----------------------

yeah, what you want can be done, but think coastal shipping size "base", not something you can load in the back of a pick up.

Thanks, Guy, for your comments on scale. I am not afraid to think big.

Neither is NASA. They are talking about heavy lifters, and they started this whole self-reproducing machine shop thing back in the 1960's.

A recent proposal for a space elevator could make a lot of difference.

The Dougster

NASA is funny

was it NCSA before?

anyway, USA were the speed kings, X1 etc, but the military ICBMs came along and NASA went heavy lifter, not winged scramjet, and the rest of the planet followed.

I'm intrigued that the japanese and chinese and everyone else is following the "stick it on top of a big rocket" approach to orbit.

Well the Chinese got the hardware and software from the us (violations) from a company that was putting up a bird and they didn't want crashes like the Chinese were getting...

Martin Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder

Guy Fawkes wrote:

Hey, be nice!

The Chinese invented the rocket in 1232AD :-)

Mark Rand RTFM