This is a simple tool for cleaning your filament path and nozzle, and to clear blockages.

You will need a length of stainless rod, 1.5 or 1.6mm (1/16") diameter, 100mm length. You should be able to find easily on eBay.

To use, simply withdraw the filament, push the rod down the hole in the top of the extruder (while it's hot), push down until the filament stops flowing out of the nozzle, and withdraw. Usually, any crud will be stuck to the rod, and can be removed easily.

If anyone can suggest a better name for this tool, please tell me!