The Mrs aint gonna be happy about this little project!

[Jonathan]

That would be very tricky to do as the box section is 60mm and the rail base plates are 65mm

The SBR25 rail base is 55mm wide unless I'm missing something?

There's no way im going to be able to bend the box section. I'd expect the ali back plate to bend before the steel.

We're only talking small fractions of a milimeter which doesn't require that much force. Both will bend a little bit...

What could you get the ballnut mount down to?

About 160mm if you're happy being limited to only using 1:1 or 1:2 ratio without changing the belt. Don't quote me on that though as I need to draw it first!

Back plate is 2190x330x20mm.......quoted.......wait for it........£300 +vat for ecocast!!!
5038 is £205

It would be fine with 1/2" thick plate, but that doesn't really change the conclusion as it's still expensive.