Best Ways to Increase Rigidity?

[DavidSohlstrom]

Here are a threads where I talk about how I may go about increasing rigidity.

Width of gap X axis makerslides

Could some one measure the gap between the makerslides on the X axis. I am thinking of sandwiching a piece of steel flat bar between then and make it tall enough to just clear the top of the carrage and drop down and just clear the bottom on the carraage. Thank you Dave

Dave