well it takes little longer LOL . hows that .
But you don’t need multiple crucibles and you don’t need to have one form for a single part .
If your forms are large enough , you cast multiple parts in that one form . Linking all to one reservoir.
The reservoir is the key to casting multiple parts
So in reality your only confined by the size of your furnace , crucible and forms .
The foundry set I linked to has a big enough crucible to melt enough brass to cast 3 average size TG .
The form though is only big enough to make one and hardly big enough for that .
Thus I have build a 24 x24 set of forms as well as a 36 x 24 .
In that set of forms I normally cast in two pours but in one melt .
IE there are two reservoirs that connect to the surrounding parts .
So when im using that form . I may be casting 2 TG’s , 4 thumb inlays and 3 or 4 sights , all at one time .
Myself I always try to cast as many as my form will hold . IE if your going to melt enough material anyway , you might as well use it .
Sometimes you even get lucky and can make multiple castings from the same sand mould . Draw back though is that each time you do that , you lose detail. So normally you want to make a new cope and drag each time
Now what can be a pain is butt plates . They can take multiple forms , stacked together to make a single butt plate mould . To get around this , I started doing lost foam casting for parts that have negative angles .
You do loose the pattern. But they are much more easily made from foam so .
But you can also get a cleaner casting because you don’t have to remove the pattern
So lets say im doing castings for a rifle .
I ll set up a mould for the BP . Then a mould for the TG . If there is to be a cast thumb piece or RR pipes , then those parts will be part laid up so as to be cast at the very same time as the TG . IE the are in the same form / Same sand mould .all connected to the same reservoir
I then pour to that mould first because it will need better flow properties . . Once that mould pops , I pour to the BP .
So really no magic . Just Proper prior planning