So, what have I learnt so far?
- Sarrus' linkage looks extremely good on paper and You Tube
- Stability depends on the play in the hinge and the stiffness of the support plates.
- There has to be a more efficient way to do this, material and space wise.
The problem came in the arrangement of hinges. In order to save space, I opted for under platform hinges. This limits the placement of the hinges because they cannot occupy the same space. Additionally the support beams are not rigid enough by any stretch of the imagination, being designed to resist pulling forces, but not worth much in terms of lateral support...
It will be extremely hard to have the stability you need over the whole platform without placing the plates on the outside and on all sides, making it a bit ungainly.
Looking for plan B... and I think I have an idea. A crazy one perhaps