Self-replication is the key overlap between von Neumann probes and the Machine described here.

A fully self-replicating machine requires these processes:

  1. collect raw resources
  2. process raw resources into components*
  3. assemble components into a new Machine
  4. copy instructions to new Machine
  5. start the new Machine

Of these, 4. and 5. are relatively trivial, while 1. is very environment-specific. The interesting questions are:

A. What are the minimum component types necessary to build a self-replicating machine?
B. How can these components be constructed from the availale raw materials?

A and B feed into each other, as more complex components (say, integrated circuits) require more complex refining techniques, which in turn may require more complex components.

I hypothesize that there are actually very few core components (provided speed of reproduction is not a priority):

  • solenoid (for relay-based memory)
  • motor/generator
  • conductive/structural material
  • insulating/structural material

Anyone have any other thoughts on minimal components for a self-replicating machine?

My main issue is seeing how a solenoid or a generator can replicate itself without some quite advanced machinery? I can’t even think of a way to do that in theory, much less in practice

Fair enough—I glossed over some steps. :stuck_out_tongue:

  • Certain configurations of coils of conductive material with structural elements can create solenoids.
  • Certain configurations of coils of conductive material with structural elements can create motor/generators.
  • Motor/generators + solenoids can create servo motors.
  • Servo motors + some structural elements can create robotic arms. This lets you assemble components.
  • Solenoids can act as relays, which allow the same function as transistors (so now you’ve got memory registers). This lets you build a computer and memory to store and run programs.
  • Motor/generators + structural components can create wind turbines for power.

So given the ability to 3D-print conductive coils, your machine can build components to generate power, move objects around physically, and run programs.

The step I’m missing is how to build some form of 3D printer from robotic arms, servos, solenoids, power, and structural elements. Or are there other essential components (perhaps heating element, wheel/pivot)?

Initial thought is to avoid 3D printing all together and use lego-style conductive or insulating blocks for construction.

How does a solenoid and a motor become a servo?

How do you create a machine using only servo motors that is capable of creating itself? Creating a machine that can make motors from raw material is no small feat. I’ve yet to see anyone successfully print conductive parts with enough resolution and with good enough materials to actually be useful.

If you could 3d print something like a stepper motor using a 3d printer that uses stepper motors then you are suddenly heading somewhere I can follow. This would also allow fairly easy printing of heating elements and similar

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Here’s an example of a servo with just a solenoid and a wheel (and gravity):

For a robotic arm, you could either use a stepper motor like in the video above, or if you want faster translation a motor with a solenoid to lock it once it’s in the correct position.

Any suggestions for free easy-to-use CAD-like software for sharing designs?

There is actually quite a few CAD programs that can be utilized freely - I believe OSE uses freecad, but there is also openscad and perhaps onshape

As for linear motors, sure, but I doubt there much easier to make and control than regular motors

I guess one thought that might be useful would be to look at uhwmp plastics - they form them with kind of ‘spinnerets’ in a neutral gas if I remember, which allows them to do things to make them really durable, like for use in medical implants and stuff. And also there are plastic semiconductors like … it’d be neat if there was a way to grow some kind of mostly biodegradeable supplies using genetically engineered corn plastics or spider silk or… something.