Resources - minetest-mods/technic GitHub Wiki
Technic provides additional resources for building these machines.
Latex 
Latex is used for manufacturing rubber, which is heavily used for the medium- and high-voltage components within Technic. Latex can be harvested directly from rubber trees (look for the pale green/seafoam leaves) using the tree tap like any other tool. Rubber trees regenerate their latex supplies after about a day.