Hay DaveT1963 is your use of XOP I beam still working out for you are you still having to work out some bug's .Your design looks to have more strength to it.like you sir I am not little guy and see the advantage' of using that I beam.I am not putting down any of the other designs but if you are going to use hollow tubeing and then have to fill it in with plastic, wood or putty to keep it from deforming the tubeing, you are probly not saving that much weight over using the I beam in the first place.I just want to say thank you for your video and I am going to use your current design to start my platform.