Slimefun Machines, namely things like Electric Gold Pans, Sifters, Grinders, will, after a number of uses, break. To maintain balance or something like that, T1 machines should have several hundred uses each, T2 should have about a small thousand, and so on. In order to compensate there should be T4 and T5 machines that require more expensive crafting recipes. On top of all that, Molecular Reassemblers, after its expiration, should have a chance to explode, reducing the durability of nearby slimefun items.
In order for players to not go absolutely insane, T5 shouldn't have durability, and all T3 machines that are currently placed down should become the illusive T5 machines.
-Addendum: MadeinChinalol said for the crafting recipe for T5, add in Reinforced Alloy Blocks, made of Reinforced alloy plates.
-Addendum: Durability should be as follows on average per tier; T1 should have 1400 uses; T2 should have 3500; T3 should have 7000 uses; and T4 should have 9800
-Addendum: Add the wrench as a rare item that allows to repair machines with low durability, for balance, make it uncraftable and needs to be found or won in anniversary crates