Hello all, I could use some help with the design of this robot.

I was just about to cut the side panels and thought that the beater may be compromised by running on too large a dead shaft. The beater is 20mm thick 6061-T6. The current design uses a 10mm stainless shaft, and needle roller bearings that have a 14mm OD. The sides are 12mm UMHW, and there will be a thrust bearing on either side.

Option 1 (Current design pictured below) – 10mm bar, 3mm of material either side of the bearing
Option 2 – 8mm bar, 4mm of material either side of the bearing. (The Fingertech dead shaft is just under 8mm.)
Option 3 – 6mm bar, 5mm of material either side of the bearing.

What are your thoughts?

Thanks

Bar 1.pngbeater 2.pngHippobotamus beater bar.pngHippo5 - Angry hippo.png