SeeMeCNC Rostock MAX v2 Assembly Manual page 58

Now install two #6-32 nylon lock nuts into the three tower supports as shown below.
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. 4-37: Tower supports ready to go.
Fig. 4-38: Idler bearing support screws.
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