SeeMeCNC Rostock MAX v2 Assembly Manual page 46

Now install the 12 #6-32 Nylon lock nuts in the locations shown in Fig. 4-29. Make sure the
flat faces of the nuts are facing "out" towards the edge of the part, just like you did for the three vertical
supports.
Fig. 4-29: Installation of the Nylon lock nuts.
Each tower support holds the idler bearing assemblies that you put together. In order to install
them, you'll need to add a #6-32 washer to two of the #6-32, 1-3/4" Stainless Steel flat head screws
and insert them into the back of each stepper motor mounting plate as shown below:
Rostock MAX v2 Assembly Guide
Fig. 4-30: Idler bearing screws installed.
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