Where you have more than 2 tool arms needing a place to live
I dont waste time retooling the arms, I have them mounted and I change out the arm as one assembly/ Its faster switching back and forth that way
I am set up with arms for the 10 inch contact, 3 inch contact and slack belt combo arm, small wheel arm, 44 radius platten. That's 4 arms currently and since only one can be used at a time I have to put the other three arms somewhere when they are not being used. If this doesn't make sense to you, then I am not sure I understand your question
Mine mount on the wall of my shop when not being used, not the grinder