Bulk manufacturing on Luna will need to be done by automated or remote-controlled machines. Humans-in-spacesuits is too costly, as are pressurized, breathable environments. To control for temperature and dust, factories probably should also be enclosed, so again, the geodesic dome design is easiest for maximum area covered using minimal materials. Also, in some cases it may be best to pressurize the factory with an inert gas such as nitrogen or argon; that way ambient gas temperature can also be maintained, and equipment will not have to be engineered for hard vacuum.
Another big issue is getting product back to earth. The launcher mechanism will be described in the next section. But whatever is launched will need to land intact on Earth. I recommend atmospheric-entry gliders, similar to the X-38 or Shuttle Orbiter design. For efficiency, these should be remote-operated, so it is probably easier to have them land on skids in the ocean.
ELECTROMAGNETIC MASS DRIVER:
This is a large mag-lev track, with a huge mesh cradle mounted on the track. The loading/unloading point on the track is nearest to the Luna base.
The cradle accelerates its payload to Lunar escape velocity and releases the payload in a tangential trajectory. The trajectory will be bent somewhat by Lunar gravity in a spiral form as the payload moves up and out of the Lunar gravity-well. So the launch-point and speed need to be calibrated so that minimal energy is needed to manage the path of the payload once it is launched.
The mag-lev track will probably be the main consumer of electricity, hence the need to store electricity in compulsators.
This is essentially the reverse of the launcher function. The cradle accelerates to match the decaying-orbit velocity of the descending payload, which makes a low-energy landing on the cradle. Then the cradle can use the electromagnets to decelerate to a stop.
The launcher performs several functions:
a. Send drop-gliders back to Earth to deliver manufactured product.
b. Send manned vehicles back to Earth.
c. Launch very large interplanetary probes.
d. Receive supplies and, if safe, receive manned vehicles.