Thanks for the clarification. I do have some different recollection of events about machine being rock solid after big profile and without any reinforcement need. But i am getting old and my memory is all screwed up. Lets move along.
i also do not understand you picture either. there is no space b/w ballnut and channel, how this reinforcement was done. was there any cut made in the reinforcement channel? i essentially end up doing the same thing as in the picture but with separate pieces. oh well ....