Delonghi Dedicat grinder (KG521) adapter

Re-design inspired from https://www.thingiverse.com/thing:4929161 by kurisutofuJP.

This is an adaptor for the 51 mm DeLonghi portafilter to be used with the DeLonghi coffee grinder (KG521).
There already is an adaptor provided with the grinder but I found it too messy as it lets coffee spill easily.

Feature added :

• notches to keep the filter in place while grinding
• inside structure to make arms stronger.