3D part as replacement of the fragile button guard of the EMCO F3 mill. Possibly fits other Emco machines from the same period. 

The guard is designed for the buttons that move the mill in x, y, z direction. The printed guard snaps into place just as the original. Keeps dust from the buttons and avoids unintended operation. 

Recommended to print in PETG and with 0.25 nozzle. It took some time to get the print settings right - see 3mf file for support and rim. 
If the snap-in is not perfectly tight, try to enlarge print by a few percent.