A bit of marking time today. This is pretty much completely unnecessary for a small table like this, but I just find making grids quite satisfying!
Actually there is a little method in my madness - all my benches are set at the same height, and I’ve planned for this to be 85mm (say 3 1/2" or thereabouts) but since I had a couple of scraps of 16mm (about 5/8) MDF and an 8mm one as well (3/8?) I’m using the thinner one on the bottom, a thicker one on the top and a thicker one for a spoil board.
If I do get round to making a larger table in the future, it will be with 4mm skins and 60 mm bars and a few other tricks. Note that a torsion box can make a great amplifier of noise (think guitar or drum) so with thin skins in particular some thought might be necessary to minimise sound transmission. For now, that’s the least of my worries! 
