What is your recomendation for gantry sides

[routercnc]

The deflections are only based on generic cutting forces for each material, not any particular feed rate. Doing it this way allows you to make simple comparisons and see relative performance from different designs, and that is all the spreadsheet was design to do.

There is lots of information on the internet relating to feedrate, number of flutes, depth of cut and chip load but this was not the objective of the spreadsheet as chip load is a topic in itself.