Here is the base section being machined. I had to skim cut the bottom to get it to lay reasonably flat on the table.



Then I flipped it over and machined the filter part. I wound up taking it out about 1/8" on each side and taking out the taper that was left by the mold plug. This is called draft and is on nearly all mold plugs to allow the plug to be removed from the molding sand.



The filter fits in the base, now on to the top.