In the old days the size of spacecraft you could manufacture was limited by the quality of the materials available (specifically the old TL value) and some research time, finding better quality resources was required to manufacture bigger and bigger spacecraft. Since its removal people have floated some ideas around about if or how the size of spacecraft manufacturing should be limited again.
Issues
I doubt we can expect a whole rebalancing of spacecraft combat. So I won't expect anything fancy like ship size classes or whatever else is normally being suggested by people. Best I imagine is limits that are easy to implement and understand.
Quality of spacecraft manufacturing materials can be annoying to keep track of. Anyone that remember the old TL technology system might be able to remember having to figure out their current size limit and then design their spacecraft blueprint out from that. This is what I would say is one thing I don't miss about the old system, having 32 different spacecraft size categories. This might not be an issue right now, but I think it is good to keep in mind.
Technology has no baring on spacecraft manufacturing, it only affect which modules can be manufactured and the end result quality level of the subsystems on the spacecraft. The research time on some of the more advanced modules (FTL drives) are very very long though, and I doubt we want more of those boring time sinks.
There are no special infrastructure requirements to manufacture the biggest of warships. You just need a spacecraft factory, warehouses filled with the materials and a tiny space station in orbit. Yes you need to actually have harvesting operations and materials manufactured, but that doesn't have to be in the same solar system at all and can just be shipped to the spacecraft factory's city. You can have a tiny city with a population of 10 manufacturing gigantic spacecraft, and this can be thrown down anywhere in just a few minutes.
Ideas
Advanced metal resources (Magmium, Vulcium and Adamantine) don't play any role in spacecraft manufacturing aside from a stronger hull module. This could be one simple way to limit the size you can manufacture a spacecraft at, simply have the hull module type limit it. It has the added advantage of being easy to understand by players and designers alike. For example the metal hull module could limit the size to spacecraft that can normally spawn on the ground. Converting existing spacecraft blueprints to a system like this should also be simple for Haxus to do, or simply allow us to do at the time of manufacturing.
What we don't want is a meaningless research wait timer. So making it a patent research seems like it would be a bad idea and wouldn't solve the issues above.
Limiting spacecraft manufacturing size by city infrastructure could be done by having it require a spacecraft factory of increasingly bigger size with a lot of citizen jobs to operate, so a tiny city with a population of 10 can't make a gigantic spacecraft. Or it could require special buildings like a space elevator and more orbital infrastructure, as long as it requires the city to actually have workers. It would give reason to have larger cities for a shipyard, rather than just a tiny city with lots of warehouses.
Conclusion
There are plenty of options for limiting spacecraft manufacturing size. The ideas I mentioned above can't be the only good ideas, so do share your ideas and give feedback. I assume a mixes of ideas to limit spacecraft manufacturing size by multiple factors would be best, such as all the ideas I mentions or something like that.
Lets brainstorm!
Issues
I doubt we can expect a whole rebalancing of spacecraft combat. So I won't expect anything fancy like ship size classes or whatever else is normally being suggested by people. Best I imagine is limits that are easy to implement and understand.
Quality of spacecraft manufacturing materials can be annoying to keep track of. Anyone that remember the old TL technology system might be able to remember having to figure out their current size limit and then design their spacecraft blueprint out from that. This is what I would say is one thing I don't miss about the old system, having 32 different spacecraft size categories. This might not be an issue right now, but I think it is good to keep in mind.
Technology has no baring on spacecraft manufacturing, it only affect which modules can be manufactured and the end result quality level of the subsystems on the spacecraft. The research time on some of the more advanced modules (FTL drives) are very very long though, and I doubt we want more of those boring time sinks.
There are no special infrastructure requirements to manufacture the biggest of warships. You just need a spacecraft factory, warehouses filled with the materials and a tiny space station in orbit. Yes you need to actually have harvesting operations and materials manufactured, but that doesn't have to be in the same solar system at all and can just be shipped to the spacecraft factory's city. You can have a tiny city with a population of 10 manufacturing gigantic spacecraft, and this can be thrown down anywhere in just a few minutes.
Ideas
Advanced metal resources (Magmium, Vulcium and Adamantine) don't play any role in spacecraft manufacturing aside from a stronger hull module. This could be one simple way to limit the size you can manufacture a spacecraft at, simply have the hull module type limit it. It has the added advantage of being easy to understand by players and designers alike. For example the metal hull module could limit the size to spacecraft that can normally spawn on the ground. Converting existing spacecraft blueprints to a system like this should also be simple for Haxus to do, or simply allow us to do at the time of manufacturing.
What we don't want is a meaningless research wait timer. So making it a patent research seems like it would be a bad idea and wouldn't solve the issues above.
Limiting spacecraft manufacturing size by city infrastructure could be done by having it require a spacecraft factory of increasingly bigger size with a lot of citizen jobs to operate, so a tiny city with a population of 10 can't make a gigantic spacecraft. Or it could require special buildings like a space elevator and more orbital infrastructure, as long as it requires the city to actually have workers. It would give reason to have larger cities for a shipyard, rather than just a tiny city with lots of warehouses.
Conclusion
There are plenty of options for limiting spacecraft manufacturing size. The ideas I mentioned above can't be the only good ideas, so do share your ideas and give feedback. I assume a mixes of ideas to limit spacecraft manufacturing size by multiple factors would be best, such as all the ideas I mentions or something like that.
Lets brainstorm!