I'm still in the learning process but something like electrolyzing water would take an input hatch for the water, output hatch for the oxygen, input bus for the empty cells, and output bus for the oxygen cells. They can also share hatches/buses and use them as necessary instead of just the casings. They can't share maintenance hatches though and need their own.
Machines they support is in that graphic on the wiki. For things that use a mold or IC it's best to give a ULV hatch to the mold/IC and a ULV hatch to the input to be processed (I don't think parallel recipe work with these).
Also I noticed the lathe isn't working :x