Usually just mark you as an idiot incapable of basic reading and understanding and move on but since you provoked me and waiting for some email.

Perhaps the point wasn`t clear enough, I`m not involved in your imaginary argument with an invisible opponent about stage collapses.

Sorry that brought that up as an example of how truss is not able to withstand forces in all directions, but it is a very clear example.

Your just not able to maintain concentration for more than two sentences and your unable to understand what is written.

You then blame those attempting to help you for your lack of understanding, you don`t think, you expect to be spoon fed every item.

The question was posed what advantage do you expect to acheive with a open webbed truss gantry?

If lower mass than say a steel I beam, to what advantage?

Lowering mass may result in more possible resonance ,that would most certainly may have an effect of machining.

You haven`t read this far though, you think you have invented a revolution in moving gantry routers, anything that makes your idea less than the invention of the wheel is to be discarded and insulted, thats why there isn`t loads of commercial machines with lightweight truss gantrys, sure Boeing will be on the phone to you shortly....