To collect a single MF Left Click it and then select the yellow "Collect ##,###" Button.
All Metal Factories & Oil Pumps may be collected simultaneously by Left Clicking anyone of the them and selecting "Collect All".
The MFdoes not have to be full to be collected. A common practice is to collect or "reset" them prior to logging off thus allowing it to produce for the maximum amount of time before the player can log back in.
Once the MF has reached its full capacity it will cease to produce any further amounts of metal until the player physically empties or "Collects" all the previously produced metal. Reaching capacity is signified by the halting of the animated movement and the displaying of a large red exclamation mark above the factory.
Once produced the metal must be "Collected" or moved to theMetal Storage building in order to be utilized or "spent" by the player. If there is insufficient room in the storage to hold all the currently produced metal only a partial portion will be transferred leaving the remaining amount in the MF.
The player receives Experience Points for the metal produced by the MF but only at the time it is collected and placed in the Metal Storage. This is calculated as follows : 1 xp per every 50 metal collected.
The MF only consumes power from the Power Plants while it is producing metal. Once it has reached its full capacity the power draw of the MF will return to zero until it is collected again.
As the player's upgrade needs rise in levels the usefulness of the metal factory diminishes forcing the player to seek additional resources elsewhere ( Enemy Player Bases, Rogue Basesor Deposits ).
Even when not producing the MF's can be useful to the player as a form of Barricade. As with all non destroyed buildings a attacking ground force will usually make a path around it assisting the defending player in herding the enemy into a exposed positions or slowing their forward progress.
Metal Factories is one of two buildings that are also known as Producers the other being the Oil Pump.
Metal Factories like the Oil Pumps are usually considered low priority and placed outside the main defenses when designing a Base Layout due to the relatively low amounts of resources they hold.
Like any other Kixeye games the resource used to upgrade the building is never the resource that the building produces.
The Maximum Capacity of the Oil Pump was increased and thus so was the Time to Max Capacity in the Game Update: Mar 5th 2014.