Revision as of 15:32, 26 August 2017

In advanced gem-gum factories the production and consumption rates of the meeting assembly levels should roughly fit together such that no bottlenecks are present.

To compensate for mismatches of the throughput of the assembly cells of specific size levels one can chain together several of the same assembly levels with pervasive transport paths (in case the assembly levels are implemented as assembly layers the chaining is stacking and the transport paths vertical shafts going up through the homogeneous stacks) This stacking approach works only as long as transport up the stack is can be faster than the assembly in the stack which is especially true for the bottommost assembly layers. (TODO: check for upper layers)

Mismatch

In the case throughput capacity monotonously increases with rising assembly levels it can at least speed up recycling where the old products don't go down all the way the convergent assembly stack.

A drop in throughput capacity with rising assembly levels is harder to justify. pre-assembled matter memory "caches" that convert back and forth never reaching macroscopic dimensions may be a motivation.

It's hard to guess where in the stack the demands (lower bounds) will first push at the physical limitations (upper bounds).

Factors determining throughput rates for individual assembly level chambers

To match the the throughput of the assembly levels one needs to at least roughly estimate the actual the production rates of the assembly levels of advanced gem-gum factories. They depend on:

Density in space

The density of operational spots of the assembly method.
Hard-coded mill style (spots are dense) or general purpose manipulator style (spots are sparse).

Density in time

Dissipation power (depending on operation speed) and cooling system capacity.
On the lowest levels surface area increases thus one might want to slow down a bit.

Convergent assembly step size

The step sub-product sizes between the assembly layers ("step size"). How many small parts will be assembled to a big one.

Assembly robotics geometry

Especially in the bigger assembly chambers that lie in the higher assembly levels it becomes possible to do "streaming". First one merges the incoming small building parts into a single stream and then one feeds this stream through moving hinges in the assembly robotics one delivers the parts to their destination in the block the next assembly level up.

Note that the merging of streams (between assembly levels) in the bigger size range (towards macro) is not not for ordering. At these levels the parts can already be produced in the right order making reordering unnecessary.

Even snake/tentacle like actuators feeding parts to their destination are a option.

The streaming of filament in an thermoplastic 3D-printer of today (2017) is a halfway correct analogy. There is streaming of building material but no fusion of streams of discrete building parts.

Less back and forth

Instead of going back and forth for each part one can stream parts directly to the tip of the manipulator.

• from ... -> pick U-turn -> transport-move -> place U-turn -> empty-back-move -> pick U-turn -> ...
• to ... -> U-turn -> place -> place -> ... -> place -> place -> U-turn -> place -> ...

Streaming works only if there is enough space available. Thus only in the higher assembly levels.

The gain in throughput rate should roughly be from two times the length scale of the assembly-level-cell under consideration to to one time the length scale of the sub-assembly cells.
This gives:

• Two times the convergent assembly step-size from this effect, which is pretty significant.

Less U-turns

In the simple pick and place case one has two tight U-turns of per placement operation where the big manipulator of the assembly cell under consideration has to turn around on the smaller length scale of the sub assembly cells. In the streaming case one has just one tight U turn per row/column (whatever you want to call it) of the product part.

• The number of necessary slowdowns divides by two times the convergent assembly step-size.

Related

• Level throughput balancing is an aspect of advanced nanofactory design.
• Higher productivity of smaller machinery
• Convergent assembly & Assembly levels
• Scaling laws