Adapter to fit the circular Ryobi brush (RAKSCRUBM) to ant drill you want. All you need is the adapter, an M10x50-80mm, M10 Lock-nut and a large washer fot he bolt.

Print the part with the hex facing down, use support from the bed. I recommend to print with PETG, 0,2mm layer height and 50% infill for extra rigidity. 

Press the bolt trough the adapter to fit the head of the bolt in the hex-shape, place the adapter in the brush and add the washer and nut. Now you can use the bolt as a shaft in any machine you want.