[extropy-chat] Re: Towards Self-Replicating Rapid Prototypers

[Adrian Tymes]

Neil Halelamien wrote:
> http://staff.bath.ac.uk/ensab/replicator/

Checking the details...

> While I am talking of what I mean, and before
> arguing why this is so important, let me say exactly
> what I mean by "make a copy of itself". I mean a
> rapid-prototyping machine that can make all its
> components other than:

> Self-tapping steel screws
> Brass bushes,
> Lubricating grease,
> Standard electronic chips such as microcontrollers
> and optical sensors,
> A standard plug-in low-voltage power brick, and
> Stepper motors.

> This list is an attempt to make a compromise between
> immediately-achievable technology and the desirable
> aim of shortening or eliminating it altogether.

*cough*yaright*cough*

True, it is desirable not to do more work than
necessary; unfortunately, true self-replication does
not all that degree of shortcutting.  Screws and
bushes should be easy to create; power bricks, not
that much harder since they are explicitly fabricating
electrical components.  Grease is allowable as an
exception: it's enough of a raw, bulk material that it
could qualify as feedstock.

Motors and chips are the real killer.  Granted, it's
hard to create them with the same kinds of tools that
one would, say, make panels and rods with.  But that
doesn't mean one can credibly claim "self-replication"
by leaving those out.  (Indeed, I recall an earlier
effort that managed to self-replicate *everything*,
including the motors, except for the chips.)  Which is
probably why any real effort towards self-replication
should focus on an ability to build the tools that can
automatically build motors and chips: everything else
is easier in comparison.  (Nor does this require
advanced lithography: if you can accept a low clock
rate and high power consumption - self-rep doesn't
always have to be fast and efficient - then one could
take large slices of silicon and weld copper traces
onto it, and force-implant impurities where
transistors are needed.)