Deliberate slowdown at the lowest assembly level
When going down to the nanoscale the "surface-area to internal-volume ratio" rises
This is a well known, if not the best known, scaling law.
So bearing area increases.
With (wearless) friction power loss being proportional to bearing area
this loss (and waste heat) increases.
Add to that inefficiencies in the mechanosynthesis process. Which are hard to optimistically estimate.
Even easy highly pessimistic estimations lead to viable designs.
The most effective way for decreasing friction is by slowing down operations.
dynamic friction, that scales with speed squared, this especially pays off.
But won't things becoming too slow then to be practically functioning?
Fortunately when going down to the nanoscale with robotic devices then productivity rises
A barely known, if not the least known, scaling law. Maybe because nature barely exploits it?
This nicely compensate a good deal for the slowdown. And thus the friction issue.
There are other compensating effects too. See main page: Friction.
Due to level throughput balancing nanofactories will at the bottom-most assembly levels (where mechanosynthesis happens) strongly deviate from a stack of single layers (of exponentially growing size) with the height of a single cell for each layer. Instead with a slowdown (as explained why above) present when going upstream the manufacturing convergent assembly the lowers assembly layers need to be made to be stacks of cells of the same size.
These chains of mechanosynthesis assembly chambers (filled with manufacturing lines for in mass needed standard parts) may e.g. operate slowly horizontally instead of vertically. The here vertical transport of the finished base parts up to the second assembly level takes up many lines into one and thus needs to operate much faster. This is not a problem since the transport path for a finished crystolecule is minute compared to what needs to be moved to mechanosynthesize that said crystolecule.
Slowdown at the second assembly level?
At the second assembly level there is much less if at all any reason to slow down (and stack assembly cells of same size). Due to:
- (1) the considerable bigger scale => less bearing area
- (2) the less energy turnover intensive assembly processes being present (even covalent welding is only on surfaces, and VdW force is weak in relation)
Probably models needed to determine what is going on.
"Slowdown" is to take in therms of absolute speed (like e.g. mm/s).
Or in terms of the deviation from the scale natural operation frequency which scales linearly with size.