Do you mean your gantry across beam ?

If so then yes what you have will be ok, if you wanted to go a step further and add a dampening effect, you could fill the extrusion with kiln dried sand as a relatively cheap and easy solution or go for something a little more upmarket and use an epoxy granite mix, the later being commonly used as a material for building machine bases...better vibration damping...better tool life and so on.