with wip can duplicate items (all items) to infinity.

To create the "machine" must superimpose two wip and put a box below the last. To create the duplication should be put on one side of the first block and then wip on the same block a panel that will be placed above the first wip

then just simply send ANY item on the panel
to duplicate (duplicate will be visible in the trunk)

you can see the pictures for understand how work this glitch