The bearing blocks were greased last week when I did the ballnut without any luck.

I'll upload some pictures of it tomorrow but the x axis is a piece of 120 x 60 mm aluminium extrusion with 8 mm walls.
The rails are positioned on the top and bottom with the ballscrew on the back with 20mm aluminium plates forming a box around around which seemed like an unusual design so I did try to see if it would twist when I first got it. I couldn't get it to twist, rack or alter shape at all. I've also made sure everything is square.

I'll try it again tomorrow just in case and also check each block when they're disconnected from everything else.