Material strengths for mounting plates

[Rogue]

Time for another MS Paint picture, I know how you love them so

I hope to mount the motor "internally" to the axis, so both the shaft and screw extend out in the same direction and can be connected by a pulley/belt system.



The initial plans used a lovely thick block of aluminium for this - until I realised that the motor shafts aren't all that long in the first place. The second version (I think there's another picture I posted somewhere already) involved a pocket milled into the material to make it thinner where the motor mounted. This second version is No. 1 in the picture.

The question I have now is whether a pocket like this would substantially weaken the mount or otherwise weaken it in a way that makes it pointless, and what thickness is actually needed for a decent motor mount?

Is there a real benefit to using a thick mount, compared to a thinner piece with a standard mounting block, as in No. 2 in the image?

Edited to add: In the first image, the ballscrew is held by bearings (the green bit) in a pocket milled into the mount. In the second image, the ballscrew is held by a traditional bearing block (the green bit) or similar.