Residue left on the nozzle can cause prints to be contaminated and first layer printing to fail, which is not good. Simply quick removing nozzle residue before starting to print.

Print settings: 

• Material: High thermal resistance filament are recommended.
• Layer height: 0.2mm
• Supports: no
• Perimeters: 2
• Infill: 15%

It is assumed that one thing cannot be used indefinitely, and that when it is damaged, a new one should be printed.

Update 17/08/2022:

The shape design has been significantly changed, making it even easier to use.