Hi One Rod
How is the lift going to work?
By the remorseless power of hydraulics.
Plan A was to use a trolley jack, as I thought that would keep things simple.
However, because the lift arm on the jack and the PM arms on the bench are different lengths, making it work properly leaves you with a couple of design choices.
First is to allow the jack to do what trolley jacks do, roll backwards and forwards as it raises and lowers, to compensate for the different radii of motion. This means having a solid base or some kind of trackway in the base frame, capable of taking the full load. It also seemed to mean that the fully-lowered height was more than I was happy with.
The other choice was to remove the wheels and weld the jack chassis into the base frame, with the lift arm pivot exactly concentric with one of the PM pivots. All good unless the jack ever failed and needed fixing. The only way would be to cut the whole thing apart.
I guess neither problem would be insurmountable, with enough ingenuity. But it still seemed to be making things more complicated, not less. Besides, by then I'd found this on Ebay.
8 tonne lift capacity and an impressive ram extension.
Seems as though it might simplify things considerably. Still left me with one really puzzling question, though.
How do the Chinese manage to make this thing, ship it half way around the planet, and drop it on my doorstep, all for £24.99?