REPRAPS changing things in your scifi

[Simon_Jester]

It's a bit hard to build a nuke in your basement in any reasonable amount of time and in secret, even assuming that a replicator can make all that parts for you.

The assembly is not difficult if you can procure the materials, I suspect. The limit on nuclear proliferation has more to do with precision engineering and refining radioisotopes. Replicators can definitely help with the first, and possibly with the second.

[Dave]

It's a bit hard to build a nuke in your basement in any reasonable amount of time and in secret, even assuming that a replicator can make all that parts for you.

The assembly is not difficult if you can procure the materials, I suspect. The limit on nuclear proliferation has more to do with precision engineering and refining radioisotopes. Replicators can definitely help with the first, and possibly with the second.

Dirty bombs are always a possibility, and IIRC most smoke detectors use radioactive isotopes for detection.

Heck, if you're doing that, you probably don't need a replicator to do it. It'd help, sure, but it wouldn't be necessary.

[Korto]

One way to do the true 3d on the cheap, is to print water onto plaster dust. The resulting plaster figure, can then be used to make a sand mold. Optionally, you can directly print the mold itself. Nonferrous metals can be melted in a microwave oven crucible, and poured into a plaster mold.

OK, I'm going to step in here and say for anyone wanting to try this at home that while simple like this may work for low-melting-point metals like lead and tin (personally haven't tried it), if you're doing anything like bronze (around 1000C), the plaster has to be thoroughly cooked in a high temperature oven or kiln first to remove all the moisture. Or you don't, and then stand back and watch the show. It's very impressive but fucks your casting.

Also. There is a lot you can make, if you are willing to go slow. For instance, if you were willing to use laser welded metal powder, instead of drop forged or molded.

This points to the main problem I see with the real "replicators" we have or may soon have, they're limited to thermoplastic. This laser idea could significantly increase the range of materials, but it still will have trouble with materials that wont lend themselves to the process, even common metal alloys that wont have the required properties if treated like that.

[adam_grif]

The assembly is not difficult if you can procure the materials, I suspect.

Not difficult by professional standards maybe, but it requires precision machining of components. "Gun type" is going to be much easier to build, of course, than an implosion, because it doesn't require the perfectly aligned & timed explosives. But still, it's not the sort of thing you could throw together in a high school metalworking class.

[Uncluttered]

Star Trek basically already has that kind of regulation because almost every replicator we ever see is physically built into a wall. That makes controlling the software a lot easier then if people can take a mobile one home in a free society. But in real life, people would rip them out of walls and steal them anyway. Star Trek is not populated with real people.

Nice! Makes you wonder why replicator theft wouldn't be an epidemic. Since we don't see gaping holes in the walls whenever they go planetside, they are doing something that counters this. Here's some ideas.

1. Quickly replacing replicators before the camera pans over. Maybe other replicators automatically beam in a replacement.
2. Maybe the replicators have a rawmaterial feed, like in Diamond age, and would be useless without the local utility company.
3. Somehow, no one has a need to take a replicator. A cultural taboo against it, or just a cultural taboo against clutter, which I can understand.
4. People who steal replicators are covertly murdered off camera, by Teletubbies.
5. They have developed replicator DRM, and everyone has a replicator, but can't make weapons, donuts, or anything harmful.
6. It really is a utopia, and crimes are rare.
7. Everyone is too busy laying about in pajamas to bother.

I'm leaning towars sollution #2, although #7 is very attractive too. What do you think?

[Uncluttered]

One way to do the true 3d on the cheap, is to print water onto plaster dust. The resulting plaster figure, can then be used to make a sand mold. Optionally, you can directly print the mold itself. Nonferrous metals can be melted in a microwave oven crucible, and poured into a plaster mold.

OK, I'm going to step in here and say for anyone wanting to try this at home that while simple like this may work for low-melting-point metals like lead and tin (personally haven't tried it), if you're doing anything like bronze (around 1000C), the plaster has to be thoroughly cooked in a high temperature oven or kiln first to remove all the moisture. Or you don't, and then stand back and watch the show. It's very impressive but fucks your casting.

Also. There is a lot you can make, if you are willing to go slow. For instance, if you were willing to use laser welded metal powder, instead of drop forged or molded.

This points to the main problem I see with the real "replicators" we have or may soon have, they're limited to thermoplastic. This laser idea could significantly increase the range of materials, but it still will have trouble with materials that wont lend themselves to the process, even common metal alloys that wont have the required properties if treated like that.

Here's an article on laser sintering. It's pretty cool. I have no hands on with it though.
http://en.wikipedia.org/wiki/Selective_laser_sintering
As far as the plaster casting. Yep. Moisture is an issue. The good news, is a few hours in a furnace will dry anything. The bad news is, your mold has to spend hours in the furnace.
Laser sintering might actually be quicker!

[Uncluttered]

lookie what I found

http://www.solidconcepts.com/content/pd ... Stocks.pdf
These guys made an AK-47 with laser sintering! Delivered next day!

If you can print an AK-47, you can print bullets with this.
The pulse rifle is caseless, but plastic isn't out of the question.


All you need is nitrocellulose and primer.

LV-426 is starting to look a little easier.

[lordofchange13]

Would a clanking replicator fit onto a typical household ? I imagine it would be an enormous construct bigger than the typical two story house. The idea that a tabletop machine can take raw material as input and output finished electronic or mechanical devices is hard to believe. You will have to fit the industrial base of a developed country on a miniature scale inside a replicator to make it useful.

star trek replicaters are actully the size of a travel case to a shirt cabinet.