Print in place, no supports. I printed mine at 0.3mm layer heights in PETG but I'm sure it'll work with other filament types and finer layer heights.

With mine the petg was slightly stringy and it was a little tough to move the rack initially but after that first movement the action was smooth.

The fit on the allen keys is also pretty tight initially but I just moved the allen key back and forth in there places to get rid of the strings and bumps. They should fit pretty snuggly after you move them back forth a few times.

Metric 1.5-5 includes the following keys:
1.5, 2, 2.5, 3, 4, 4.5, 5
Metric 5.5-10 includes the following keys:
5.5, 6, 7, 8, 9, 10

SAE 005-316 includes the following keys:
0.05, 1/16, 5/64, 3/32, 7/64, 1/8, 9/64, 5/32, 3/16
SAE 732-38 includes the following keys:
7/32, 1/4, 5/16, 3/8