SeeMeCNC Rostock MAX v2 Assembly Manual page 123

Assemble an idler bearing out of two black plastic bearings spacers and a 608ZZ roller bearing.
Install it into the upper tower mounting as shown below. Use a #6-32 1-3/4" pan head screw and a #6-
32 Nylon lock nut to hold it in place. Don't tighten it – we'll do that after the belts are installed.
Repeat this step for the other two idler bearings.
Rostock MAX v2 Assembly Guide
Fig. 9-5:Idler Bearing installed.
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