Most people do not run the center screw in the center on carpet. However, you can also use a small aluminum nut. You will probably find that the motor will hit the T-bar. You can use a dremmel to bevel the surface or purchase a T-bar from PRC that is already notched for you. Other option would be to use a smaller spur whitch will also give you more motor room. I'm using a 96 spur in stock at most times.

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