[ParkerF]

I would be careful on how you do your lower flanges on both plates.

The lack of a lower flange on the outer plate makes you vulnerable to bending along that whole edge. It could easily cause havoc to any bearings you may have placed in the plate.

Additionally, cutting your flange on the inner plate for the gearbox has a similar effect. You lose a lot of rigidity in the whole drive structure because that length of plate now has a nice spot to bend. Imagine taking a load straight through your direct driven axle and how that area will deflect with or without the flange.

-Parker