Note: Legacy documentation is no longer being updated. For up to date instructions, see our Troubleshooting support articles.
The plastic cylinder that prints the rear left-hand corner of the print bed is a purging routine that records the thermoplastic layer history. We call it a reference part - it is only produced when both nozzles are used (during a fiber print). Like the rings of a tree, this cylinder represents the layer history and thermoplastic history of your part.