Here is a piece that I cast using the above hard-brick furnace, to give an idea of the size and weight of an object that can be cast with this size brick furnace using a #10 crucible.
With runners and sprue, the total poured weight was probably 6.5 lbs.
I could probably pour about 10 lbs aluminum maximum using a #10 crucible.
Its an 8.6" diameter flywheel; finished machined weight is 5.0 lbs. (356 aluminum).
A single wood spoke was hand carved first, then six spokes cast from that pattern, and then the spokes assembled with a wood hub and rim.