Update - I have now moved to a new design that better suits my needs.

https://www.printables.com/model/757443-eureka-mignon-dosing-cup-holder

Simple setup for a dosing cup for use with a Eureka Mignon. I always weigh before I grind into a dosing cup and then collect the grinds in there. It means I can have the next dose of coffee ready before the first coffee has been made. 

This stand means I no longer need to hold the cup while the coffee is ground. The tray will catch stray grounds, but at the height it is at you won't end up with many. Simply reach your finger behind to trigger the dosing. It will allow access to grind straight into a portafilter, but if this is what you want there are other remixes for holding a portafilter.

I designed it as a reasonably easy print in a material of your preference. It can be used without the tilted stand. The flap at the back is to link it securely with the machine. I would recommend tilting this grinder and using a hopper similar to what I've got on mine. I have the Eureka Mignon Specialita, but this should be compatible with a range of the Eureka Mignon grinders. Key measurements: rear is 69mm at part between eureka feet extensions. Height of stand from base is 140mm.

You can still use it with a portafilter, but it just won't hold it in place.