Last week was busy, but made a sketch of traditional hydraulic toe jack. Bought cheap 2t bottle jack and checked it. I could not trust it to support any load near my fingers - clogs, wedges and timber.
Therefore "Plan B": Screw jack type.
First scissor jack I checked seemed to have nice thread but plastic nut...don't get me wrong, I think that plastic can be used an lot of stuff but I would not buy cheap lift and use it, sooooooooo I looked up on table of the metric screws and whilst M10 seems to be a little marginal to lift one end of the 1t machine, M12 seemed to have enough security. Some more doodling and quick visit to local nut n' bolt shop produced 180 mm thread length M12 bolts with 19 mm AF hex. I wanted to have normal hex head - easier to use standard ratchet wrench and avoid using bar, etc.
Hard look on the corner of my dungeon and with a bit digging I found 50 mm C-channel, 40*100 mm L-section, flat bar and round bar. All hot rolled and least somewhat weldable. Hardest part was to decide how to mount the screw to minimize side load - all tables assume that the bolt/nut is mostly in pure tension (no bending). Decided to use classic round dowel nut/pivot design. Now this 180 mm length does not look too long anymore....on my disposable all welded structure there were no problems to reach effective 100 mm lifting height for dolly, but half way I got this idea of making it more professional and easier to repair and I'm watching my daylight disapearing. Also I found that one 25 mm bar that has carbon inclusions and eats my drills....now I have to paint/mark it to be used only where crappier iron will do.
Got to the point where I'm having most parts ready.